Chapter 31: Software Drawing, Time, and Graphical Gameslinear

Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: Symious <14933944+symious@users.noreply.github.com>
Co-authored-by: Jun Kawasaki <jun784@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

86 files changed, 2276 insertions, 242 deletions

diff --git a/src/main/c/simple_audio.c b/src/main/c/simple_audio.c
new file mode 100644
index 00000000..b8ed62de
--- /dev/null
+++ b/src/main/c/simple_audio.c
@@ -0,0 +1,40 @@
+#include "simple_audio.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dlfcn.h>
+
+static const struct simple_audio_api *api;
+static void *library;
+
+int32_t simple_audio_open(void) {
+    const char *path = getenv("SIMPLE_MINIAUDIO");
+    if (path && strcmp(path,"off")==0) return -1;
+    if (!api) {
+        if (!path || !*path) return -1; // Optional: games may run silently.
+        library = dlopen(path,RTLD_NOW | RTLD_LOCAL);
+        if (!library) {
+            fprintf(stderr,"Simple audio: cannot load backend '%s': %s\n",path,dlerror());
+            return -1;
+        }
+        const struct simple_audio_api *(*get_api)(void) =
+            (const struct simple_audio_api *(*)(void))dlsym(library,"simple_miniaudio_api");
+        const struct simple_audio_api *candidate = get_api ? get_api() : NULL;
+        if (!candidate || candidate->version!=SIMPLE_AUDIO_VERSION || !candidate->open ||
+            !candidate->load || !candidate->play || !candidate->stop ||
+            !candidate->playing || !candidate->close) {
+            fprintf(stderr,"Simple audio: incompatible backend; rebuild with make audio.\n");
+            dlclose(library);
+            library=NULL;
+            return -1;
+        }
+        api=candidate;
+        atexit(api->close);
+    }
+    return api->open();
+}
+int32_t simple_audio_load(const int16_t *samples, uint32_t count) { return api ? api->load(samples,count) : -1; }
+int32_t simple_audio_play(int32_t sound) { return api ? api->play(sound) : -1; }
+int32_t simple_audio_stop(void) { return api ? api->stop() : 0; }
+int32_t simple_audio_playing(void) { return api ? api->playing() : 0; }
+int32_t simple_audio_close(void) { if (api) api->close(); return 0; }
diff --git a/src/main/c/simple_audio.h b/src/main/c/simple_audio.h
new file mode 100644
index 00000000..77cce530
--- /dev/null
+++ b/src/main/c/simple_audio.h
@@ -0,0 +1,16 @@
+#ifndef SIMPLE_AUDIO_H
+#define SIMPLE_AUDIO_H
+#include <stdint.h>
+
+// Main-thread API. Samples are copied; no Simple heap pointer is retained.
+struct simple_audio_api {
+    int32_t version;
+    int32_t (*open)(void);
+    int32_t (*load)(const int16_t *, uint32_t);
+    int32_t (*play)(int32_t);
+    int32_t (*stop)(void);
+    int32_t (*playing)(void);
+    void (*close)(void);
+};
+#define SIMPLE_AUDIO_VERSION 1
+#endif
diff --git a/src/main/c/simple_crt.c b/src/main/c/simple_crt.c
index 438ae5f9..39708629 100644
--- a/src/main/c/simple_crt.c
+++ b/src/main/c/simple_crt.c
@@ -6,6 +6,19 @@
 #include <termios.h>
 #include <unistd.h>
 
+// Fixed-semantics compiler intrinsics. Keep these definitions for indirect
+// calls; direct calls may inline to representation-preserving register moves.
+int64_t simple_f64_bits(double value) {
+    int64_t bits;
+    memcpy(&bits, &value, sizeof(bits));
+    return bits;
+}
+double simple_f64_from_bits(int64_t bits) {
+    double value;
+    memcpy(&value, &bits, sizeof(value));
+    return value;
+}
+
 // errno may be thread-local or a macro calling a platform accessor.
 int32_t simple_errno(void) { return errno; }
 int32_t simple_set_errno(int32_t error) { errno = error; return -1; }
diff --git a/src/main/c/simple_graphics.c b/src/main/c/simple_graphics.c
new file mode 100644
index 00000000..40d66ba9
--- /dev/null
+++ b/src/main/c/simple_graphics.c
@@ -0,0 +1,102 @@
+#define _POSIX_C_SOURCE 200809L
+#include "simple_graphics.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dlfcn.h>
+#include <unistd.h>
+
+#ifdef __CYGWIN__
+#define BACKEND_NAME "simple_minifb.dll"
+#define BACKEND_ABI "x86_64_v2_win64"
+#else
+#define BACKEND_NAME "libsimple_minifb.so"
+#define BACKEND_ABI "x86_64_v2_SystemV"
+#endif
+
+// Executable-relative paths work even when launched outside the checkout.
+// Working-directory paths also cover test executables and chapter/root shells.
+static void *find_backend(void) {
+    char executable[4096], path[8192];
+    ssize_t n=readlink("/proc/self/exe",executable,sizeof(executable)-1);
+    if (n>0 && n<(ssize_t)sizeof(executable)-1) {
+        executable[n]=0;
+        char *slash=strrchr(executable,'/');
+        if (slash) {
+            *slash=0;
+            const char *relative[]={"/" BACKEND_NAME,
+                "/../../release/" BACKEND_ABI "/" BACKEND_NAME,
+                "/../release/" BACKEND_ABI "/" BACKEND_NAME};
+            for (unsigned i=0;i<sizeof(relative)/sizeof(*relative);++i) {
+                snprintf(path,sizeof(path),"%s%s",executable,relative[i]);
+                void *handle=dlopen(path,RTLD_NOW | RTLD_LOCAL);
+                if (handle) return handle;
+            }
+        }
+    }
+    const char *relative[]={"./" BACKEND_NAME,
+        "./build/release/" BACKEND_ABI "/" BACKEND_NAME,
+        "./chapter31/build/release/" BACKEND_ABI "/" BACKEND_NAME};
+    for (unsigned i=0;i<sizeof(relative)/sizeof(*relative);++i) {
+        void *handle=dlopen(relative[i],RTLD_NOW | RTLD_LOCAL);
+        if (handle) return handle;
+    }
+    return NULL;
+}
+
+// No MiniFB headers or link dependency in the default runtime. Cygwin's
+// dlopen also loads native Windows DLLs; both use the x64 Windows C ABI.
+static const struct simple_graphics_api *api;
+static void *library;
+
+static int load_graphics(void) {
+    // Explicitly disabling graphics also makes headless tests deterministic.
+    const char *path = getenv("SIMPLE_MINIFB");
+    if (path && strcmp(path, "off") == 0) {
+        fprintf(stderr, "Simple graphics: disabled (SIMPLE_MINIFB=off).\n");
+        return -1;
+    }
+    if (api) return 0;
+    int explicit_path=path && *path;
+    library = explicit_path ? dlopen(path, RTLD_NOW | RTLD_LOCAL) : find_backend();
+    if (!library) {
+        if (explicit_path)
+            fprintf(stderr, "Simple graphics: cannot load MiniFB backend '%s': %s\n", path, dlerror());
+        else
+            fprintf(stderr, "Simple graphics: MiniFB backend not found beside the executable or in build/release/"
+                    BACKEND_ABI ". Run make graphics, or set SIMPLE_MINIFB to its full path.\n");
+        return -1;
+    }
+    if (!explicit_path) path="automatically discovered backend";
+    const struct simple_graphics_api *(*get_api)(void) =
+        (const struct simple_graphics_api *(*)(void))dlsym(library, "simple_minifb_api");
+    const struct simple_graphics_api *candidate = get_api ? get_api() : NULL;
+    if (!candidate || candidate->version != SIMPLE_GRAPHICS_VERSION ||
+        !candidate->open || !candidate->present || !candidate->poll ||
+        !candidate->mouse_x || !candidate->mouse_y || !candidate->button ||
+        !candidate->key || !candidate->close || !candidate->wait) {
+        fprintf(stderr, "Simple graphics: incompatible MiniFB backend '%s'. Rebuild with make graphics.\n", path);
+        dlclose(library);
+        library = NULL;
+        return -1;
+    }
+    api = candidate;
+    // Keep the library loaded until process exit; its window callbacks may
+    // still be registered. Closing a window releases its native resources.
+    atexit(api->close);
+    return 0;
+}
+
+int32_t simple_gfx_open(const char *title, uint32_t width, uint32_t height) {
+    return load_graphics() ? -1 : api->open(title, width, height);
+}
+int32_t simple_gfx_present(const uint32_t *pixels, uint32_t count) {
+    return api ? api->present(pixels, count) : -1;
+}
+int32_t simple_gfx_poll(int32_t wait) { return api ? api->poll(wait) : -1; }
+int32_t simple_gfx_mouse_x(void) { return api ? api->mouse_x() : 0; }
+int32_t simple_gfx_mouse_y(void) { return api ? api->mouse_y() : 0; }
+int32_t simple_gfx_button(int32_t button) { return api ? api->button(button) : 0; }
+int32_t simple_gfx_key(int32_t key) { return api ? api->key(key) : 0; }
+int32_t simple_gfx_close(void) { if (api) api->close(); return 0; }
+int32_t simple_gfx_wait(int64_t timeout) { return api ? api->wait(timeout) : -1; }
diff --git a/src/main/c/simple_graphics.h b/src/main/c/simple_graphics.h
new file mode 100644
index 00000000..370256be
--- /dev/null
+++ b/src/main/c/simple_graphics.h
@@ -0,0 +1,20 @@
+#ifndef SIMPLE_GRAPHICS_H
+#define SIMPLE_GRAPHICS_H
+#include <stdint.h>
+
+// Private, versioned boundary between the tiny runtime loader and MiniFB.
+// All calls run on the main thread. Pixel memory is borrowed for present only.
+struct simple_graphics_api {
+    int32_t version;
+    int32_t (*open)(const char *, uint32_t, uint32_t);
+    int32_t (*present)(const uint32_t *, uint32_t);
+    int32_t (*poll)(int32_t);
+    int32_t (*mouse_x)(void);
+    int32_t (*mouse_y)(void);
+    int32_t (*button)(int32_t);
+    int32_t (*key)(int32_t);
+    void (*close)(void);
+    int32_t (*wait)(int64_t);
+};
+#define SIMPLE_GRAPHICS_VERSION 2
+#endif
diff --git a/src/main/c/simple_miniaudio.c b/src/main/c/simple_miniaudio.c
new file mode 100644
index 00000000..03dbadd7
--- /dev/null
+++ b/src/main/c/simple_miniaudio.c
@@ -0,0 +1,123 @@
+#include "simple_audio.h"
+#define MA_NO_DECODING
+#define MA_NO_ENCODING
+#define MA_NO_RESOURCE_MANAGER
+#define MA_NO_NODE_GRAPH
+#define MA_NO_ENGINE
+#define MINIAUDIO_IMPLEMENTATION
+#include <miniaudio.h>
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#define RATE 48000
+#define SLOTS 32
+static ma_device device;
+static ma_mutex mutex;
+static int opened, active;
+static uint32_t cursor;
+static struct { int16_t *pcm; uint32_t count; } sounds[SLOTS];
+
+// Only native-owned immutable PCM is read on the audio thread. The lock covers
+// a bounded copy, never allocation, synthesis, device calls, or Simple code.
+static void output(ma_device *unused, void *out, const void *in, ma_uint32 frames) {
+    (void)unused; (void)in;
+    memset(out,0,frames*sizeof(int16_t));
+    ma_mutex_lock(&mutex);
+    if (active) {
+        uint32_t count=sounds[active].count-cursor;
+        if (count>frames) count=frames;
+        memcpy(out,sounds[active].pcm+cursor,count*sizeof(int16_t));
+        cursor+=count;
+        if (cursor==sounds[active].count) active=0;
+    }
+    ma_mutex_unlock(&mutex);
+}
+static int32_t load(const int16_t *pcm, uint32_t count) {
+    if (!opened || !pcm || !count || count>RATE*10) return -1;
+    int slot;
+    for (slot=4; slot<SLOTS && sounds[slot].pcm; ++slot) {}
+    if (slot==SLOTS) return -1;
+    int16_t *copy=malloc(count*sizeof(*copy));
+    if (!copy) return -1;
+    memcpy(copy,pcm,count*sizeof(*copy));
+    ma_mutex_lock(&mutex);
+    sounds[slot].pcm=copy; sounds[slot].count=count;
+    ma_mutex_unlock(&mutex);
+    return slot;
+}
+static int32_t play(int32_t sound) {
+    if (!opened || sound<=0 || sound>=SLOTS || !sounds[sound].pcm) return -1;
+    ma_mutex_lock(&mutex);
+    active=sound; cursor=0;
+    ma_mutex_unlock(&mutex);
+    return 0;
+}
+static int32_t stop(void) {
+    if (opened) { ma_mutex_lock(&mutex); active=0; ma_mutex_unlock(&mutex); }
+    return 0;
+}
+static int32_t playing(void) {
+    if (!opened) return 0;
+    ma_mutex_lock(&mutex);
+    int result=active!=0;
+    ma_mutex_unlock(&mutex);
+    return result;
+}
+static void close_audio(void) {
+    if (!opened) return;
+    ma_device_uninit(&device); // Joins callback before freeing buffers/mutex.
+    ma_mutex_uninit(&mutex);
+    for (int i=1;i<SLOTS;++i) {
+        free(sounds[i].pcm); sounds[i].pcm=NULL; sounds[i].count=0;
+    }
+    opened=0; active=0; cursor=0;
+}
+static int tone(int slot, int descending) {
+    uint32_t note=slot==1 ? RATE*7/100 : RATE*16/100;
+    int notes=slot==1 ? 1 : 3;
+    sounds[slot].count=note*notes;
+    sounds[slot].pcm=calloc(note*notes,sizeof(int16_t));
+    if (!sounds[slot].pcm) return -1;
+    const double pitches[3]={523.251,659.255,783.991};
+    for (int n=0;n<notes;++n) {
+        double hz=slot==1 ? 440.0 : pitches[descending ? 2-n : n];
+        for (uint32_t i=0;i<note;++i) {
+            double t=(double)i/note;
+            double envelope=sin(3.141592653589793*t);
+            sounds[slot].pcm[n*note+i]=(int16_t)(3200*envelope*envelope*sin(6.283185307179586*hz*i/RATE));
+        }
+    }
+    return 0;
+}
+static int32_t open_audio(void) {
+    if (opened) return 0;
+    if (ma_mutex_init(&mutex)!=MA_SUCCESS) return -1;
+    ma_device_config config=ma_device_config_init(ma_device_type_playback);
+    config.playback.format=ma_format_s16;
+    config.playback.channels=1;
+    config.sampleRate=RATE;
+    config.dataCallback=output;
+#ifdef SIMPLE_AUDIO_TEST_NULL
+    ma_backend backend=ma_backend_null;
+    ma_result result=ma_device_init_ex(&backend,1,NULL,&config,&device);
+#else
+    ma_result result=ma_device_init(NULL,&config,&device);
+#endif
+    if (result!=MA_SUCCESS) {
+        ma_mutex_uninit(&mutex);
+        fprintf(stderr,"Simple audio: no playback device (%d); continuing silently.\n",result);
+        return -1;
+    }
+    opened=1;
+    if (tone(1,0) || tone(2,0) || tone(3,1) || ma_device_start(&device)!=MA_SUCCESS) {
+        close_audio(); return -1;
+    }
+    return 0;
+}
+static const struct simple_audio_api api={SIMPLE_AUDIO_VERSION,open_audio,load,play,stop,playing,close_audio};
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+const struct simple_audio_api *simple_miniaudio_api(void) { return &api; }
diff --git a/src/main/c/simple_minifb.c b/src/main/c/simple_minifb.c
new file mode 100644
index 00000000..2117f0d2
--- /dev/null
+++ b/src/main/c/simple_minifb.c
@@ -0,0 +1,117 @@
+#include "simple_graphics.h"
+#include <MiniFB.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <errno.h>
+#include <time.h>
+#include <poll.h>
+#include "WindowData.h"
+#include "x11/WindowData_X11.h"
+#endif
+
+// One fixed-size window for now. No Simple pointer survives a native call:
+// MiniFB retains its last draw buffer for OS repaint events, so copy it here.
+static struct mfb_window *window;
+static uint32_t *frame;
+static uint32_t width, height;
+
+// The C-only build never installs the upstream C++ callback wrappers.
+void release_cpp_stub(struct mfb_window *unused) { (void)unused; }
+
+static void close_window(void) {
+    if (window) {
+        mfb_close(window);             // Requests close.
+        mfb_update_events(window);     // Actually destroys the window.
+        window = NULL;
+    }
+    free(frame);
+    frame = NULL;
+}
+
+static int32_t open_window(const char *title, uint32_t w, uint32_t h) {
+    if (window || !w || !h || w > UINT32_MAX / 4 ||
+        (uint64_t)w * h > UINT32_MAX || (uint64_t)w * h > SIZE_MAX / 4) {
+        fprintf(stderr, "Simple graphics: invalid dimensions or a window is already open.\n");
+        return -1;
+    }
+    frame = calloc((size_t)w * h, sizeof(*frame));
+    if (!frame) {
+        fprintf(stderr, "Simple graphics: cannot allocate the display buffer.\n");
+        return -1;
+    }
+    window = mfb_open(title, w, h);
+    if (!window) {
+        fprintf(stderr, "Simple graphics: MiniFB could not open a window (is a graphical display available?).\n");
+        close_window();
+        return -1;
+    }
+    width = w;
+    height = h;
+    return 0;
+}
+
+static int32_t status(mfb_update_state state) {
+    if (state == MFB_STATE_OK) return 0;
+    if (state == MFB_STATE_EXIT) {
+        window = NULL; // MiniFB has already destroyed it.
+        close_window();
+        return 1;
+    }
+    fprintf(stderr, "Simple graphics: MiniFB update failed (%d).\n", state);
+    close_window();
+    return -1;
+}
+
+static int32_t present(const uint32_t *pixels, uint32_t count) {
+    if (!window) return 1;
+    if (!pixels || count != (uint64_t)width * height) {
+        fprintf(stderr, "Simple graphics: pixel array length must equal width * height.\n");
+        return -1;
+    }
+    memcpy(frame, pixels, (size_t)count * sizeof(*frame));
+    return status(mfb_update_ex(window, frame, width, height));
+}
+
+static int32_t wait_events(int64_t timeout) {
+    if (!window) return 1;
+    if (timeout < -1) return -1;
+    // May return early; the game recomputes its deadlines after every wakeup.
+    int ms=timeout>INT_MAX ? INT_MAX : (int)timeout;
+#ifdef _WIN32
+    if (MsgWaitForMultipleObjectsEx(0,NULL,ms<0 ? INFINITE : (DWORD)ms,
+            QS_ALLINPUT,MWMO_INPUTAVAILABLE)==WAIT_FAILED) return -1;
+#else
+    // The pinned MiniFB X11 backend owns this connection. Check already queued
+    // Xlib events before waiting on its socket; no new event thread is needed.
+    SWindowData *data=(SWindowData *)window;
+    SWindowData_X11 *native=(SWindowData_X11 *)data->specific;
+    if (!XPending(native->display)) {
+        struct pollfd fd={ConnectionNumber(native->display),POLLIN,0};
+        if (poll(&fd,1,ms)<0 && errno!=EINTR) return -1;
+    }
+#endif
+    return status(mfb_update_events(window));
+}
+static int32_t poll_events(int32_t wait) { return wait_events(wait ? 17 : 0); }
+static int32_t mouse_x(void) { return window ? mfb_get_mouse_x(window) : 0; }
+static int32_t mouse_y(void) { return window ? mfb_get_mouse_y(window) : 0; }
+static int32_t button(int32_t b) {
+    return window && b >= 0 && b < 8 ? mfb_get_mouse_button_buffer(window)[b] != 0 : 0;
+}
+static int32_t key(int32_t k) {
+    return window && k >= 0 && k <= MFB_KB_KEY_LAST ? mfb_get_key_buffer(window)[k] != 0 : 0;
+}
+
+static const struct simple_graphics_api api = {
+    SIMPLE_GRAPHICS_VERSION, open_window, present, poll_events,
+    mouse_x, mouse_y, button, key, close_window, wait_events
+};
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+const struct simple_graphics_api *simple_minifb_api(void) { return &api; }
diff --git a/src/main/c/simple_time.c b/src/main/c/simple_time.c
new file mode 100644
index 00000000..2e579922
--- /dev/null
+++ b/src/main/c/simple_time.c
@@ -0,0 +1,61 @@
+#define _POSIX_C_SOURCE 200809L
+#include <time.h>
+#include <stdint.h>
+#include <errno.h>
+
+// Fixed-width bridge; no native struct layout or retained Simple pointers.
+static int64_t clock_value(clockid_t clock, int64_t scale) {
+    struct timespec t;
+    if (clock_gettime(clock,&t)) return -1;
+    if (t.tv_sec>INT64_MAX/scale || t.tv_sec<INT64_MIN/scale) {
+        errno=EOVERFLOW; return -1;
+    }
+    int64_t base=(int64_t)t.tv_sec*scale;
+    int64_t fraction=t.tv_nsec/(1000000000/scale);
+    if (base>INT64_MAX-fraction) { errno=EOVERFLOW; return -1; }
+    return base+fraction;
+}
+int64_t simple_time_now(void) { return clock_value(CLOCK_REALTIME,1000); }
+int64_t simple_time_mono(void) { return clock_value(CLOCK_MONOTONIC,1000); }
+int64_t simple_time_nano(void) { return clock_value(CLOCK_MONOTONIC,1000000000); }
+int32_t simple_time_sleep(int64_t ms, int32_t absolute) {
+    if (ms<0) { errno=EINVAL; return -1; }
+    struct timespec t={ms/1000,(ms%1000)*1000000};
+    int result;
+    if (!absolute) {
+        // Retry the remaining duration after signals; no busy waiting.
+        do { result=nanosleep(&t,&t); } while (result && errno==EINTR);
+        return result;
+    }
+    do { result=clock_nanosleep(CLOCK_MONOTONIC,TIMER_ABSTIME,&t,NULL); } while (result==EINTR);
+    if (result) { errno=result; return -1; }
+    return 0;
+}
+static int leap(int y) { return y%4==0 && (y%100!=0 || y%400==0); }
+static int local_fields(int64_t ms, struct tm *local, struct tm *utc) {
+    tzset();
+    int64_t sec=ms/1000;
+    if (ms%1000<0) --sec;
+    time_t t=(time_t)sec;
+    if ((int64_t)t!=sec || !localtime_r(&t,local) || !gmtime_r(&t,utc)) return -1;
+    if (local->tm_year < -1899 || local->tm_year > 8099) { errno=EOVERFLOW; return -1; }
+    return 0;
+}
+int32_t simple_time_local(int64_t ms, int64_t *out) {
+    struct tm t,u;
+    if (local_fields(ms,&t,&u)) return -1;
+    int days=t.tm_yday-u.tm_yday;
+    if (t.tm_year>u.tm_year) days+=365+leap(u.tm_year+1900);
+    if (t.tm_year<u.tm_year) days-=365+leap(t.tm_year+1900);
+    int offset=days*86400+(t.tm_hour-u.tm_hour)*3600+(t.tm_min-u.tm_min)*60+t.tm_sec-u.tm_sec;
+    out[0]=t.tm_year+1900; out[1]=t.tm_mon+1; out[2]=t.tm_mday;
+    out[3]=t.tm_hour; out[4]=t.tm_min; out[5]=t.tm_sec;
+    out[6]=(ms%1000+1000)%1000; out[7]=t.tm_wday;
+    out[8]=offset; out[9]=t.tm_isdst>0;
+    return 0;
+}
+int32_t simple_time_zone(int64_t ms, char *out, uint32_t capacity) {
+    struct tm t,u;
+    if (!capacity || local_fields(ms,&t,&u)) return -1;
+    return (int32_t)strftime(out,capacity,"%Z",&t);
+}
diff --git a/src/main/java/com/seaofnodes/simple/README.md b/src/main/java/com/seaofnodes/simple/README.md
index af86f21e..a8916aa8 100644
--- a/src/main/java/com/seaofnodes/simple/README.md
+++ b/src/main/java/com/seaofnodes/simple/README.md
@@ -2,7 +2,7 @@
 
 | Directory | Contents |
 | --- | --- |
-| `parser/` | Recursive-descent grammar routines, lexing, name resolution, and construction of the initial IR. `Var` describes a lexical binding. See the [grammar map](../../../../../../docs/chapter30/30-grammar.md). |
+| `parser/` | Recursive-descent grammar routines, lexing, name resolution, and construction of the initial IR. `Var` describes a lexical binding. See the [grammar map](../../../../../../docs/chapter31/31-grammar.md). |
 | `node/` | Sea-of-Nodes IR nodes: graph edges, type computation, and local peephole rewrites. |
 | `node/cpus/` | Machine-specific nodes and instruction selection support for `arm`, `riscv`, and `x86_64_v2`. |
 | `codegen/` | Compilation driver and passes: module loading, optimization, scheduling, register allocation, serialization, and machine-code emission. `IterPeeps` runs the peephole worklist. |
diff --git a/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java b/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
index b4c93e1e..8618b47b 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/CodeGen.java
@@ -786,7 +786,11 @@ public class CodeGen {
     public boolean _asmLittle=true;
     public String asm() { return asm(new SB()).toString(); }
     SB asm(SB sb) {
-        ASMPrinter.print(sb,this);
+        if( _encodings.isEmpty() ) ASMPrinter.print(sb,this);
+        else for( var entry : _encodings.entrySet() ) {
+            sb.p("\n=== Compilation unit: ").p(entry.getKey()._cname).p(" ===\n");
+            ASMPrinter.print(sb,this,entry.getValue());
+        }
         return sb;
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/codegen/ElfWriter.java b/src/main/java/com/seaofnodes/simple/codegen/ElfWriter.java
index fcf5c287..c5b25be0 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/ElfWriter.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/ElfWriter.java
@@ -318,11 +318,15 @@ public class ElfWriter {
         _strtab = new StringSection();
 
         // place all the symbols
+        Encoding enc = _code._encoding;
         int nlocals = 1/*null*/+9/*number of sections*/+1/*Simple section*/;
+        int debugLocals=0;
+        for( StaticData.ObjectData obj : enc._data.objects.values() )
+            if( !obj.external ) debugLocals+=obj.debugNames.size();
+        nlocals+=debugLocals;
         SymbolSection symbols = new SymbolSection(nlocals);
 
         // we've already constructed these entire sections in the encoding phase
-        Encoding enc = _code._encoding;
         // Append ELF-only thunks to a copy. Export must not change instruction
         // offsets or the image used by the in-memory linker and emulators.
         BAOS textBits = new BAOS(enc._bits.toByteArray(),enc._bits.size());
@@ -402,10 +406,17 @@ public class ElfWriter {
         SimpleSection simple = new SimpleSection(_code._serial);
 
         // Write the local section header symbols
-        assert nlocals == 1+_sections._len;
+        assert nlocals == 1+_sections._len+debugLocals;
         symbols.symbol("",0,0,0); // Null symbol at index 0
         for( Section s : _sections )
             symbols.symbol(s._name, s._index, SYM_BIND_LOCAL, SYM_TYPE_SECTION, 0, s.size());
+        // Local aliases describe the pooled object without changing linkage.
+        // Several source constants may name the same bytes.
+        for( StaticData.ObjectData obj : enc._data.objects.values() )
+            if( !obj.external )
+                for( String name : obj.debugNames )
+                    symbols.symbol(name,obj.readOnly ? rodata._index : rwdata._index,
+                                   SYM_BIND_LOCAL,SYM_TYPE_OBJECT,obj.offset,obj.size);
 
         int size = 64; // ELF header size
         // size of all section data
diff --git a/src/main/java/com/seaofnodes/simple/codegen/Encoding.java b/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
index b07a8fec..eb62c36a 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
@@ -39,7 +39,9 @@ public class Encoding implements com.seaofnodes.isa.CodeSink {
     public final BAOS _bits  = new BAOS(); // Instructions / encodings
     public final BAOS _cpool = new BAOS(); // Constant r/o pool
     public final BAOS _sdata = new BAOS(); // Static   r/w pool
-    public final HashMap<Node,Relo> _bigCons = new HashMap<>();
+    // Relocations belong to instruction occurrences, including equal constant
+    // loads cloned by scheduling/register allocation. Structural keys lose sites.
+    public final IdentityHashMap<Node,Relo> _bigCons = new IdentityHashMap<>();
     public final StaticData _data;
     public final HashMap<String,Integer> _externalAddresses = new HashMap<>();
 
@@ -157,7 +159,7 @@ public class Encoding implements com.seaofnodes.isa.CodeSink {
 
     // Nodes need "relocation" patching; things done after code is placed.
     // Record src and dst Nodes.
-    private final HashMap<Node,CFGNode> _internals = new HashMap<>();
+    private final IdentityHashMap<Node,CFGNode> _internals = new IdentityHashMap<>();
     // Source is a Call, destination in the Fun.
     public Encoding relo( CallNode call ) {
         FunNode fun = _code.link(call.tfp());
@@ -187,13 +189,13 @@ public class Encoding implements com.seaofnodes.isa.CodeSink {
     }
 
     // External references only located by Strings a link-time
-    public final HashMap<Node,String> _externals = new HashMap<>();
+    public final IdentityHashMap<Node,String> _externals = new IdentityHashMap<>();
     public Encoding external( Node n, String extern ) {
         _externals.put(n,extern);
         return this;
     }
 
-    public final HashMap<Node,String> _externData = new HashMap<>();
+    public final IdentityHashMap<Node,String> _externData = new IdentityHashMap<>();
     public void externalData(Node n, String name) { _externData.put(n,name); }
 
     // Store t as a 32/64 bit constant in the code space; generate RIP-relative
diff --git a/src/main/java/com/seaofnodes/simple/codegen/IterPeeps.java b/src/main/java/com/seaofnodes/simple/codegen/IterPeeps.java
index 985cd4d2..f4acb729 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/IterPeeps.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/IterPeeps.java
@@ -65,8 +65,10 @@ public class IterPeeps {
      * Iterate peepholes and inlining to a fixed point
      */
     public void iterate( CodeGen code ) {
+        assert !CodeGen.expensiveAssert(0) || (progressOnList(code, _work) && schedulableUses(code));
         boolean didInline = false;
         Ary<Node> defer = new Ary<>(Node.class);
+
         while( true ) {
             // Clean up everything that does not grow the code
             iteratePeeps(code);
@@ -97,8 +99,6 @@ public class IterPeeps {
 
     // Run all the code-reduction and type-lifting peeps as possible
     private void iteratePeeps( CodeGen code ) {
-        assert !CodeGen.expensiveAssert(0) || (progressOnList(code, _work) && schedulableUses(code));
-
         Node n;
         while( (n = _work.pop()) != null ) {
             if( n.isDead() )  continue;
diff --git a/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
index 3306ff8f..882a0f8a 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
@@ -150,7 +150,8 @@ public abstract class ParseAll {
     }
 
     private static void addRequiredTypes(CodeGen code, CompUnit cunit) {
-        for( String typeName : code.P._requiredTypes ) {
+        for( var required : code.P._requiredTypes.entrySet() ) {
+            String typeName = required.getKey();
             // A forward use can have been resolved later in this source file.
             if( Parser.TYPES.get(typeName) instanceof TypeStruct ts && !ts._fref ) continue;
             try {
@@ -158,7 +159,7 @@ public abstract class ParseAll {
                 if( xcunit != null )
                     cunit.addDep(xcunit);
                 else
-                    assert false : "expected to find required type";
+                    throw Parser.error("Unknown type '"+typeName+"'",required.getValue());
             } catch( IOException ioe ) {
                 throw new RuntimeException(ioe);
             }
diff --git a/src/main/java/com/seaofnodes/simple/codegen/RegAlloc.java b/src/main/java/com/seaofnodes/simple/codegen/RegAlloc.java
index 3991cd48..1b335c50 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/RegAlloc.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/RegAlloc.java
@@ -215,7 +215,7 @@ public class RegAlloc {
         _deferredLoopSelf.clear();
         for( byte round=0; !graphColor(round); round++ ) {
             split(round);
-            if( round >= 7 ) {
+            if( round >= 10 ) {
                 FunNode fun = _cfg.at(0).fun();
                 throw new IllegalStateException("Register allocation failed after eight rounds in "+
                                                 (fun==null ? "<root>" : fun.label()));
diff --git a/src/main/java/com/seaofnodes/simple/codegen/Serialize.java b/src/main/java/com/seaofnodes/simple/codegen/Serialize.java
index ae4ecb74..b168c4af 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/Serialize.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/Serialize.java
@@ -417,7 +417,7 @@ public class Serialize {
         assert elf._clz._name==strs[1/*skip null ptr*/];
         for( Type type : types )
             if( type instanceof TypeStruct ts )
-                Parser.TYPES.put(ts._name,ts);
+                installType(ts);
         for( Type type : types ) {
             if( !(type instanceof TypeStruct ts) || !TypeStruct.startsClzPrefix(ts._name) )
                 continue;
@@ -429,7 +429,7 @@ public class Serialize {
         elf._pubTypes = new TypeStruct[npubTypes];
         for( int i=0; i<npubTypes; i++ ) {
             TypeStruct ts = elf._pubTypes[i] = (TypeStruct)types[pubTypeIds[i]];
-            Parser.TYPES.put(ts._name,ts);
+            installType(ts);
         }
         elf._functions = new FunctionSummary[bais.packed4()];
         for( int i = 0; i<elf._functions.length; i++ ) {
@@ -444,6 +444,18 @@ public class Serialize {
         return elf._types = new TypeRead(types,strs,fileAliases,fileFidxs,fileRpcs);
     }
 
+    private static void installType(TypeStruct ts) {
+        // TYPES names the mutable array declaration. Read-only arrays in
+        // imported signatures keep their own types, but must not replace that
+        // declaration: closeOver looks up its mutable variant by name.
+        if( ts.isConAry() ) {
+            TypeConAry ary=(TypeConAry)ts.field("[]")._t;
+            ts=TypeStruct.makeAry(ts._name,TypeInteger.U32,ts.field("#")._alias,
+                ary.storageType(),ts.field("[]")._alias,false);
+        } else if( ts.isAry() ) ts = ts.replace(ts.field("[]").makeFrom(false));
+        Parser.TYPES.put(ts._name,ts);
+    }
+
     static void readAll( CodeGen code, ElfReader elf, GlobalBits aliases, GlobalBits fidxs, GlobalBits rpcs ) {
         BAOS bais = elf._bais;
         TypeRead tread = readTypes(code, elf, aliases, fidxs, rpcs);
diff --git a/src/main/java/com/seaofnodes/simple/codegen/StaticData.java b/src/main/java/com/seaofnodes/simple/codegen/StaticData.java
index 5d1a519b..3d3a40dd 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/StaticData.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/StaticData.java
@@ -14,7 +14,10 @@ public final class StaticData {
         public final String symbol;
         public final boolean readOnly, external;
         public final int alignment, size;
+        // Source names are aliases, not part of the object's pooling identity.
+        final TreeSet<String> debugNames = new TreeSet<>();
         public int offset;
+        public String label() { return debugNames.isEmpty() ? symbol : String.join(", ",debugNames); }
         ObjectData(Type t, String name, boolean ro, boolean ext) {
             type=t; symbol=name; readOnly=ro; external=ext;
             alignment=t.alignment();
@@ -73,7 +76,12 @@ public final class StaticData {
         // Register before following fields: class objects may refer to each other.
         if( !obj.external && t instanceof TypeStruct ts )
             for( Field f : ts._fields )
-                if( !f._extern && f._t.isConstant() ) target(f._t);
+                if( !f._extern && f._t.isConstant() ) {
+                    target(f._t);
+                    if( clz && f._final && f._t instanceof TypeMemPtr ptr &&
+                        pointerConstant(ptr) && !isClass(ptr._obj) )
+                        object(ptr._obj).debugNames.add(ts._name.substring(TypeStruct.CLZ.length())+"."+f._fname);
+                }
         return obj;
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/codegen/TypeCheck.java b/src/main/java/com/seaofnodes/simple/codegen/TypeCheck.java
index a86cd18a..418edaf6 100644
--- a/src/main/java/com/seaofnodes/simple/codegen/TypeCheck.java
+++ b/src/main/java/com/seaofnodes/simple/codegen/TypeCheck.java
@@ -21,12 +21,14 @@ abstract class TypeCheck {
         Ary<Node> errs = new Ary<>(Node.class);
         Ary<ConstructNode> constructs = new Ary<>(ConstructNode.class);
         Ary<InitViewNode> views = new Ary<>(InitViewNode.class);
+        Ary<ArrayInitNode> arrays = new Ary<>(ArrayInitNode.class);
         code._stop.walk( n -> {
                 if( n.err() != null )
                     errs.add(n);
                 if( n instanceof CLInitNode ) code.add(n);
                 if( n instanceof ConstructNode con ) constructs.add(con);
                 if( n instanceof InitViewNode view ) views.add(view);
+                if( n instanceof ArrayInitNode array ) arrays.add(array);
                 return null;
             });
 
@@ -57,13 +59,15 @@ abstract class TypeCheck {
             if( !con.isDead() ) con.subsume(con.in(1));
         for( InitViewNode view : views )
             if( !view.isDead() ) view.subsume(view.in(1));
+        for( ArrayInitNode array : arrays )
+            if( !array.isDead() ) array.subsume(array.in(2));
     }
 
     private static int errorRank(Node n) {
         // Bad memory access originates the error. Missing construction fields
         // in turn explain generic-scalar arithmetic further downstream.
         if( n instanceof MemOpNode && noBottomInputs(n) ) return 0;
-        if( n instanceof ConstructNode ) return 1;
+        if( n instanceof ConstructNode || n instanceof ArrayInitNode ) return 1;
         return noBottomInputs(n) ? 2 : 3;
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/ArrayInitNode.java b/src/main/java/com/seaofnodes/simple/node/ArrayInitNode.java
new file mode 100644
index 00000000..c6ae90ea
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/ArrayInitNode.java
@@ -0,0 +1,70 @@
+package com.seaofnodes.simple.node;
+
+import com.seaofnodes.print.ExprPrinter;
+import com.seaofnodes.simple.parser.Lexer;
+import com.seaofnodes.simple.parser.Parser;
+import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.Ary;
+
+/** Source checks for array construction and its yielded elements. Erased by
+ * TypeCheck before serialization and scheduling. */
+public final class ArrayInitNode extends Node {
+    private final int _count; // List size, -1 for a generator, -2 for a yielded element.
+    private final Lexer _loc;
+    public ArrayInitNode(Node ctrl, Node mem, Node ptr, Node len, int count, Lexer loc, Ary<Node> values) {
+        super(ctrl,mem,ptr,len);
+        _count=count; _loc=loc;
+        for( Node value : values ) addDef(value);
+    }
+    public ArrayInitNode(Node ctrl, Node value, Lexer loc) {
+        super(ctrl,null,value);
+        _count=-2; _loc=loc;
+    }
+    @Override public String label() { return "ArrayInit"; }
+    @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { return p.p("arrayInit(").n(in(2)).p(")"); }
+    @Override public Type compute() {
+        if( in(0)._type != Type.CONTROL ) return Type.TOP;
+        Type ptr = in(2)._type;
+        if( _count < 0 ) return ptr;
+        // A list is strict in all its inputs. Wait for every input before
+        // choosing a constant payload or falling to the ordinary array type.
+        // Otherwise one SCCP worklist order can return PtrTop (or an array)
+        // before another unresolved input sends the result back up to Top.
+        if( ptr.isHigh() || in(3)._type.isHigh() ) return Type.TOP;
+        for( int i = 4; i < nIns(); i++ )
+            if( in(i)._type.isHigh() ) return Type.TOP;
+        if( !(ptr instanceof TypeMemPtr tmp) ) return ptr;
+        Field body = tmp._obj.field("[]");
+        if( body == null || !body._final || !(body._t instanceof TypeInteger storage) ) return ptr;
+        if( !(in(3)._type instanceof TypeInteger length) || !length.isConstant() || length.value() != _count ) return ptr;
+        long[] values = new long[_count];
+        for( int i = 0; i < _count; i++ ) {
+            Type value = in(i+4)._type;
+            if( !(value instanceof TypeInteger integer) || !integer.isConstant() ) return ptr;
+            values[i] = integer.value();
+        }
+        TypeConAry contents = TypeConAry.make(storage,values);
+        TypeStruct array = TypeStruct.makeAry(tmp._obj._name,tmp._obj.field("#")._alias,body._alias,contents);
+        // The surrounding ReadOnlyNode supplies the public view. Keep this
+        // node's access flags consistent when its contents cease to be constant.
+        return TypeMemPtr.make((byte)2,array,true).withAccess(tmp._ro);
+    }
+    @Override public Node idealize() { return null; }
+    @Override public Parser.ParseException err() {
+        if( in(0)._type==Type.XCONTROL ) return null;
+        if( _count==-2 )
+            return TypeMemPtr.mayBePartial(in(2)._type)
+                ? Parser.error("Array initializer requires fully initialized elements",_loc) : null;
+        if( !(in(3)._type instanceof TypeInteger len) )
+            return Parser.error("Array length must be an integer",_loc);
+        if( len.isConstant() && (len.value()<0 || len.value()>TypeInteger.U32._max) )
+            return Parser.error("Array length is outside the u32 range",_loc);
+        if( _count>=0 && (!len.isConstant() || len.value()!=_count) )
+            return Parser.error("Array initializer has "+_count+" elements; length must equal that constant",_loc);
+        for( int i=4; i<nIns(); i++ )
+            if( TypeMemPtr.mayBePartial(in(i)._type) )
+                return Parser.error("Array initializer requires fully initialized elements",_loc);
+        return null;
+    }
+    @Override public boolean eq(Node n) { return this==n; }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/BulkMemPhiNode.java b/src/main/java/com/seaofnodes/simple/node/BulkMemPhiNode.java
index 130b631c..b49163e7 100644
--- a/src/main/java/com/seaofnodes/simple/node/BulkMemPhiNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/BulkMemPhiNode.java
@@ -261,15 +261,35 @@ public class BulkMemPhiNode extends PhiNode {
         mphi = new MemPhiNode(ScopeNode.memName(alias),alias);
         mphi.addDef(region());
         // Due to cycles, must set before calling peephole
-        // Splitting preserves the bulk Phi's established escape bound. Starting
-        // at BOT would temporarily invent escapes when the new slice is merged.
+        // An escaped slice must preserve the bulk Phi's established bound.
+        // An unescaped slice was excluded from that summary: include the
+        // facts hidden in predecessor slices before wiring any cyclic Phis.
         TypeMem old = (TypeMem)_type;
+        if( !XInt.bit(old._escAs,alias) )
+            old = (TypeMem)old.meet(sliceBound(this,alias,new BitSet()));
         mphi.setType(TypeMem.make(alias,old._t,old._one,old._clz,false,old._escFs,old._escAs));
         for( int i=1; i<nIns(); i++ )
             mphi.addDef(CodeGen.CODE.add(preciseInput(in(i),alias)));
         return CodeGen.CODE.add(mphi);
     }
 
+    // A bulk summary ignores unescaped slots in MemMerge inputs. Follow the
+    // same slots that splitting will expose, including across loop backedges.
+    // A visited cycle contributes TOP; its incoming definitions supply the bound.
+    private static TypeMem sliceBound(Node mem, int alias, BitSet visit) {
+        if( visit.get(mem._nid) ) return TypeMem.TOP;
+        visit.set(mem._nid);
+        if( mem instanceof MemMergeNode merge )
+            return sliceBound(merge.alias(alias),alias,visit);
+        if( mem instanceof BulkMemPhiNode bulk ) {
+            TypeMem bound = TypeMem.TOP;
+            for( int i = 1; i < bulk.nIns(); i++ )
+                bound = (TypeMem)bound.meet(sliceBound(bulk.in(i),alias,visit));
+            return bound;
+        }
+        return mem._type instanceof TypeMem bound ? bound : TypeMem.BOT;
+    }
+
     MemPhiNode _findPhi(int alias) {
         for( Node use : region().outs() )
             if( use instanceof MemPhiNode mphi && mphi._alias==alias )
diff --git a/src/main/java/com/seaofnodes/simple/node/CallEndNode.java b/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
index b5156c2d..108dd024 100644
--- a/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CallEndNode.java
@@ -85,6 +85,8 @@ public class CallEndNode extends CFGNode implements MultiNode {
             return ftype.isHigh() ? TypeTuple.STATE.dual() : TypeTuple.STATE;
         // Mid-fold, just take the inlined callee's return.
         if( _folding ) return in(1)._type;
+        TypeTuple intrinsic=Intrinsic.compute(call,this);
+        if( intrinsic!=null ) return intrinsic;
 
         // The outside continuation reads Start directly: Call can remain
         // CONTROL while its possible returned identities change.
@@ -135,6 +137,8 @@ public class CallEndNode extends CFGNode implements MultiNode {
     }
 
     public byte maybeInline() {
+        byte intrinsic=Intrinsic.tryInline(this);
+        if( intrinsic>0 ) return intrinsic;
         byte inline = inlineCandidate(false);
         if( CodeGen.CODE._midAssert )
             return inline;
diff --git a/src/main/java/com/seaofnodes/simple/node/CallNode.java b/src/main/java/com/seaofnodes/simple/node/CallNode.java
index ac5e4eee..9e9c5224 100644
--- a/src/main/java/com/seaofnodes/simple/node/CallNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/CallNode.java
@@ -97,6 +97,7 @@ public class CallNode extends CFGNode {
         if( _type!=Type.CONTROL ) return TypeMem.BOT;
         if( !(fptr()._type instanceof TypeFunPtr) )
             return fptr()._type.isHigh() ? TypeMem.START : TypeMem.BOT;
+        if( Intrinsic.pure(this) ) return TypeMem.START;
         if( !external() ) return TypeMem.START;
         Type input = dep.addDepForwards(mem())._type;
         TypeMem escaped = input instanceof TypeMem m ? m : input.isHigh() ? TypeMem.TOP : TypeMem.BOT;
@@ -241,6 +242,8 @@ public class CallNode extends CFGNode {
             return Parser.error("Expected a function, but found " + fptr()._type, _loc);
         if( !tfp.notNull() )
             return Parser.error( "Might be null calling "+tfp, _loc);
+        Parser.ParseException intrinsic=Intrinsic.err(this);
+        if( intrinsic!=null ) return intrinsic;
         if( nargs() != tfp.nargs() )
             return Parser.error( "Expecting "+(tfp.nargs()-1)+" arguments, but found "+(nargs()-1), _loc);
 
@@ -253,6 +256,15 @@ public class CallNode extends CFGNode {
                 // Constructors return private memory and carry hidden self and
                 // selfMem arguments ahead of the source-level arguments.
                 int argno = i - (tfp.ret() instanceof TypeMem ? 2 : 0);
+                // Access qualifiers are not shown by the structural type dump.
+                // Report the differing permission instead of two huge shapes.
+                if( arg(i+2)._type instanceof TypeMemPtr actual && actual._ro &&
+                    tfp.arg(i) instanceof TypeMemPtr formal && !formal._ro ) {
+                    String who = i == 0 ? name() == null ? "Receiver" : "Receiver for method '"+name()+"'"
+                                        : "Argument #"+argno;
+                    return Parser.error(who+" is read-only "+actual._obj.str()+
+                                        "; expected writable "+formal._obj.str(),_loc);
+                }
                 return Parser.error( "Argument #" + argno + " isa " + arg(i+2)._type + ", but must be a " + tfp.arg(i), _loc );
             }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/EscapeNode.java b/src/main/java/com/seaofnodes/simple/node/EscapeNode.java
index 57340609..a8a6151c 100644
--- a/src/main/java/com/seaofnodes/simple/node/EscapeNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/EscapeNode.java
@@ -64,6 +64,10 @@ public class EscapeNode extends TypeNode {
 
     @Override
     public Type compute() {
+        // A static constant array has no private heap writes to publish.
+        // This depends on its type, regardless of which node produced it.
+        if( self()!=null && self()._type instanceof TypeMemPtr ptr &&
+            ptr.isConstant() && ptr._obj.isConAry() ) return pub()._type;
         if( priv()._type.isHigh() ) return TypeMem.TOP;
         if( pub ()._type.isHigh() ) return TypeMem.TOP;
         TypeMem mpriv = (TypeMem)priv()._type;
@@ -100,6 +104,8 @@ public class EscapeNode extends TypeNode {
     }
 
     @Override public Node idealize() {
+        if( self()._type instanceof TypeMemPtr ptr && ptr.isConstant() && ptr._obj.isConAry() )
+            return pub();
         // Sharpen private memory input
         if( priv() instanceof MemMergeNode mmm ) {
             setDef(2,mmm.alias(fld()._alias));
diff --git a/src/main/java/com/seaofnodes/simple/node/Intrinsic.java b/src/main/java/com/seaofnodes/simple/node/Intrinsic.java
new file mode 100644
index 00000000..82626507
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/Intrinsic.java
@@ -0,0 +1,119 @@
+package com.seaofnodes.simple.node;
+
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.parser.Parser;
+import com.seaofnodes.simple.type.*;
+
+// Fixed-semantics C functions. Recognition, effects and expansion live here;
+// Call/CallEnd only delegate. These symbols also have ordinary C definitions
+// for calls whose target is not known at compile time.
+public final class Intrinsic {
+    private Intrinsic() {}
+
+    private enum Op {
+        F64_BITS("simple_f64_bits",TypeFloat.F64,TypeInteger.BOT,true),
+        F64_FROM_BITS("simple_f64_from_bits",TypeInteger.BOT,TypeFloat.F64,true);
+
+        final String symbol;
+        final Type arg, ret;
+        final boolean pure;
+        Op(String symbol, Type arg, Type ret, boolean pure) {
+            this.symbol=symbol; this.arg=arg; this.ret=ret; this.pure=pure;
+        }
+        boolean signature(TypeFunPtr fp) {
+            // Slot zero is the implicit receiver, omitted by the C ABI.
+            return fp.nargs()==2 && fp.arg(1)==arg && fp.ret()==ret;
+        }
+        Expansion expand(CallNode call) {
+            Node value=switch(this) {
+            case F64_BITS -> new F64BitsNode(call.arg(3)).peephole();
+            case F64_FROM_BITS -> new F64FromBitsNode(call.arg(3)).peephole();
+            };
+            return new Expansion(call.ctrl(),call.mem(),value);
+        }
+    }
+
+    private static Op lookup(CallNode call) {
+        if( !(call.fptr()._type instanceof TypeFunPtr fp) || !fp.notNull() || !fp.isConstant() ) return null;
+        String symbol=CodeGen.CODE.externFunc(fp.fidx());
+        if( symbol==null ) return null; // A Simple function with this name is ordinary code.
+        for( Op op : Op.values() ) if( op.symbol.equals(symbol) ) return op;
+        return null;
+    }
+
+    public static Parser.ParseException err(CallNode call) {
+        Op op=lookup(call);
+        return op==null || op.signature(call.tfp()) ? null : Parser.error(
+            "Intrinsic '"+op.symbol+"' requires { "+op.arg.str()+" -> "+op.ret.str()+" }",call._loc);
+    }
+
+    // Both initial operations are pure and expose no references. Future atomic
+    // operations need their own memory/escape semantics, not this passthrough.
+    public static boolean pure(CallNode call) {
+        Op op=lookup(call);
+        return op!=null && op.pure && op.signature(call.tfp());
+    }
+
+    public static TypeTuple compute(CallNode call, Node dep) {
+        if( !pure(call) ) return null;
+        return TypeTuple.make(Type.CONTROL,dep.addDep(call.mem())._type,call.tfp().ret());
+    }
+
+    // An expansion replaces the complete call state, even for a pure value op.
+    private record Expansion(Node control, Node memory, Node value) {
+        void replace(CallEndNode end) {
+            Node[] state={control,memory,value};
+            for( Node n : state ) n.keep();
+            end.keep();
+            for( Node use : end._outputs.asAry() ) {
+                if( use==null ) continue; // Our temporary keep.
+                assert use instanceof Proj;
+                use.subsume(state[((Proj)use).idx()]);
+            }
+            end.unkill();
+            for( Node n : state ) n.unkill();
+            CodeGen.CODE.invalidateIDepthCaches();
+        }
+    }
+
+    // Same cheap-inlining worklist as ordinary functions, but no body/Return,
+    // cloning, size heuristic, or import loading is needed.
+    public static byte tryInline(CallEndNode end) {
+        if( end.folding() || !(end.in(0) instanceof CallNode call) ) return 0;
+        Op op=lookup(call);
+        if( op==null || !op.signature(call.tfp()) || call.nargs()!=call.tfp().nargs() ||
+            !end.goodArgs(call,call.tfp()) ) return 0;
+        if( !CodeGen.CODE._midAssert ) op.expand(call).replace(end);
+        return 1;
+    }
+
+    public abstract static class BitCastNode extends Node {
+        BitCastNode(Node value) { super(null,value); }
+        public abstract boolean toBits();
+        @Override public Type compute() {
+            Type input=in(1)._type;
+            Type result=toBits() ? TypeInteger.BOT : TypeFloat.F64;
+            if( input.isHigh() ) return result.dual();
+            if( toBits() && input instanceof TypeFloat f && f.isConstant() )
+                return TypeInteger.constant(Double.doubleToRawLongBits(f.value()));
+            if( !toBits() && input instanceof TypeInteger i && i.isConstant() )
+                return TypeFloat.constant(Double.longBitsToDouble(i.value()));
+            return result;
+        }
+        @Override public Node idealize() {
+            return in(1) instanceof BitCastNode cast && cast.toBits()!=toBits() ? cast.in(1) : null;
+        }
+    }
+    public static final class F64BitsNode extends BitCastNode {
+        public F64BitsNode(Node value) { super(value); }
+        @Override public boolean toBits() { return true; }
+        @Override public Tag serialTag() { return Tag.F64Bits; }
+        @Override protected String format() { return "f64Bits(%1)"; }
+    }
+    public static final class F64FromBitsNode extends BitCastNode {
+        public F64FromBitsNode(Node value) { super(value); }
+        @Override public boolean toBits() { return false; }
+        @Override public Tag serialTag() { return Tag.F64FromBits; }
+        @Override protected String format() { return "f64FromBits(%1)"; }
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/src/main/java/com/seaofnodes/simple/node/LoadNode.java
index eb78ed1f..14efa315 100644
--- a/src/main/java/com/seaofnodes/simple/node/LoadNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/LoadNode.java
@@ -98,7 +98,15 @@ public class LoadNode extends MemOpNode {
             t = mem._alias==_alias ? mem._t : actual==null ? TypeScalar.BOT : actual._t;
         } else if( mem._alias==_alias )
             t = t.join(mem._t);
-        if( !mem._one ) t = mem.outside(t);
+        // A final method's identity comes from its declaration, not from an
+        // unknown outside writer. It remains callable on a local object even
+        // when that function has never escaped to outside code.
+        if( !mem._one ) {
+            Type declared = Parser.TYPES.get(tmp._obj._name);
+            Field field = declared instanceof TypeStruct obj ? obj.field(_name) : null;
+            if( !(field != null && field._final && field._t instanceof TypeFunPtr fun && fun.isConstant()) )
+                t = mem.outside(t);
+        }
         // Store forwarding is also a value fact during SCCP. Waiting for the
         // later rewrite can turn a known non-null stored pointer into a
         // nullable declaration, then BOTTOM at the next dereference.
@@ -364,15 +372,13 @@ public class LoadNode extends MemOpNode {
         if( ptr instanceof PhiNode pphi && pphi.region() == r )
             return true;
 
-        // No, so can we lift this ptr?
-        CFGNode cptr = ptr.cfg0();
-        if( cptr != null )
-            // Pointer is controlled high
-            // TODO: Really needs to be the LCA of all inputs is high
-            return cptr.idepth() <= r.idepth();
-
-        // Dunno without a longer walk
-        return false;
+        // Each copied Load needs its pointer before the Region, including
+        // a loop's entry arm. input 0 alone misses floating Loads whose own
+        // pointer was produced inside the loop.
+        CFGNode pinned = ptr.cfg0();
+        if( pinned==null || pinned.idepth()>r.idepth() ) return false;
+        CFGNode cptr = ptr instanceof PhiNode phi ? phi.region() : CFGNode.earlyCFG(ptr);
+        return cptr==null || cptr.dominates(r.idom(memphi),memphi);
     }
 
     @Override public Parser.ParseException err() {
diff --git a/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java b/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
index aa3f6d57..19420839 100644
--- a/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MemMergeNode.java
@@ -20,8 +20,20 @@ public class MemMergeNode extends Node {
     public MemMergeNode( Node ...nodes) { super(nodes); _type = TypeMem.BOT; }
     public MemMergeNode(MemMergeNode mem) { super(mem); }
     @Override public Tag serialTag() { return Tag.MemMerge; }
-    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) { baos.packed1(nIns()); }
-    static Node make( BAOS bais )  { Node mem = new MemMergeNode(); mem.setDefX(bais.packed1()-1,null); return mem; }
+    public void packed( BAOS baos, HashMap<String,Integer> strs, HashMap<Type,Integer> types, IdentityHashMap<Node, Integer> anodes ) {
+        // A memory merge always has inputs. Zero escapes a wide alias table,
+        // preserving every existing nonzero single-byte count.
+        assert nIns()>0;
+        baos.packed1(nIns()<=255 ? nIns() : 0);
+        if( nIns()>255 ) baos.packed4(nIns());
+    }
+    static Node make( BAOS bais ) {
+        int count=bais.packed1();
+        if( count==0 ) count=bais.packed4();
+        Node mem=new MemMergeNode();
+        mem.setDefX(count-1,null);
+        return mem;
+    }
 
     @Override public String label() { return "ALLMEM"; }
     @Override public boolean isMem() { return true; }
diff --git a/src/main/java/com/seaofnodes/simple/node/MemOpNode.java b/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
index 35183380..bce11b50 100644
--- a/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/MemOpNode.java
@@ -94,7 +94,8 @@ public abstract class MemOpNode extends TypeNode {
         if( !(ptr()._type instanceof TypeMemPtr tmp) )
             return Type.BOTTOM;
         Field fld = tmp._obj.field(_name);
-        return fld == null || fld._t == null ? Type.BOTTOM : fld._t;
+        return fld == null || fld._t == null ? Type.BOTTOM :
+            fld._t instanceof TypeConAry ary ? ary.storageType() : fld._t;
     }
 
     @Override protected ExprPrinter<Node> _print1(ExprPrinter<Node> p) { return _printMach(p);  }
diff --git a/src/main/java/com/seaofnodes/simple/node/Node.java b/src/main/java/com/seaofnodes/simple/node/Node.java
index 2815dfba..d4c0794c 100644
--- a/src/main/java/com/seaofnodes/simple/node/Node.java
+++ b/src/main/java/com/seaofnodes/simple/node/Node.java
@@ -77,7 +77,7 @@ public abstract class Node extends BaseNode<Node> implements Cloneable {
         New,Never,Not,Or,Parm,Phi,Proj,PtrToInt,
         ReadOnly,Return,Region,RoundF32,
         Sar,Shl,Shr,Start,StartCU,StopCU,Stop,Store,Sub,
-        ToInteger,ToFloat,XCtrl,Xor;
+        ToInteger,ToFloat,XCtrl,Xor,F64Bits,F64FromBits;
         public static final Tag[] VALS = values();
         public Node make( BAOS bais, String[] strs, Type[] types, GlobalBits fileAliases, GlobalBits aliases ) {
             return switch(this) {
@@ -103,6 +103,8 @@ public abstract class Node extends BaseNode<Node> implements Cloneable {
             case Sub    -> new   SubNode(null,null,(byte)bais.packed1());
             case ToFloat-> new ToFloatNode(null);
             case ToInteger-> new ToIntegerNode(null);
+            case F64Bits-> new Intrinsic.F64BitsNode(null);
+            case F64FromBits-> new Intrinsic.F64FromBitsNode(null);
             case XCtrl  -> new XCtrlNode();
             case Xor    -> { int mode=bais.packed1(); assert mode==1; yield new XorNode(null,null,null); }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/StoreNode.java b/src/main/java/com/seaofnodes/simple/node/StoreNode.java
index 010d5f61..204e0c4b 100644
--- a/src/main/java/com/seaofnodes/simple/node/StoreNode.java
+++ b/src/main/java/com/seaofnodes/simple/node/StoreNode.java
@@ -243,6 +243,10 @@ public class StoreNode extends MemOpNode {
     private byte storageType() {
         if( !(ptr()._type instanceof TypeMemPtr tmp) )
             return 0;
+        // Completing a forward declaration changes TYPES without changing
+        // this Store's inputs. Wait for the pointer's type upgrade, which
+        // queues its users, before consulting the completed declaration.
+        if( tmp._obj._fref ) return 0;
         TypeStruct obj = (TypeStruct)Parser.TYPES.get(tmp._obj._name);
         Field fld = obj.field(_name);
         if( fld == null || fld._t == null )
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/arm/BitCastARM.java b/src/main/java/com/seaofnodes/simple/node/cpus/arm/BitCastARM.java
new file mode 100644
index 00000000..ec57b3f8
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/arm/BitCastARM.java
@@ -0,0 +1,23 @@
+package com.seaofnodes.simple.node.cpus.arm;
+
+import com.seaofnodes.isa.Arm64;
+import com.seaofnodes.simple.codegen.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.util.SB;
+
+// A representation move, with no arithmetic, rounding, or flag changes.
+public class BitCastARM extends MachConcreteNode implements MachNode {
+    private final boolean _toBits;
+    BitCastARM(Intrinsic.BitCastNode cast) { super(cast); _toBits=cast.toBits(); }
+    @Override public String op() { return _toBits ? "f64bits" : "f64frombits"; }
+    @Override public RegMask regmap(int i) { assert i==1; return _toBits ? arm.DMASK : arm.RMASK; }
+    @Override public RegMask outregmap() { return _toBits ? arm.WMASK : arm.DMASK; }
+    @Override public void encoding(Encoding enc) {
+        enc.add4(Arm64.f_mov_general(Arm64.OP_FMOV,0b01,0,_toBits ? 0b110 : 0b111,
+            enc.reg(in(1))-(_toBits ? arm.D_OFFSET : 0),
+            enc.reg(this)-(_toBits ? 0 : arm.D_OFFSET)));
+    }
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = bits ").p(code.reg(in(1)));
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java b/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
index ee7b0fc3..2d47edf5 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/arm/arm.java
@@ -350,6 +350,7 @@ public class arm extends Machine {
         case StoreNode st    -> st(st);
         case SubNode sub     -> sub.mode()==2 ? new SubFARM(sub) : sub(sub);
         case ToFloatNode tfn -> new I2F8ARM(tfn);
+        case Intrinsic.BitCastNode cast -> new BitCastARM(cast);
         case ToIntegerNode cvt -> new F8ToIARM(cvt);
         case XorNode xor     -> xor(xor);
 
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/riscv/BitCastRISC.java b/src/main/java/com/seaofnodes/simple/node/cpus/riscv/BitCastRISC.java
new file mode 100644
index 00000000..141ff7d5
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/riscv/BitCastRISC.java
@@ -0,0 +1,23 @@
+package com.seaofnodes.simple.node.cpus.riscv;
+
+import com.seaofnodes.isa.RiscV;
+import com.seaofnodes.simple.codegen.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.util.SB;
+
+// A representation move, with no arithmetic, rounding, or flag changes.
+public class BitCastRISC extends MachConcreteNode implements MachNode {
+    private final boolean _toBits;
+    BitCastRISC(Intrinsic.BitCastNode cast) { super(cast); _toBits=cast.toBits(); }
+    @Override public String op() { return _toBits ? "f64bits" : "f64frombits"; }
+    @Override public RegMask regmap(int i) { assert i==1; return _toBits ? riscv.FMASK : riscv.RMASK; }
+    @Override public RegMask outregmap() { return _toBits ? riscv.WMASK : riscv.FMASK; }
+    @Override public void encoding(Encoding enc) {
+        enc.add4(RiscV.r_type(RiscV.OP_FP,
+            enc.reg(this)-(_toBits ? 0 : riscv.F_OFFSET),0,
+            enc.reg(in(1))-(_toBits ? riscv.F_OFFSET : 0),0,_toBits ? 0b1110001 : 0b1111001));
+    }
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = bits ").p(code.reg(in(1)));
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SplitRISC.java b/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SplitRISC.java
index d455337b..de754393 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SplitRISC.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/riscv/SplitRISC.java
@@ -47,7 +47,7 @@ public class SplitRISC extends SplitNode {
             // FPR->FPR
             src -= riscv.F_OFFSET;
             dst -= riscv.F_OFFSET;
-            enc.add4(RiscV.r_type(RiscV.OP_FP, dst, 0b000, src, src, 0b0010101)); // dst = FMIN(src,src)
+            enc.add4(RiscV.r_type(RiscV.OP_FP, dst, 0b000, src, src, 0b0010001)); // FSGNJ.D preserves NaN bits.
         } else if(!srcX && dstX) {
             //GPR->FPR
             // fmv.d.x
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/riscv/riscv.java b/src/main/java/com/seaofnodes/simple/node/cpus/riscv/riscv.java
index 378955a5..976d1a52 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/riscv/riscv.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/riscv/riscv.java
@@ -254,6 +254,7 @@ public class riscv extends Machine {
         case StoreNode     st -> st(st);
         case SubNode      sub -> sub.mode()==2 ? new SubFRISC(sub) : sub(sub);
         case ToFloatNode  tfn -> i2f8(tfn);
+        case Intrinsic.BitCastNode cast -> new BitCastRISC(cast);
         case ToIntegerNode cvt -> new F8ToIRISC(cvt);
         case XorNode      xor -> xor(xor);
 
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/BitCastX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/BitCastX86.java
new file mode 100644
index 00000000..bf550032
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/BitCastX86.java
@@ -0,0 +1,23 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.isa.X86;
+import com.seaofnodes.simple.codegen.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.util.SB;
+
+// A representation move, with no arithmetic, rounding, or flag changes.
+public class BitCastX86 extends MachConcreteNode implements MachNode {
+    private final boolean _toBits;
+    BitCastX86(Intrinsic.BitCastNode cast) { super(cast); _toBits=cast.toBits(); }
+    @Override public String op() { return _toBits ? "f64bits" : "f64frombits"; }
+    @Override public RegMask regmap(int i) { assert i==1; return _toBits ? x86_64_v2.XMASK : x86_64_v2.RMASK; }
+    @Override public RegMask outregmap() { return _toBits ? x86_64_v2.WMASK : x86_64_v2.XMASK; }
+    @Override public void encoding(Encoding enc) {
+        X86.move(enc,!_toBits,_toBits,
+            enc.reg(this)-(_toBits ? 0 : x86_64_v2.XMM_OFFSET),
+            enc.reg(in(1))-(_toBits ? x86_64_v2.XMM_OFFSET : 0));
+    }
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" = bits ").p(code.reg(in(1)));
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
index 10cee059..ae725659 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/JmpX86.java
@@ -9,6 +9,7 @@ import com.seaofnodes.simple.util.Utils;
 // Jump on flags, uses flags
 public class JmpX86 extends IfNode implements MachNode, RIPRelSize {
     String _bop;
+    boolean _unsigned, _floating, _unorderedTaken;
     JmpX86( IfNode iff, String bop ) {
         super(iff);
         _bop = bop;
@@ -23,29 +24,47 @@ public class JmpX86 extends IfNode implements MachNode, RIPRelSize {
         if( set instanceof SetX86 setx && (cmp instanceof CmpX86 || cmp instanceof CmpIX86 || cmp instanceof CmpMemX86 || cmp instanceof CmpFX86) ) {
             _inputs.set( 1, cmp );
             _bop = setx._bop;
+            _unsigned = setx._unsigned;
+            _floating = cmp instanceof CmpFX86;
+            _unorderedTaken = _bop.equals("!=");
         } else
             throw Utils.TODO();
     }
     @Override public RegMask regmap(int i) { assert i==1; return x86_64_v2.FLAGS_MASK; }
     @Override public RegMask outregmap() { return null; }
-    @Override public void negate() { _bop = negate(_bop);  }
+    @Override public void negate() {
+        _bop = negate(_bop);
+        if( _floating ) _unorderedTaken = !_unorderedTaken;
+    }
+
+    private int condition() { return x86_64_v2.jumpop(_bop,_unsigned)&15; }
 
     @Override public void encoding( Encoding enc ) {
         if( in(1)==null && _bop=="!=" ) return;
-        X86.branch(enc,in(1)==null ? -1 : x86_64_v2.jumpop(_bop)&15);
+        // UCOMISD sets CF/ZF/PF, not signed-integer SF/OF. Handle unordered
+        // separately, including when layout has negated the original test.
+        if( _floating ) {
+            if( _unorderedTaken ) enc.add1(0x0F).add1(0x8A).add4(0); // JP target
+            else enc.add1(0x7A).add1(0); // JP past the ordered jump
+        }
+        X86.branch(enc,in(1)==null ? -1 : condition());
         enc.jump(this,cproj(0));
     }
 
     // Delta is from opcode start, but X86 measures from the end of the 2-byte encoding
     @Override public byte encSize(int delta) {
         if( in(1)==null && _bop=="!=" ) return 0;
-        return X86.branchSize(delta,in(1)!=null);
+        int prefix = !_floating ? 0 : _unorderedTaken ? 6 : 2;
+        return (byte)(prefix + X86.branchSize(delta-prefix,in(1)!=null));
     }
 
     // Delta is from opcode start
     @Override public void patch( Encoding enc, int opStart, int opLen, int delta ) {
         assert !(in(1)==null && _bop=="!=");
-        X86.patchBranch(enc.bits(),opStart,opLen,delta,in(1)==null ? -1 : x86_64_v2.jumpop(_bop)&15);
+        int prefix = !_floating ? 0 : _unorderedTaken ? 6 : 2;
+        if( _floating )
+            X86.patchBranch(enc.bits(),opStart,prefix,_unorderedTaken ? delta : opLen,10);
+        X86.patchBranch(enc.bits(),opStart+prefix,opLen-prefix,delta-prefix,in(1)==null ? -1 : condition());
     }
 
     @Override public void asm(CodeGen code, SB sb) {
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
index fcca7f8f..b0ecd685 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
@@ -67,9 +67,9 @@ public abstract class MemOpX86 extends MemOpNode implements MachNode {
         if( i==1 ) return null;               // Memory
         if( i==2 ) return x86_64_v2.RMASK;    // base  in GPR
         if( i==3 ) return x86_64_v2.RMASK;    // index in GPR
-        if( i==4 ) return _sz >= '4'
-                       ? x86_64_v2.MEM_MASK   // value in GPR or XMM
-                       : x86_64_v2.RMASK;     // Bytes and shorts in GPR only
+        // Integer arithmetic and comparisons require a GPR value operand.
+        // Only StoreX86 has alternate encodings that accept XMM values.
+        if( i==4 ) return x86_64_v2.RMASK;
         return null; // Anti-dependence
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NegFX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NegFX86.java
new file mode 100644
index 00000000..61662fd2
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NegFX86.java
@@ -0,0 +1,25 @@
+package com.seaofnodes.simple.node.cpus.x86_64_v2;
+
+import com.seaofnodes.isa.X86;
+import com.seaofnodes.simple.codegen.*;
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.type.TypeFloat;
+import com.seaofnodes.simple.util.SB;
+
+// Flip the sign bit, preserving signed zero, infinities, and NaN payloads.
+public class NegFX86 extends MachConcreteNode implements MachNode {
+    NegFX86(MinusNode neg) {
+        super(neg);
+        addDef(new FltX86(new ConstantNode(TypeFloat.constant(-0.0)),null));
+    }
+    @Override public String op() { return "negf"; }
+    @Override public RegMask regmap(int i) { assert i==1 || i==2; return x86_64_v2.XMASK; }
+    @Override public RegMask outregmap() { return x86_64_v2.XMASK; }
+    @Override public int twoAddress() { return 1; }
+    @Override public void encoding(Encoding enc) {
+        X86.sse(enc,0x66,0x0F57,false,enc.reg(this)-x86_64_v2.XMM_OFFSET,enc.reg(in(2))-x86_64_v2.XMM_OFFSET);
+    }
+    @Override public void asm(CodeGen code, SB sb) {
+        sb.p(code.reg(this)).p(" ^= ").p(code.reg(in(2))).p(" // sign bit");
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NegX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NegX86.java
index 86610f6d..4494985d 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NegX86.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NegX86.java
@@ -9,7 +9,7 @@ public class NegX86 extends MachConcreteNode implements MachNode {
     NegX86(MinusNode not) { super(not); }
     @Override public String op() { return "neg"; }
     @Override public RegMask regmap(int i) { return x86_64_v2.RMASK; }
-    @Override public RegMask outregmap()   { return x86_64_v2.RMASK; }
+    @Override public RegMask outregmap()   { return x86_64_v2.WMASK; }
     @Override public RegMask killmap()     { return x86_64_v2.FLAGS_MASK; }
     @Override public int twoAddress() { return 1; }
 
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NotX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NotX86.java
index 1e4e7c26..1291cf78 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NotX86.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/NotX86.java
@@ -9,7 +9,7 @@ public class NotX86 extends MachConcreteNode implements MachNode {
     NotX86(NotNode not) { super(not); }
     @Override public String op() { return "not"; }
     @Override public RegMask regmap(int i) { return x86_64_v2.RMASK; }
-    @Override public RegMask outregmap() { return x86_64_v2.RMASK;  }
+    @Override public RegMask outregmap() { return x86_64_v2.WMASK;  }
     @Override public RegMask killmap() { return x86_64_v2.FLAGS_MASK; }
 
     @Override public void encoding( Encoding enc ) {
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
index 864c1b55..bcc4880b 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/SetX86.java
@@ -4,7 +4,6 @@ import com.seaofnodes.isa.X86;
 import com.seaofnodes.simple.codegen.*;
 import com.seaofnodes.simple.node.*;
 import com.seaofnodes.simple.util.SB;
-import com.seaofnodes.simple.util.Utils;
 
 // Corresponds to the x86 instruction "sete && setne".
 // Use result of comparison without jump.
@@ -25,15 +24,14 @@ public class SetX86 extends MachConcreteNode implements MachNode {
     @Override public RegMask outregmap() { return x86_64_v2.WMASK; }
 
     @Override public void encoding( Encoding enc ) {
-        int op=switch (_bop) {
-            case "==" -> 0x94;  // SETE
-            case "<"  -> _unsigned ? 0x92 : 0x9C;  // SETB /SETL
-            case "<=" -> _unsigned ? 0x96 : 0x9E;  // SETBE/SETLE
-            case ">=" -> _unsigned ? 0x93 : 0x9D;  // SETAE/SETGE
-            case ">"  -> _unsigned ? 0x97 : 0x9F;  // SETA /SETG
-            default -> throw Utils.TODO();
-            };
-        X86.set(enc,op&15,enc.reg(this));
+        int dst=enc.reg(this);
+        if( in(1) instanceof CmpFX86 ) {
+            // MOV preserves comparison flags; unordered is true only for !=.
+            X86.unary(enc,0xC7,0,dst);
+            enc.add4(_bop.equals("!=") ? 1 : 0);
+            enc.add1(0x7A).add1(dst>=4 ? 8 : 6); // JP past SETcc/MOVZX
+        }
+        X86.set(enc,x86_64_v2.jumpop(_bop,_unsigned)&15,dst);
     }
 
     @Override public void asm(CodeGen code, SB sb) {
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/StoreX86.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/StoreX86.java
index 9ffa25fc..8dfd31e7 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/StoreX86.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/StoreX86.java
@@ -25,6 +25,9 @@ public class StoreX86 extends MemOpX86 {
     }
     // Register mask allowed as a result.  0 for no register.
     @Override public RegMask outregmap() { return null; }
+    @Override public RegMask regmap(int i) {
+        return i==4 && _sz>='4' ? x86_64_v2.MEM_MASK : super.regmap(i);
+    }
     @Override public void encoding( Encoding enc ) {
         short ptr=enc.reg(ptr()), idx=enc.reg(idx()), src=enc.reg(val());
         if( src==-1 ) X86.storeImm(enc,Integer.numberOfTrailingZeros(_sz-'0'),_imm,ptr,idx,_off,_scale);
diff --git a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
index 3d71b4ea..dc15b185 100644
--- a/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
+++ b/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/x86_64_v2.java
@@ -87,6 +87,18 @@ public class x86_64_v2 extends Machine {
         default -> throw new IllegalArgumentException("Too many arguments");
         };
     }
+    static int jumpop(String op, boolean unsigned) {
+        if( !unsigned ) return jumpop(op);
+        return switch( op ) {
+            case "==" -> 0x84;
+            case "!=" -> 0x85;
+            case "<"  -> 0x82;
+            case "<=" -> 0x86;
+            case ">"  -> 0x87;
+            case ">=" -> 0x83;
+            default -> throw new IllegalArgumentException(op);
+        };
+    }
 
     // Limit of float args passed in registers
     static RegMask[] XMMS8 = new RegMask[]{
@@ -282,6 +294,7 @@ public class x86_64_v2 extends Machine {
     public Node instSelect(Node n) {
         return switch (n) {
         case AddNode      add -> add(add);
+        case Intrinsic.BitCastNode cast -> new BitCastX86(cast);
         case AndNode      and -> and(and);
         case BoolNode    bool -> cmp(bool);
         case CLInitNode  init -> new CLInitNode(init);
@@ -298,10 +311,7 @@ public class x86_64_v2 extends Machine {
         case IfNode       iff -> jmp(iff);
         case LoadNode      ld -> ld(ld);
         case MemMergeNode mem -> new MemMergeNode(mem);
-        case MinusNode    neg -> {
-            if( neg.mode()==2 ) throw Utils.TODO();
-            yield new NegX86(neg);
-        }
+        case MinusNode    neg -> neg.mode()==2 ? new NegFX86(neg) : new NegX86(neg);
         case MulNode      mul -> mul.mode()==2 ? new MulFX86(mul) : mul(mul);
         case NewNode      nnn -> new NewX86(nnn);
         case NotNode      not -> new NotX86(not);
@@ -370,8 +380,9 @@ public class x86_64_v2 extends Machine {
 
     private Node _lea(Node add, Node base, Node idx, int off) {
         int scale = 0;
-        if( base instanceof ShlNode && !(idx instanceof ShlNode) )
-            throw Utils.TODO(); // Bug in canonicalization, should on RHS
+        if( base instanceof ShlNode && !(idx instanceof ShlNode) ) {
+            Node tmp = base; base = idx; idx = tmp;
+        }
         if( idx instanceof ShlNode shift && shift.in(2) instanceof ConstantNode shfcon &&
             shfcon._con instanceof TypeInteger tscale && 0 <= tscale.value() && tscale.value() <= 3 ) {
             idx = shift.in(1);
diff --git a/src/main/java/com/seaofnodes/simple/parser/Allocations.java b/src/main/java/com/seaofnodes/simple/parser/Allocations.java
index 861f95b6..64234045 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Allocations.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Allocations.java
@@ -25,11 +25,20 @@ final class Allocations {
         }
         // Parse ary[ length_expr ]
         if( P.match("[") ) {
-            if( !t.makeZero().isa(t) )
-                throw Parser.error("Cannot allocate a non-nullable, since arrays are always zero/null filled",site);
+            boolean readonly = P.match("~");
+            if( P.match("]") ) {
+                P.require("{");
+                return P.arrays.parse(t,readonly,null,site);
+            }
             Node len = P.expressions.parseAssignment().keep();
             P.require("]");
+            if( P.match("{") ) return P.arrays.parse(t,readonly,len,site);
+            if( !t.makeZero().isa(t) )
+                throw Parser.error("Cannot allocate a non-nullable, since arrays are always zero/null filled",site);
+            if( readonly ) return new ReadOnlyNode(allocArray(P.types.typeAry(t,true),len)).peephole();
             return allocArray(P.types.typeAry(t,false),len);
+        } else if( t instanceof TypeMemPtr ary && ary._obj.isAry() && P.match("{") ) {
+            return P.arrays.parse(ary._obj.field("[]")._t,ary._ro,null,site);
         } else {
             if( !(t instanceof TypeMemPtr tmp) )
                 throw Parser.error("Cannot allocate a "+t.str(),site);
@@ -101,8 +110,6 @@ final class Allocations {
         // TODO: Needs runtime check.
         Node st = P.peep(new StoreNode(null, "#", 1, TypeInteger.U32, null, smem, self, ConFldOffNode.make(ts,"#"), len.unkeep(), true));
 
-        // TODO: Allow add-on "constructor" to init the array elements
-
         Node prior = P.mem();
         Node esc = P.peep(new EscapeNode(lenFld,self,st,prior));
         P.mem(P.mergeAlias(prior,lenFld._alias,esc));
@@ -117,7 +124,7 @@ final class Allocations {
         TypeStruct ts = P.types.typeAry(TypeInteger.U8,true);
         int  lenAlias = ts.field("#" )._alias;
         int elemAlias = ts.field("[]")._alias;
-        TypeConAryB body = TypeConAryB.make(s);
+        TypeConAry body = TypeConAry.make(s);
         TypeInteger slen = TypeInteger.constant(s.length);
         // Make a TMP, not-null (byte)2, singleton (true) (requires text
         // strings are hash-interned), with a TypeStruct having a constant
diff --git a/src/main/java/com/seaofnodes/simple/parser/ArrayInitializers.java b/src/main/java/com/seaofnodes/simple/parser/ArrayInitializers.java
new file mode 100644
index 00000000..079853cd
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/parser/ArrayInitializers.java
@@ -0,0 +1,187 @@
+package com.seaofnodes.simple.parser;
+
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.node.ScopeNode.Kind;
+import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.Ary;
+
+/** Array construction keeps the destination private until all elements exist.
+ * A generator is a scoped, immediately executed loop body, not an escaping closure. */
+final class ArrayInitializers {
+    private final Parser P;
+    Frame _frame;
+
+    static final class Frame {
+        final Kind.Block _kind;
+        final int _depth;
+        final Var _value;
+        ScopeNode _returns;
+        Frame(Kind.Block kind, int depth, Var value) {
+            _kind=kind; _depth=depth; _value=value;
+        }
+    }
+
+    ArrayInitializers(Parser P) { this.P=P; }
+
+    // Opening brace consumed; an absent length means a list with inferred size.
+    Node parse(Type elem, boolean readonly, Node len, Lexer site) {
+        int pos=P.pos();
+        Type indexType=P.types.parseType();
+        String index=indexType==null ? null : P._lexer.matchId();
+        boolean generator=index!=null && P.match("->");
+        if( !generator ) P.pos(pos);
+        if( generator && Parser.KEYWORDS.contains(index) )
+            throw Parser.error("Expected an array index name",site);
+        if( generator && (indexType!=TypeInteger.BOT && indexType!=TypeInteger.I32 && indexType!=TypeInteger.U32) )
+            throw Parser.error("Array generator index must be int, i64, or u32",site);
+        if( generator && len==null )
+            throw Parser.error("Array generator requires a length",site);
+
+        Ary<Node> values=new Ary<>(Node.class);
+        if( !generator ) {
+            if( !P.peek('}') ) do {
+                values.add(P.conversions.convertExpr(P.expressions.parseAssignment(),elem).keep());
+            } while( P.match(",") && !P.peek('}') );
+            P.require("}");
+            if( len==null ) len=P.con(values.size()).keep();
+        }
+
+        TypeStruct ts=P.types.typeAry(elem,readonly);
+        Field body=ts.field("[]"), length=ts.field("#");
+        Node size=new AddNode(ConFldOffNode.make(ts,"[]"),
+                             new ShlNode(null,len,P.con(ts.aryScale())).peephole()).peephole();
+        NewNode alloc=new NewNode(ts,P.ctrl(),size).init();
+        Node self=new ProjNode(alloc,0,ts.str()).init().keep();
+        Node mem=new ProjNode(alloc,1,"#arrayMem").init().keep();
+        Node slen=new StoreNode(site,"#",length._alias,TypeInteger.U32,null,mem,self,
+                               ConFldOffNode.make(ts,"#"),len,true).peephole().keep();
+
+        if( generator ) {
+            mem=generator(ts,self,mem,len,index,indexType,site);
+        } else {
+            for( int i=0; i<values.size(); i++ ) {
+                Node st=store(ts,self,mem,P.con(i),values.at(i),site).keep();
+                mem.unkeep();
+                mem=st;
+            }
+        }
+
+        Node result=new ArrayInitNode(P.ctrl(),mem,self,len,
+                                      generator ? -1 : values.size(),site,values).peephole().keep();
+        Node prior=P.mem();
+        P.mem(P.mergeAlias(prior,length._alias,new EscapeNode(length,result,slen.unkeep(),prior).peephole()));
+        prior=P.mem();
+        P.mem(P.mergeAlias(prior,body._alias,new EscapeNode(body,result,mem,prior).peephole()));
+        mem.unkeep(); self.unkeep(); len.unkeep();
+        for( Node value : values ) value.unkeep();
+        result.unkeep();
+        return readonly ? new ReadOnlyNode(result).peephole() : result;
+    }
+
+    private Node store(TypeStruct ts, Node self, Node mem, Node idx, Node value, Lexer site) {
+        Field fld=ts.field("[]");
+        Node off=new AddNode(ConFldOffNode.make(ts,"[]"),
+                             new ShlNode(null,idx,P.con(ts.aryScale())).peephole()).peephole();
+        return new StoreNode(site,"[]",fld._alias,fld._t,P.ctrl(),mem,self,off,value,true).peephole();
+    }
+
+    private Var define(String name, Type type, boolean fin, Node value, Lexer site) {
+        if( !P._scope.define(name,type,fin,value,site) ) throw Parser.error("Duplicate name '"+name+"'",site);
+        return P._scope.lookup(name);
+    }
+
+    private Node read(Var var) { return P._scope.in(P._scope.update(var,null)); }
+
+    private Node generator(TypeStruct ts, Node self, Node mem, Node len, String name,
+                           Type indexType, Lexer site) {
+        Frame outer=_frame;
+        ScopeNode oldBreak=P.statements._breakScope, oldContinue=P.statements._continueScope;
+        P.statements._breakScope=P.statements._continueScope=null;
+        Kind.Block kind=new Kind.Block();
+        P._scope.push(kind);
+        // The counter stays wide even when the source index is a narrow int.
+        // The private memory and result slots cannot be named in source.
+        Var counter=define("$arrayIndex",TypeInteger.BOT,false,P.con(0),site);
+        Var memory=define("$arrayMem",TypeMem.makePrivate(Type.BOTTOM),false,mem.unkeep(),site);
+        Var result=define("$arrayValue",ts.field("[]")._t,false,P.con(Type.TOP),site);
+        _frame=new Frame(kind,P._scope.depth(),result);
+
+        P.ctrl(new LoopNode(site,null,P.ctrl()).peephole());
+        ScopeNode head=P._scope.keep();
+        P._xScopes.push(P._scope=P._scope.dup(true));
+        Node idx=read(counter).keep();
+        Node pred=new BoolNode.LT(idx,len).peephole().keep();
+        Node iff=new IfNode(P.ctrl(),pred).peephole().keep();
+        CFGNode yes=new CProjNode(iff,0,"True").peephole().keep();
+        CFGNode no=(CFGNode)new CProjNode(iff.unkeep(),1,"False").peephole();
+        P.ctrl(no);
+        ScopeNode exit=P._scope.dup();
+        P._xScopes.push(exit);
+        exit.addGuards(no,pred,true);
+        P.ctrl(yes.unkeep());
+        P._scope.addGuards(yes,pred.unkeep(),false);
+
+        P._scope.push(new Kind.Block());
+        define(name,indexType,true,new ConvertNode(indexType,idx).peephole(),site);
+        Node last=P._code.ZERO;
+        while( !P.peek('}') && !P._lexer.isEOF() ) {
+            P._code.add(last);
+            last=P.statements.parseStatement();
+        }
+        P.require("}");
+        if( P.ctrl()._type!=Type.XCONTROL ) addReturn(last);
+        P._scope.pop();
+        if( _frame._returns!=null ) {
+            P._scope.kill();
+            P._scope=_frame._returns;
+        }
+        Node value=read(result);
+        // The loop starts with the whole private array memory. Keep that shape
+        // on the backedge too: mixing it with an element slice yields BOTTOM,
+        // which would falsely publish every function when the array escapes.
+        Node prior=read(memory).keep();
+        Node st=store(ts,self,prior,idx,value,site);
+        P._scope.update(memory,P.mergeAlias(prior.unkeep(),ts.field("[]")._alias,st));
+        P._scope.update(counter,new AddNode(idx.unkeep(),P.con(1)).peephole());
+        P._scope.removeGuards(yes);
+        head.balanceLoopFRefs(P._scope);
+        exit.balanceLoopFRefs(P._scope);
+        head.endLoop(P._scope,exit);
+        head.unkeep().kill();
+        P._xScopes.pop();
+        P._xScopes.pop();
+        if( !P._xScopes.isEmpty() ) { P._xScopes.pop(); P._xScopes.push(exit); }
+        P._scope=exit;
+        Node done=read(memory).keep();
+        P._scope.pop();
+        _frame=outer;
+        P.statements._breakScope=oldBreak;
+        P.statements._continueScope=oldContinue;
+        return done;
+    }
+
+    Node addReturn(Node expr) {
+        Node value=P.conversions.convertExpr(expr,_frame._value.type());
+        value=new ArrayInitNode(P.ctrl(),value,P.loc()).peephole().keep();
+        P.mem(); // Materialize lazy memory before cloning a return path.
+        ScopeNode cur=P._scope.dup();
+        // Saved paths share Var records with the active scope. Drop locals
+        // without promoting them, then copy forward references explicitly.
+        while( cur.depth()>_frame._depth ) cur._pop();
+        cur.balanceLoopFRefs(P._scope);
+        cur.update(_frame._value,value.unkeep());
+        if( _frame._returns==null ) _frame._returns=cur;
+        else {
+            _frame._returns.balanceLoopFRefs(cur);
+            cur.balanceLoopFRefs(_frame._returns);
+            _frame._returns.ctrl(_frame._returns.mergeScopes(cur,P.loc()).peephole());
+        }
+        P.ctrl(P._code.XCTRL);
+        return P._code.ZERO;
+    }
+
+    void checkAssignment(Var var, Lexer site) {
+        if( _frame!=null && var._idx<_frame._kind._lexSize )
+            throw Parser.error("Cannot assign captured local '"+var._name+"' in an array generator",site);
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/parser/Conversions.java b/src/main/java/com/seaofnodes/simple/parser/Conversions.java
index fa11311d..72247ca6 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Conversions.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Conversions.java
@@ -37,7 +37,7 @@ final class Conversions {
         case TypeFloat   tf -> TypeFloat.F64;
         case TypeMemPtr tmp -> tmp.makeVar();
         case TypeFunPtr tfp -> tfp;
-        case TypeConAry<?> a -> a;
+        case TypeConAry a -> a;
         case TypePtr     ptr -> TypePtr.PTR;
         case TypeScalar  ts -> TypeScalar.BOT;
         default             -> t;
diff --git a/src/main/java/com/seaofnodes/simple/parser/Declarations.java b/src/main/java/com/seaofnodes/simple/parser/Declarations.java
index 13fa59b8..473a7c24 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Declarations.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Declarations.java
@@ -91,6 +91,10 @@ final class Declarations {
             // expr is a constant function
             if( t instanceof TypeFunPtr decl && expr._type instanceof TypeFunPtr tfp && tfp.isConstant() ) {
                 t = decl.makeFrom(tfp.fidx());
+                // The explicit signature specifies source parameters/return;
+                // the receiver of a method body is still inferred.
+                if( expr instanceof FunPtrNode && P.structs.inStructDeclaration() )
+                    t = ((TypeFunPtr)t).makeFrom(tfp.arg(0),0);
                 FunNode fun = P._code.link(tfp);
                 if( fun != null )
                     fun.setName(name); // Assign debug name to Simple function
diff --git a/src/main/java/com/seaofnodes/simple/parser/Expressions.java b/src/main/java/com/seaofnodes/simple/parser/Expressions.java
index 247d974e..6486aba8 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Expressions.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Expressions.java
@@ -400,7 +400,7 @@ final class Expressions {
      * Parse integer literal
      *
      * <pre>
-     *     integerLiteral: [1-9][0-9]* | [0]
+     *     integerLiteral: [1-9][0-9]* | 0[0-7]* | 0[xX][0-9a-fA-F]+
      *     floatLiteral: [digits].[digits]?[e [digits]]?[f]?
      * </pre>
      */
diff --git a/src/main/java/com/seaofnodes/simple/parser/Functions.java b/src/main/java/com/seaofnodes/simple/parser/Functions.java
index 5175acc6..84bd509e 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Functions.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Functions.java
@@ -14,6 +14,11 @@ final class Functions {
     // Merge all function exits here.
     ScopeNode _returnScope;
 
+    // Instance method headers are available immediately; their bodies need
+    // the complete field scope, just like explicitly declared constructors.
+    private record Method(FunPtrNode ptr, Lexer body, Lexer loc, BitSet finals, String[] ids) {}
+    private Ary<Method> _methods;
+
     Functions(Parser P) { this.P = P; }
 
     /**
@@ -29,6 +34,7 @@ final class Functions {
         Ary<String> ids = new Ary<>(String.class);
         BitSet finals = new BitSet();
         Type self = P.types.implicitSelfType();
+        if( P.structs.inStructDeclaration() ) self = self.makeRO();
         ts.push(self);
         ids.push(self == TypePtr.PTR ? "#self" : "self");
 
@@ -38,10 +44,49 @@ final class Functions {
         parameters(ts,ids,finals,false);
         // Make a concrete function type, with a fidx
         TypeFunPtr tfp = TypeFunPtr.make1((byte)2,true,ts.asAry(),Type.BOTTOM,P._code.fidx(P._ref._cname));
+        if( P.structs.inStructDeclaration() ) {
+            FunPtrNode ptr = (FunPtrNode)new FunPtrNode(tfp,P._code._start,null).peephole().keep();
+            _methods.push(new Method(ptr,P.loc(),loc,finals,ids.asAry()));
+            P._lexer.skipTo('{','}',"method body");
+            return ptr;
+        }
         ReturnNode ret = parseFunctionBody(tfp,loc,finals,ids.asAry());
         return new FunPtrNode(tfp,P._code._start,ret).peephole();
     }
 
+    private void finishMethods() {
+        if( _methods == null ) return;
+        Ary<Method> methods = _methods;
+        Lexer after = P._lexer;
+        for( Method method : methods ) {
+            P._lexer = new Lexer(method.body());
+            TypeFunPtr sig = (TypeFunPtr)method.ptr()._con;
+            ReturnNode ret = parseFunctionBody(sig,method.loc(),method.finals(),method.ids());
+            method.ptr().setDef(1,ret);
+            P.require("}");
+        }
+        Ary<FunNode> functions = new Ary<>(FunNode.class);
+        for( Method method : methods ) functions.add(method.ptr().fun());
+        MethodAccess.infer(functions);
+        for( Method method : methods ) {
+            ReturnNode ret = method.ptr().ret();
+            TypeFunPtr sig = ret.fun().sig();
+            method.ptr().peephole();
+            // Declarations saw the header before its FunNode existed.
+            for( Var var : P._scope._vars )
+                if( var.type() instanceof TypeFunPtr tfp && tfp.isConstant() && tfp.fidx() == sig.fidx() ) {
+                    ret.fun().setName(var._name);
+                    var.refineType(var.type().join(method.ptr()._type));
+                    TypeStruct self = P._scope.constructorSelf();
+                    TypeStruct shape = (TypeStruct)Parser.TYPES.get(self._name);
+                    Parser.TYPES.put(shape._name,shape.replace(shape.field(var._name).makeFrom(var.type())));
+                    break;
+                }
+            method.ptr().unkeep();
+        }
+        P._lexer = after;
+    }
+
     Node parseConstructor(String name, boolean explicit) {
         P.require("{");
         Ary<Type> ts = new Ary<>(Type.class);
@@ -198,9 +243,13 @@ final class Functions {
     }
 
     ReturnNode parseBody( String funName, TypeFunPtr sig, Lexer loc, BitSet finals, String[] ids) {
+        ArrayInitializers.Frame outerArray = P.arrays._frame;
+        P.arrays._frame = null;
         Structs.Constructor outerCtor = P.structs._pendingCtor;
         P.structs._pendingCtor = null;
         boolean isInit = FunNode.isInit(funName);
+        Ary<Method> outerMethods = _methods;
+        _methods = FunNode.isInstance(funName) ? new Ary<>(Method.class) : null;
         boolean isCtor = isInit || P.structs.isExplicitConstructorName(funName);
         String typeName = isCtor ? ((TypeMemPtr)sig._sig[0])._obj._name : null;
 
@@ -233,7 +282,11 @@ final class Functions {
                 nvar = P.structs.updateSelfAsFieldsDiscovered( typeName, nvar );
         }
 
-        if( isInit ) P.structs.finishConstructor();
+        if( isInit ) {
+            finishMethods();
+            P.structs.finishConstructor();
+        }
+        _methods = outerMethods;
         P.structs._pendingCtor = outerCtor;
 
         ParmNode self = fun.parm(2);
@@ -275,6 +328,7 @@ final class Functions {
         P.statements._breakScope    =    breakScope;
         P._scope.pop();
         P.construction._frame = outerConstruction;
+        P.arrays._frame = outerArray;
 
         return ret;
     }
@@ -300,8 +354,14 @@ final class Functions {
         // All args, "as-if" called externally
         for( int i = 0; i<ids.length; i++ ) {
             Type t = sig.arg(i);
+            // Parse an implicit receiver with write access, then infer the
+            // public requirement from its uses once every method is present.
+            if( i == 0 && ids[0].equals("self") && !FunNode.isInit(funName) &&
+                !(sig.ret() instanceof TypeMem) && t instanceof TypeMemPtr ptr )
+                t = ptr.withAccess(false);
             // Args take a default input if called from Start/external-world
-            Node parm = new ParmNode(ids[i],i+2,t,fun,ConstantNode.seed(fun.defaultArg(i)).peephole()).peephole();
+            Type seed = i == 0 && t instanceof TypeMemPtr ? t : fun.defaultArg(i);
+            Node parm = new ParmNode(ids[i],i+2,t,fun,ConstantNode.seed(seed).peephole()).peephole();
             if( t instanceof TypeMemPtr ptr && ptr._partial ) parm = new ConstructNode(parm).peephole();
             P._scope.define(ids[i], t, (i==0 && ids[0]=="self") || (finals!=null && finals.get(i)), parm, loc);
         }
diff --git a/src/main/java/com/seaofnodes/simple/parser/Lexer.java b/src/main/java/com/seaofnodes/simple/parser/Lexer.java
index 5e4b7311..62dd054e 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Lexer.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Lexer.java
@@ -239,6 +239,7 @@ public class Lexer {
     // Return a constant Type, either TypeInteger or TypeFloat
     Type parseNumber() {
         Lexer start=new Lexer(this);
+        if( isHex() ) return parseInteger(parseNumberString(),16,2,start);
         int old = _position;
         int len = isLongOrDouble();
         boolean f32 = peek()=='f';
@@ -250,7 +251,7 @@ public class Lexer {
                 return TypeFloat.constant(Float.parseFloat(literal));
             if( len > 0 ) {
                 if( len > 1 && _input[old]=='0' )
-                    throw Parser.error("Syntax error: integer values cannot start with '0'",start);
+                    return parseInteger(literal,8,0,start);
                 long i = Long.parseLong(literal);
                 return TypeInteger.constant(i);
             }
@@ -262,6 +263,11 @@ public class Lexer {
     }
     private String parseNumberString() {
         int old = _position;
+        if( isHex() ) {
+            _position += 2;
+            while( isIdLetter(peek()) ) inc();
+            return new String(_input,old,_position-old);
+        }
         int len = Math.abs(isLongOrDouble());
         if( peek()=='f' ) {
             nextChar();
@@ -270,6 +276,24 @@ public class Lexer {
         return new String(_input,old,len);
     }
 
+    private boolean isHex() {
+        return peek()=='0' && _position+1<_input.length && (peek(1)=='x' || peek(1)=='X');
+    }
+
+    private TypeInteger parseInteger(String literal, int radix, int prefix, Lexer start) {
+        String kind = radix==16 ? "Hexadecimal" : "Octal";
+        if( literal.length()==prefix )
+            throw Parser.error(kind+" integer literal requires at least one digit",start);
+        for( int i=prefix; i<literal.length(); i++ )
+            if( Character.digit(literal.charAt(i),radix)<0 )
+                throw Parser.error("Invalid "+kind.toLowerCase()+" integer literal '"+literal+"'",start);
+        try {
+            return TypeInteger.constant(Long.parseUnsignedLong(literal.substring(prefix),radix));
+        } catch( NumberFormatException ex ) {
+            throw Parser.error(kind+" integer literal exceeds 64 bits",start);
+        }
+    }
+
     // Return +len that ends a long
     // Return -len that ends a double
     private int isLongOrDouble() {
@@ -381,14 +405,19 @@ public class Lexer {
             precision = formatNumber(site);
         }
         char kind=nextChar();
-        if( "diuoxXfFeEgGaAcsb".indexOf(kind)<0 )
+        if( "diuoxXfFeEgGaAcsbt".indexOf(kind)<0 )
             throw Parser.error("Expected a string format: %(expression), %d(expression), or %%",site);
         boolean number="diuoxXfFeEgGaA".indexOf(kind)>=0;
         if( !number && (flags&~1)!=0 || "uoxX".indexOf(kind)>=0 && (flags&6)!=0 ||
             "diu".indexOf(kind)>=0 && (flags&8)!=0 )
             throw Parser.error("Invalid flags for %"+kind,site);
-        if( precision>=0 && (kind=='c' || kind=='b') )
+        if( precision>=0 && (kind=='c' || kind=='b' || kind=='t') )
             throw Parser.error("Precision is not supported for %"+kind,site);
+        if( kind=='t' && peek()!='(' ) {
+            int style="FrRMDT".indexOf(nextChar());
+            if( style<0 ) throw Parser.error("Expected a time format: %t, %tF, %tr, %tR, %tM, %tD, or %tT",site);
+            flags |= style<<8;
+        }
         if( peek()!='(' ) throw Parser.error("Expected '(' after string format %"+kind,site);
         inc();
         return new Format(kind,flags,width,precision,site);
diff --git a/src/main/java/com/seaofnodes/simple/parser/MethodAccess.java b/src/main/java/com/seaofnodes/simple/parser/MethodAccess.java
new file mode 100644
index 00000000..099ba036
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/parser/MethodAccess.java
@@ -0,0 +1,130 @@
+package com.seaofnodes.simple.parser;
+
+import com.seaofnodes.simple.node.*;
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.type.*;
+import com.seaofnodes.simple.util.Ary;
+import java.util.ArrayDeque;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Collections;
+import java.util.IdentityHashMap;
+import java.util.Set;
+
+/** Infer the access required through an instance method's receiver. */
+final class MethodAccess {
+    private final FunNode _fun;
+    private final Set<Node> _aliases = Collections.newSetFromMap(new IdentityHashMap<>());
+    private final Set<MethodAccess> _calls = new HashSet<>();
+    private boolean _writes;
+
+    private MethodAccess(FunNode fun) { _fun = fun; }
+
+    static void infer(Ary<FunNode> functions) {
+        HashMap<Integer,MethodAccess> methods = new HashMap<>();
+        for( FunNode fun : functions ) methods.put(fun.sig().fidx(),new MethodAccess(fun));
+        for( MethodAccess method : methods.values() ) method.scan(methods);
+        boolean changed;
+        do {
+            changed = false;
+            for( MethodAccess method : methods.values() )
+                if( !method._writes )
+                    for( MethodAccess callee : method._calls )
+                        if( callee._writes ) { method._writes = true; changed = true; break; }
+        } while( changed );
+        for( MethodAccess method : methods.values() ) method.finish();
+    }
+
+    private void scan(HashMap<Integer,MethodAccess> methods) {
+        if( _fun.parm(2) == null ) return; // Unused receiver.
+        ArrayDeque<Node> work = new ArrayDeque<>();
+        work.add(_fun.parm(2));
+        while( !work.isEmpty() ) {
+            Node value = work.remove();
+            if( !_aliases.add(value) ) continue;
+            for( Node use : value._outputs ) {
+                if( use == null || use instanceof ReadOnlyNode ) continue;
+                if( use instanceof StoreNode store ) {
+                    if( store.ptr() == value || store.val() == value ) _writes = true;
+                } else if( use instanceof CallNode call ) {
+                    for( int i = 2; i < call.nIns()-1; i++ )
+                        if( call.in(i) == value ) call(call,i-2,methods);
+                } else if( use instanceof ReturnNode ret ) {
+                    // Returning a writable alias must not grant write access
+                    // to an object reached through a read-only receiver.
+                    if( ret.expr() == value ) _writes = true;
+                } else if( use instanceof LoadNode load && load.ptr() == value ) {
+                    Type type = type(load);
+                    if( type instanceof TypeMemPtr ptr ) {
+                        if( !ptr._ro ) work.add(load);
+                    } else if( type == Type.BOTTOM || type == TypeScalar.BOT ) _writes = true;
+                } else if( use instanceof PhiNode || use instanceof GuardNode ) {
+                    work.add(use);
+                } else if( use instanceof ConvertNode convert ) {
+                    if( !(convert.dst() instanceof TypeMemPtr ptr && ptr._ro) ) _writes = true;
+                } else if( use instanceof BoolNode || use instanceof NotNode ||
+                           use instanceof FldOffNode || use instanceof ScopeNode || use instanceof CLInitNode ) {
+                    // Comparisons and field offsets do not expose write access.
+                } else {
+                    // Includes raw-address casts and unrecognized escapes.
+                    _writes = true;
+                }
+            }
+        }
+    }
+
+    private void call(CallNode call, int arg, HashMap<Integer,MethodAccess> methods) {
+        // Every member of this struct is now declared. An unresolved bare
+        // function name belongs to an outer scope, whose hidden slot is not self.
+        if( arg == 0 && call.fptr() instanceof FRefNode ) return;
+        Type type = type(call.fptr());
+        if( !(type instanceof TypeFunPtr sig) || arg >= sig.nargs() ) { _writes = true; return; }
+        if( arg == 0 && sig.arg(0) == TypePtr.PTR ) return;
+        if( arg == 0 ) {
+            if( XInt.isHigh(sig.fidxs()) ) { _writes = true; return; }
+            for( int fidx = XInt.next(sig.fidxs(),-1); fidx >= 0; fidx = XInt.next(sig.fidxs(),fidx) ) {
+                MethodAccess local = methods.get(fidx);
+                if( local != null ) _calls.add(local);
+                else {
+                    FunNode target = CodeGen.CODE.link(fidx);
+                    Type receiver = target == null ? sig.arg(0) : target.sig().arg(0);
+                    if( !(receiver instanceof TypeMemPtr ptr && ptr._ro) ) _writes = true;
+                }
+            }
+            return;
+        }
+        if( !(sig.arg(arg) instanceof TypeMemPtr ptr && ptr._ro) ) _writes = true;
+    }
+
+    private static Type type(Node value) {
+        // Flow types can still be BOTTOM while the parser discovers fields.
+        if( value instanceof LoadNode load ) {
+            TypeStruct obj = load.off() instanceof ConFldOffNode off ? off._ts :
+                type(load.ptr()) instanceof TypeMemPtr ptr ? ptr._obj : null;
+            if( obj != null ) {
+                if( !obj.isAry() && Parser.TYPES.get(obj._name) instanceof TypeStruct latest ) obj = latest;
+                Field field = obj.field(load._name);
+                if( field != null ) return field._t;
+            }
+        }
+        return value._type;
+    }
+
+    private void finish() {
+        ParmNode self = _fun.parm(2);
+        if( self == null ) return;
+        TypeMemPtr receiver = ((TypeMemPtr)self._declaredType).withAccess(!_writes);
+        _fun.setSig(_fun.sig().makeFrom(receiver,0));
+        if( _writes ) return;
+        self._declaredType = receiver;
+        self.setDef(1,ConstantNode.seed(receiver).peephole());
+        // These parser-time assumptions are settled before Iter/SCCP. No
+        // writable alias escapes a method classified as read-only.
+        for( Node alias : _aliases )
+            if( alias._type instanceof TypeMemPtr ptr ) {
+                alias._type = ptr.makeRO();
+                CodeGen.CODE.add(alias);
+                CodeGen.CODE.addAll(alias._outputs);
+            }
+    }
+}
diff --git a/src/main/java/com/seaofnodes/simple/parser/Parser.java b/src/main/java/com/seaofnodes/simple/parser/Parser.java
index 0cf3c0e7..9c18385d 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Parser.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Parser.java
@@ -7,7 +7,7 @@ import com.seaofnodes.simple.type.*;
 import com.seaofnodes.simple.util.Ary;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.LinkedHashSet;
+import java.util.LinkedHashMap;
 import java.util.Stack;
 
 /** Source-unit entry point and shared cursor, scope, and IR utilities.
@@ -21,6 +21,7 @@ public class Parser {
     final Functions functions = new Functions(this);
     final Structs structs = new Structs(this);
     final Allocations allocations = new Allocations(this);
+    final ArrayInitializers arrays = new ArrayInitializers(this);
     final References references = new References(this);
     final Conversions conversions = new Conversions(this);
     final Construction construction = new Construction(this);
@@ -91,7 +92,7 @@ public class Parser {
     public final Stack<ScopeNode> _xScopes = new Stack<>();
     // Layouts needed by field accesses in this source file.  Resolve after
     // parsing, since a later local struct declaration can satisfy the use.
-    public final LinkedHashSet<String> _requiredTypes = new LinkedHashSet<>();
+    public final LinkedHashMap<String,Lexer> _requiredTypes = new LinkedHashMap<>();
 
     // Mapping from a type name to a Type.  The string name matches
     // `type.str()` call.
@@ -120,6 +121,11 @@ public class Parser {
         public final Lexer _loc;
         ParseException( String msg, Lexer loc ) { super(msg); _loc = loc==null ? null : new Lexer(loc); }
         public String diagnostic() { return _loc==null ? getMessage() : _loc.diagnostic(getMessage()); }
+        // JUnit and uncaught-exception reporters use these entry points rather
+        // than the CLI's diagnostic(). Source errors should retain their source
+        // excerpt and caret there too. getMessage() stays stable for callers.
+        @Override public void printStackTrace(java.io.PrintStream out) { out.println(diagnostic()); }
+        @Override public void printStackTrace(java.io.PrintWriter out) { out.println(diagnostic()); }
     }
 
     public Parser(CodeGen code ) {
@@ -265,7 +271,7 @@ public class Parser {
     // Field offset for an unknown type
     public Node fldoff( Node n, String name ) {
         if( n._type instanceof TypeMemPtr ptr && ptr._obj._fref )
-            _requiredTypes.add(ptr._obj._name);
+            _requiredTypes.putIfAbsent(ptr._obj._name,loc());
         return new FldOffNode(n,name,loc()).peephole();
     }
     public Node peep( Node n ) {
diff --git a/src/main/java/com/seaofnodes/simple/parser/README.md b/src/main/java/com/seaofnodes/simple/parser/README.md
index cee1d64a..48cf13c8 100644
--- a/src/main/java/com/seaofnodes/simple/parser/README.md
+++ b/src/main/java/com/seaofnodes/simple/parser/README.md
@@ -2,7 +2,7 @@
 
 The parser builds Sea-of-Nodes IR directly. Each component shares the cursor,
 active scope, and compilation state through its `Parser P` reference; there is no intermediate
-AST. The [grammar map](../../../../../../../docs/chapter30/30-grammar.md) connects language
+AST. The [grammar map](../../../../../../../docs/chapter31/31-grammar.md) connects language
 productions to their entry points.
 
 | File | Responsibility |
@@ -14,6 +14,7 @@ productions to their entry points.
 | `Declarations.java` | Bindings, initializers, mutability modifiers, and native declarations. |
 | `Types.java` | Type syntax, qualified-name lookup, arrays, function types, and forward types. |
 | `Functions.java` | Function expressions, parameters, arguments, calls, and function entry/return graphs. |
+| `MethodAccess.java` | Infers whether an instance method needs writable access through its receiver. |
 | `Structs.java` | Struct and constructor declarations, field discovery, and initialization Stores. |
 | `Construction.java` | Selects private self memory during parsing; its comment explains BOT fields, the TypeMemPtr qualifier, and checks deferred to TypeCheck. |
 | `References.java` | Bare-name and field resolution, implicit receivers, assignments, and forward references. |
@@ -23,8 +24,16 @@ productions to their entry points.
 | `Var.java` | Lexical binding metadata: name, type, scope slot, and mutability. |
 
 Start with `Statements.parseStatement` or `Expressions.parseAssignment` to follow
-the grammar. Loop updates are parsed after their bodies, and declared constructor
-bodies after field discovery; `Lexer.skipTo` scans these deferred fragments.
+the grammar. Loop updates are parsed after their bodies. Instance method headers
+are parsed immediately, but their bodies and declared constructor bodies wait
+until all fields are known. Methods can therefore use fields declared later in
+the struct. `Lexer.skipTo` scans these deferred fragments.
+
+Method receivers accept read-only access unless the body needs writable access.
+The check follows aliases, child references, array elements, and calls between
+methods. Writing an independent argument does not require a writable receiver.
+Returning or storing a writable receiver alias also requires writable access;
+an explicit read-only view can be exposed without that requirement.
 
 `Parser` keeps the short cursor, scope/memory, IR-building, and diagnostic helpers
 used by these components. Independent helpers live with their data: class-object
diff --git a/src/main/java/com/seaofnodes/simple/parser/References.java b/src/main/java/com/seaofnodes/simple/parser/References.java
index 6335bad2..7724103e 100644
--- a/src/main/java/com/seaofnodes/simple/parser/References.java
+++ b/src/main/java/com/seaofnodes/simple/parser/References.java
@@ -120,6 +120,7 @@ final class References {
             return P.expressions.parsePostfixMethod(P.construction.view(rvalue),P._scope.in(P._scope.update(P._scope.var(selfx),null)));
         }
         // Assign-update direct into Scope
+        P.arrays.checkAssignment(var,site);
         if( var._final && !P._scope.canInit(var) )
             throw Parser.error("Cannot reassign final '"+var._name+"'",site);
         checkSharedFunction(var);
@@ -130,6 +131,7 @@ final class References {
     }
 
     void checkAssignment(Var def, Lexer site) {
+        if( fieldSelf(def)==null ) P.arrays.checkAssignment(def,site);
         String name = def._name;
         // A final field may receive its first value in its constructor.
         if( P._scope.in(def._idx)._type!=Type.TOP && def._final &&
@@ -278,7 +280,7 @@ final class References {
         // Check for assign-update, "ptr.fld += expr" or "ary[idx]++"
         char ch = pre==0 ? P._lexer.matchOperAssign() : (char)pre;
         if( ch!=0 ) {
-            if( fld!=null && decl==Type.BOTTOM )
+            if( fld!=null && decl==Type.BOTTOM && !ts._fref )
                 throw Parser.error( "'" + ts._name + "' is not fully initialized, field '" + fld._fname + "' needs to be set in a constructor",site );
             Node op = P.expressions.opAssign(ch,load, decl ).keep();
             mem.keep();
@@ -306,10 +308,15 @@ final class References {
     // Fields are lvalues in memory, including inside their initializer and
     // explicit constructor. Scope slots retain declaration metadata only.
     private Node fieldSelf(Var var) {
-        int kx = P._scope.kindx(var), fx = P._scope.enclosingFuncOrDecl();
+        int kx = P._scope.kindx(var);
         ScopeNode.Kind kind = P._scope._kinds.at(kx);
         if( !(kind instanceof Kind.Func inst) || !FunNode.isInstance(inst._name) || var._idx<inst._lexSize+2 ) return null;
-        if( kx==fx || kx+1==fx ) return defaultSelf();
+        // Nested functions have their own receiver parameter. Resolve fields
+        // through it even across intervening function and block scopes.
+        Node self = defaultSelf();
+        Type owner = P._scope.var(inst._lexSize).type();
+        if( self._type instanceof TypeMemPtr ptr && owner instanceof TypeMemPtr declared &&
+            ptr._obj._name.equals(declared._obj._name) ) return self;
         return null;
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/parser/Statements.java b/src/main/java/com/seaofnodes/simple/parser/Statements.java
index 707202ab..0c2a25f7 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Statements.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Statements.java
@@ -78,6 +78,7 @@ final class Statements {
      */
     private Node parseReturn() {
         var expr = P.require(P.expressions.parseAssignment(), ";");
+        if( P.arrays._frame!=null ) return P.arrays.addReturn(expr);
         return P.functions.addReturn(expr);
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/parser/Strings.java b/src/main/java/com/seaofnodes/simple/parser/Strings.java
index 5bf76585..be913371 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Strings.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Strings.java
@@ -32,7 +32,7 @@ final class Strings {
                 Node strings=P.references.member(text,"string",fmt.site()).keep();
                 fptr=new FormatNode(value,ints.unkeep(),floats.unkeep(),strings.unkeep(),fmt.site()).peephole();
             } else {
-                String family="diuoxXcb".indexOf(fmt.kind())>=0 ? "integer" : fmt.kind()=='s' ? "string" : "floating";
+                String family="diuoxXcb".indexOf(fmt.kind())>=0 ? "integer" : fmt.kind()=='s' ? "string" : fmt.kind()=='t' ? "time" : "floating";
                 fptr=P.references.member(text,family,fmt.site());
             }
             call(text,fptr,fmt.site(),builder,value.unkeep(),P.con(fmt.kind() | fmt.flags()<<8),
diff --git a/src/main/java/com/seaofnodes/simple/parser/Types.java b/src/main/java/com/seaofnodes/simple/parser/Types.java
index 827518fd..501924f0 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Types.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Types.java
@@ -37,6 +37,12 @@ final class Types {
             if( t0==Type.BOTTOM || t0==Type.TOP ) return t0; // var/val
             tname = typeName(tname).intern();
             t0 = Parser.TYPES.get(tname);
+            // Bare forward types use the same file-relative name as `new`.
+            // A later sibling declaration must complete this very type.
+            if( t0 == null && tname.indexOf('.') == -1 ) {
+                tname = fullTypeName(tname);
+                t0 = Parser.TYPES.get(tname);
+            }
         }
         Type t1 = t0==null ? TypeStruct.forward(tname) : t0;
 
@@ -135,9 +141,8 @@ final class Types {
 
     Type implicitSelfType() {
         TypeStruct self = P._scope.constructorSelf();
-        // Ordinary instance methods accept the declared object shape.  The
-        // constructor-only receiver starts at the low/default field values,
-        // and is built explicitly by parseConstructor().
+        // Function types without a body must allow for writes. Function
+        // expressions can infer a weaker requirement in MethodAccess.
         return self == null ? TypePtr.PTR : TypeMemPtr.make(self);
     }
 
diff --git a/src/main/java/com/seaofnodes/simple/parser/Var.java b/src/main/java/com/seaofnodes/simple/parser/Var.java
index ddbb91d8..5361148f 100644
--- a/src/main/java/com/seaofnodes/simple/parser/Var.java
+++ b/src/main/java/com/seaofnodes/simple/parser/Var.java
@@ -33,6 +33,11 @@ public class Var {
     public Type  type() { return _type; }
     public Type _type() { return _type; } // ScopeNode printer needs to have no side effects
 
+    void refineType(Type type) {
+        assert type.isa(_type) : _name+": "+_type+" -> "+type;
+        _type = type;
+    }
+
     // Forward reference variables (not types) must be BOTTOM and
     // distinct from inferred variables
     public boolean isFRef() { return _fref; }
diff --git a/src/main/java/com/seaofnodes/simple/parser/package-info.java b/src/main/java/com/seaofnodes/simple/parser/package-info.java
index c886f72a..73ebec2e 100644
--- a/src/main/java/com/seaofnodes/simple/parser/package-info.java
+++ b/src/main/java/com/seaofnodes/simple/parser/package-info.java
@@ -7,7 +7,7 @@
  * use-side name/field resolution; Allocations, ControlFlow, and Conversions
  * contain their shared IR construction. Lexer also supplies location snapshots.
  *
- * <p>See {@code chapter30/docs/30-grammar.md} for the production-to-method map.
+ * <p>See {@code chapter31/docs/31-grammar.md} for the production-to-method map.
  * Evaluation order and scope lifetimes are explicit: loop updates and declared
  * constructor bodies are the two deferred source fragments. There is no AST.
  */
diff --git a/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java b/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
index e8218afd..e4d1659d 100644
--- a/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
+++ b/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
@@ -10,19 +10,22 @@ import com.seaofnodes.simple.type.*;
 import java.util.ArrayList;
 import com.seaofnodes.simple.codegen.Encoding;
 import com.seaofnodes.simple.util.BAOS;
-import java.util.HashMap;
+import java.util.Map;
 
 /** Machine-specific facts; traversal, columns and byte display live in print/. */
 public final class ASMPrinter extends AssemblyAdapter<Node> {
     private final CodeGen _code;
     private final Encoding _enc;
-    private ASMPrinter(CodeGen code) {
+    private ASMPrinter(CodeGen code, Encoding enc) {
         super(new IRPrinter());
         _code=code;
-        _enc=code._encoding;
+        _enc=enc;
     }
     public static SB print(SB sb, CodeGen code) {
-        return sb.p(new com.seaofnodes.print.ASMPrinter<>(new ASMPrinter(code)).print());
+        return print(sb,code,code._encoding);
+    }
+    public static SB print(SB sb, CodeGen code, Encoding enc) {
+        return sb.p(new com.seaofnodes.print.ASMPrinter<>(new ASMPrinter(code,enc)).print());
     }
     @Override public ArrayList<Node> blocks() {
         var blocks=new ArrayList<Node>();
@@ -89,11 +92,11 @@ public final class ASMPrinter extends AssemblyAdapter<Node> {
         var data=new ArrayList<Data>();
         for( var obj : _enc._data.entries() )
             if( !obj.external && obj.readOnly==ro )
-                data.add(new Data(obj,obj.symbol+": "+obj.type.str(),obj.alignment,obj.size));
+                data.add(new Data(obj,obj.label()+": "+obj.type.str(),obj.alignment,obj.size));
         return data;
     }
     // Retain this diagnostic entry point for checking that pool printing never lays out types.
-    static int printConstantPool(int address, SB sb, BAOS bits, HashMap<Node,Encoding.Relo> relos,
+    static int printConstantPool(int address, SB sb, BAOS bits, Map<Node,Encoding.Relo> relos,
                                  boolean ro, String name) {
         sb.p(com.seaofnodes.print.ASMPrinter.pool(new Pool(name,bits.buf(),0,address,entries(relos.values(),ro))));
         return address+bits.size();
diff --git a/src/main/java/com/seaofnodes/simple/type/Type.java b/src/main/java/com/seaofnodes/simple/type/Type.java
index 0f655f49..2e228494 100644
--- a/src/main/java/com/seaofnodes/simple/type/Type.java
+++ b/src/main/java/com/seaofnodes/simple/type/Type.java
@@ -531,7 +531,7 @@ public class Type /*implements Cloneable*/ {
             // tag-space except for the first tag-space which uses 1 tag for
             // multiple Types instead of 1 Type having multiple tags.  Has to
             // be ordered to match _type enum.
-            for( Type t : new Type[]{Type.XNIL,TypeScalar.BOT,TypePtr.PTR,TypeInteger.BOT,TypeFloat.F64,TypeConAryB.ABC,TypeRPC.BOT,TypeMemPtr.BOT,TypeFunPtr.BOT,TypeMem.BOT,Field.BOT,TypeStruct.BOT,TypeTuple.BOT} )
+            for( Type t : new Type[]{Type.XNIL,TypeScalar.BOT,TypePtr.PTR,TypeInteger.BOT,TypeFloat.F64,TypeConAry.ABC,TypeRPC.BOT,TypeMemPtr.BOT,TypeFunPtr.BOT,TypeMem.BOT,Field.BOT,TypeStruct.BOT,TypeTuple.BOT} )
                 TAGOFFS[t._type+1] = TAGOFFS[t._type] + t.TAGOFF();
         assert TAGOFFS[TMAX] <= 255;
         return TAGOFFS;
diff --git a/src/main/java/com/seaofnodes/simple/type/TypeConAry.java b/src/main/java/com/seaofnodes/simple/type/TypeConAry.java
index 9cb23e09..c10f09aa 100644
--- a/src/main/java/com/seaofnodes/simple/type/TypeConAry.java
+++ b/src/main/java/com/seaofnodes/simple/type/TypeConAry.java
@@ -1,33 +1,48 @@
 package com.seaofnodes.simple.type;
 
 import com.seaofnodes.simple.util.BAOS;
-import com.seaofnodes.simple.util.Utils;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 
 /**
- * Represents a constant array of primitives
+ * Constant integer contents with an explicit storage width and signedness.
  */
-public abstract class TypeConAry<A> extends TypeScalar {
+public final class TypeConAry extends TypeScalar {
     boolean _any;
     byte _widen;
-    // One of byte or int array
-    public final A _ary;
+    private final TypeInteger _storage;
+    private final long[] _ary;
 
-    TypeConAry( boolean any, byte widen, A ary ) { super(TCONARY); _any = any; _widen = widen; _ary = ary; }
+    private TypeConAry(boolean any, byte widen, TypeInteger storage, long[] ary) {
+        super(TCONARY);
+        _any=any; _widen=widen; _storage=storage; _ary=ary;
+    }
+    static final TypeConAry ABC=make("abc");
+    static final TypeConAry ABCD=make("abcd");
     public static void gather(ArrayList<Type> ts) {
-        ts.add(TypeConAryB.make(""));
-        ts.add(TypeConAryB.ABC);
-        ts.add(TypeConAryB.ABCD);
-        ts.add(TypeConAryI.I123);
+        ts.add(make(""));
+        ts.add(ABC);
+        ts.add(ABCD);
+        ts.add(make(TypeInteger.I32,new long[]{1,2,3}));
+        ts.add(make(TypeInteger.U16,new long[]{0,65535}));
+        ts.add(make(TypeInteger.BOT,new long[]{Long.MIN_VALUE,Long.MAX_VALUE}));
+        for( TypeInteger storage : STORAGE ) {
+            ts.add(make(storage,new long[0]));
+            ts.add(make(storage,new long[]{0,1}));
+        }
     }
     // Fresh, uninterned type sharing this array; xdual must not intern.
-    abstract TypeConAry<A> _make(boolean any, byte widen);
+    private TypeConAry _make(boolean any, byte widen) {
+        return new TypeConAry(any,widen,_storage,_ary);
+    }
 
-    @Override TypeConAry<A> xdual() { return _make( !_any, (byte)(3-_widen) ); }
+    @Override TypeConAry xdual() { return _make( !_any, (byte)(3-_widen) ); }
 
     @Override Type xmeet(Type t) {
         TypeConAry ary = (TypeConAry)t; // Invariant
+        if( len()==0 ) return emptyMeet(ary);
+        if( ary.len()==0 ) return ary.emptyMeet(this);
         // Same base array but different?
         if( _equals(ary) )
             // Return array with larger widen
@@ -37,15 +52,7 @@ public abstract class TypeConAry<A> extends TypeScalar {
     }
 
     Type ymeet( TypeInteger ti ) {
-        // Empty arrays have no observed elements: use the storage bounds.
-        // Check both endpoints just as the loop checks a nonempty body;
-        // retaining high integer inputs here preserves lattice duality.
-        if( len()==0 ) {
-            TypeInteger bound=emptyElem();
-            if( !ti.isa(TypeInteger.make(bound._min,bound._min,ti._widen)) ||
-                !ti.isa(TypeInteger.make(bound._max,bound._max,ti._widen)) )
-                return ti.meet(bound);
-        }
+        if( len()==0 ) return emptyMeet(ti);
         // if i can isa *each* element, then maybe can keep.
         // no good to i.isa(elem()) because fails the dual
         for( int j=0; j<len(); j++ )
@@ -56,12 +63,21 @@ public abstract class TypeConAry<A> extends TypeScalar {
     }
 
     private boolean _equals(TypeConAry ary) {
-        int len = len();
-        if( len != ary.len() ) return false;
-        for( int i=0; i<len; i++ )
-            if( at8(i) != ary.at8(i) )
-                return false;
-        return true;
+        return _storage==ary._storage && (len()!=0 || _any==ary._any) && Arrays.equals(_ary,ary._ary);
+    }
+    @Override boolean eq(Type t) { return t instanceof TypeConAry ary && _widen==ary._widen && _equals(ary); }
+    @Override int hash() { return Arrays.hashCode(_ary)^_storage.hashCode()^(len()==0 && _any ? 1231 : 0); }
+    @Override public String str() {
+        boolean text=_storage==TypeInteger.U8;
+        for( long value : _ary )
+            if( value<32 || value>126 ) { text=false; break; }
+        if( !text ) {
+            String range=elem().str();
+            return range.startsWith("[") ? range : "["+range+"]";
+        }
+        byte[] bytes = new byte[len()];
+        for( int i=0; i<bytes.length; i++ ) bytes[i]=(byte)_ary[i];
+        return "[\""+new String(bytes)+"\"]";
     }
 
     @Override public boolean isHigh() { return this==TOP; }
@@ -70,8 +86,6 @@ public abstract class TypeConAry<A> extends TypeScalar {
 
     // Meet-over-elements type
     public Type elem() {
-        if( _ary==null )
-            return _any ? Type.TOP : BOTTOM;
         int len = len();
         long min = Long.MAX_VALUE;
         if( len==0 ) return emptyElem();
@@ -83,23 +97,80 @@ public abstract class TypeConAry<A> extends TypeScalar {
         return TypeInteger.make(min,max,_widen);
     }
     private TypeInteger emptyElem() {
-        return log_size()==0 ? TypeInteger.make(0,255,_widen)
-            : TypeInteger.make(Integer.MIN_VALUE,Integer.MAX_VALUE,_widen);
+        TypeInteger storage=storageType();
+        return _any ? TypeInteger.make(storage._min,storage._max,_widen)
+                    : TypeInteger.make(storage._max,storage._min,_widen);
+    }
+    // Keep the empty payload distinct from its element bound. It sits just
+    // above the storage dual; its own dual sits just below the storage bound.
+    // This makes it a subtype of every constant array within those bounds,
+    // while preserving meet/join symmetry with ordinary integer ranges.
+    private Type emptyMeet(Type t) {
+        Type bound=emptyElem();
+        if( t.isa(bound) && (_any || t!=bound) ) return this;
+        return bound.meet(t);
     }
-    public abstract long at8(int idx);
-    public abstract int len();
-    @Override public abstract int log_size();
-    public void write( BAOS baos ) { throw Utils.TODO("Should not reach here: abstract constant array cannot be written"); }
+    public TypeInteger storageType() { return _storage; }
+    public long at8(int idx) { return _ary[idx]; }
+    public int len() { return _ary.length; }
+    @Override public int log_size() { return _storage.log_size(); }
+    public void write( BAOS baos ) {
+        for( int i=0; i<len(); i++ ) {
+            long value=at8(i);
+            for( int b=0; b<(1<<log_size()); b++ ) baos.write((byte)(value >>> (8*b)));
+        }
+    }
+
+    /** Canonical contents, independent of the node which discovered them. */
+    public static TypeConAry make(TypeInteger storage, long[] values) {
+        long[] copy=values.clone();
+        int shift=64-(8<<storage.log_size());
+        for( int i=0; i<copy.length; i++ )
+            copy[i]=storage._min<0 ? (copy[i]<<shift)>>shift : copy[i]&storage._max;
+        return new TypeConAry(false,(byte)0,storage,copy).intern();
+    }
+    public static TypeConAry make(byte[] bytes) {
+        long[] values=new long[bytes.length];
+        for( int i=0; i<bytes.length; i++ ) values[i]=bytes[i]&255;
+        return new TypeConAry(false,(byte)0,TypeInteger.U8,values).intern();
+    }
+    public static TypeConAry make(String s) { return make(s.getBytes()); }
+
+    // Keep the existing byte-array tag and encoding. An impossible Java array
+    // length escapes to a typed payload, without renumbering later type tags.
+    private static final int TYPED = -1;
+    private static final TypeInteger[] STORAGE={TypeInteger.BOOL,TypeInteger.I8,TypeInteger.U8,
+        TypeInteger.I16,TypeInteger.U16,TypeInteger.I32,TypeInteger.U32,TypeInteger.BOT};
 
     // Reserve tags for u8 array
     @Override int TAGOFF() { return 1; }
     @Override public void packed( BAOS baos, HashMap<String,Integer> strs ) {
-        assert log_size()==0 && !_any;
         baos.write(TAGOFFS[TCONARY]+0);
+        if( storageType()!=TypeInteger.U8 || _any || _widen!=0 ) {
+            baos.packed4(TYPED);
+            int kind=0;
+            while( kind<STORAGE.length && STORAGE[kind]!=storageType() ) kind++;
+            assert kind<STORAGE.length;
+            baos.packed1(kind);
+            baos.packed1((_any ? 4 : 0)|_widen);
+        }
         baos.packed4(len());
-        baos.write((byte[])_ary);
+        write(baos);
     }
     static TypeConAry packed( int tag, BAOS bais ) {
-        return TypeConAryB.make(bais.read(new byte[bais.packed4()]));
+        int len=bais.packed4();
+        if( len!=TYPED ) return make(bais.read(new byte[len]));
+        TypeInteger storage=STORAGE[bais.packed1()];
+        int flags=bais.packed1();
+        long[] values=new long[bais.packed4()];
+        int size=1<<storage.log_size();
+        for( int i=0; i<values.length; i++ ) {
+            long value=0;
+            for( int b=0; b<size; b++ ) value|=(long)bais.read() << (8*b);
+            if( storage._min<0 && size<8 ) value=(value << (64-size*8)) >> (64-size*8);
+            values[i]=value;
+        }
+        TypeConAry ary=make(storage,values);
+        return flags==0 ? ary : ary._make((flags&4)!=0,(byte)(flags&3)).intern();
     }
 }
diff --git a/src/main/java/com/seaofnodes/simple/type/TypeConAryB.java b/src/main/java/com/seaofnodes/simple/type/TypeConAryB.java
deleted file mode 100644
index 84be5fb2..00000000
--- a/src/main/java/com/seaofnodes/simple/type/TypeConAryB.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import com.seaofnodes.simple.util.BAOS;
-import java.util.Arrays;
-
-public class TypeConAryB extends TypeConAry<byte[]> {
-    private TypeConAryB(boolean any, byte widen, byte[] bs) { super(any,widen,bs); }
-    @Override TypeConAryB _make( boolean any, byte widen ) { return new TypeConAryB(any,widen,_ary); }
-    public static TypeConAryB make( byte[] bs ) { return new TypeConAryB(false,(byte)0,bs).intern(); }
-    public static TypeConAryB make( String s ) { return make(s.getBytes()); }
-    static final TypeConAryB ABC  = make("abc");
-    static final TypeConAryB ABCD = make("abcd");
-    @Override public long at8(int idx) { return _ary[idx]&255; }
-    @Override public int len() { return _ary.length; }
-    @Override public int log_size() { return 0; }
-    @Override public String str() { return "[\""+new String(_ary)+"\"]"; }
-    @Override boolean eq(Type t) { return t instanceof TypeConAryB ary && _widen==ary._widen && Arrays.equals(_ary,ary._ary); }
-    @Override int hash() { return Arrays.hashCode(_ary); }
-    @Override public void write( BAOS baos ) { baos.write(_ary); }
-}
diff --git a/src/main/java/com/seaofnodes/simple/type/TypeConAryI.java b/src/main/java/com/seaofnodes/simple/type/TypeConAryI.java
deleted file mode 100644
index b1b061de..00000000
--- a/src/main/java/com/seaofnodes/simple/type/TypeConAryI.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package com.seaofnodes.simple.type;
-
-import java.util.Arrays;
-
-public class TypeConAryI extends TypeConAry<int[]> {
-    private TypeConAryI(boolean any, byte widen, int[] bs) { super(any,widen,bs); }
-    public static TypeConAryI make( int[] bs ) { return new TypeConAryI(false,(byte)0,bs).intern(); }
-    @Override TypeConAryI _make( boolean any, byte widen ) { return new TypeConAryI(any,widen,_ary); }
-    static final TypeConAryI I123 = make(new int[]{1,2,3});
-    @Override public long at8(int idx) { return _ary[idx]; }
-    @Override public int len() { return _ary.length; }
-    @Override public int log_size() { return 2; }
-    @Override public String str() { return "[i32]"; }
-    @Override boolean eq(Type t) { return t instanceof TypeConAryI ary && _widen==ary._widen && Arrays.equals(_ary,ary._ary); }
-    @Override int hash() { return Arrays.hashCode(_ary); }
-}
diff --git a/src/main/java/com/seaofnodes/simple/type/TypeFloat.java b/src/main/java/com/seaofnodes/simple/type/TypeFloat.java
index d410e9cf..8d04fcbf 100644
--- a/src/main/java/com/seaofnodes/simple/type/TypeFloat.java
+++ b/src/main/java/com/seaofnodes/simple/type/TypeFloat.java
@@ -107,7 +107,7 @@ public class TypeFloat extends TypeScalar {
         else {
             assert isConstant();
             baos.write(TAGOFFS[_type] + 2);
-            baos.packed8(Double.doubleToLongBits(_con));
+            baos.packed8(Double.doubleToRawLongBits(_con));
         }
     }
 
@@ -121,12 +121,12 @@ public class TypeFloat extends TypeScalar {
     }
 
     @Override
-    int hash() { return (int)(Double.hashCode(_con) ^ _sz ^ (1<<17)); }
+    int hash() { return Long.hashCode(Double.doubleToRawLongBits(_con)) ^ _sz ^ (1<<17); }
     @Override
     public boolean eq( Type t ) {
         TypeFloat i = (TypeFloat)t; // Contract
-        // Allow NaN to check for equality
-        return _sz==i._sz && Double.doubleToLongBits(_con)==Double.doubleToLongBits(i._con);
+        // Representation conversions observe NaN signs/payloads and signed zero.
+        return _sz==i._sz && Double.doubleToRawLongBits(_con)==Double.doubleToRawLongBits(i._con);
     }
 
 }
diff --git a/src/main/java/com/seaofnodes/simple/type/TypeMem.java b/src/main/java/com/seaofnodes/simple/type/TypeMem.java
index 5faa7107..1c83ddd7 100644
--- a/src/main/java/com/seaofnodes/simple/type/TypeMem.java
+++ b/src/main/java/com/seaofnodes/simple/type/TypeMem.java
@@ -211,14 +211,19 @@ public class TypeMem extends Type {
                    + (!_one     ? 0 : (_clz ? 4 : 8)));
         if( _alias!=1 ) {
             // generic alias
-            assert _alias <= 255;
-            baos.packed1( _alias );
+            // Zero is reserved for alias-set flags, never a memory slice.
+            // Use it as an escape for large libraries, retaining the existing
+            // single-byte encoding (including 255) for older objects.
+            assert _alias>1;
+            baos.packed1(_alias<=255 ? _alias : 0);
+            if( _alias>255 ) baos.packed4(_alias);
         }
         XInt.packed(baos,_escFs);
         XInt.packed(baos,_escAs);
     }
     static TypeMem packed( int tag, BAOS bais ) {
         int alias = (tag&1)==0 ? 1 : bais.packed1();
+        if( alias==0 ) alias=bais.packed4();
         boolean xfinal= (tag&2)==2;
         boolean one   = (tag&12)!=0;
         boolean clz   = (tag&4)==4;
diff --git a/src/main/java/com/seaofnodes/simple/type/TypeStruct.java b/src/main/java/com/seaofnodes/simple/type/TypeStruct.java
index 7c9758bd..11ba3cc4 100644
--- a/src/main/java/com/seaofnodes/simple/type/TypeStruct.java
+++ b/src/main/java/com/seaofnodes/simple/type/TypeStruct.java
@@ -146,8 +146,7 @@ public class TypeStruct extends Type {
         Type len = TypeInteger.constant(con.len());
         return make(name,false,
                     Field.make("#"    ,len       , lenAlias,true),
-                    Field.make("[]"   ,con.elem(),bodyAlias,true),
-                    Field.make("[con]",con       ,bodyAlias,true));
+                    Field.make("[]"   ,con       ,bodyAlias,true));
     }
 
     public TypeStruct makeInit() {
@@ -190,6 +189,9 @@ public class TypeStruct extends Type {
     }
     @Override TypeStruct _close( String name, HashMap<String, Type> TYPES ) {
         assert (name==null) != (TYPES==null); // One or the other
+        // Primitive constant contents are already closed. Looking up their
+        // shared array name would discard the length and payload on import.
+        if( isConAry() ) return this;
         String namePlusFinal = isAry() ? (_name+(_fields[1]._final ? "~" : "!")).intern() : _name;
         TypeStruct ts = (TypeStruct)VISIT.get(namePlusFinal);
         if( ts!=null ) return ts;
@@ -251,7 +253,7 @@ public class TypeStruct extends Type {
     public  static final TypeStruct TEST= make("test",false,Field.TEST);
     private static final TypeStruct ARY = makeAry("[]i64",TypeInteger.U32,-1,TypeInteger.BOT,-2,false);
     private static final TypeStruct STR = makeAry("[]u8" ,TypeInteger.U32,-1,TypeInteger.U8 ,-4,false);
-    private static final TypeStruct ABC = makeAry("[]u8",-1,-4,TypeConAryB.ABC);
+    private static final TypeStruct ABC = makeAry("[]u8",-1,-4,TypeConAry.ABC);
     // Representative unresolved forms for the exhaustive lattice tests:
     // bare forward ref, forward ref constrained by a field use, and definition.
     private static final TypeStruct FREF0 = forward("%FREF");
@@ -462,6 +464,7 @@ public class TypeStruct extends Type {
     @Override public int log_size() { throw Utils.TODO("Should not reach here: structs have no scalar log size"); }
     @Override public int size() { return offset(_fields.length); }
     @Override public int alignment() {
+        if( isAry() ) return Math.max(2,aryScale()); // The length is always u32.
         int align = 0;
         for( Field f : _fields )
             if( !f._extern ) align = Math.max(align, f._t.alignment());
@@ -607,7 +610,7 @@ public class TypeStruct extends Type {
             int align = _fields[1]._t.alignment();
             _offs[1] = (4 + ((1<<align)-1)) & -(1<<align);
             if( _fields[1]._t instanceof TypeConAry ary ) // Array length is well-defined for constants, not defined for runtime arrays
-                _offs[2] = _offs[1]+ary.len();
+                _offs[2] = _offs[1]+(ary.len()<<ary.log_size());
 
         } else {
             int[] cnts = new int[5]; // Count of fields at log field size
diff --git a/src/main/smp/sys.smp b/src/main/smp/sys.smp
index 1201315b..3fb8d94b 100644
--- a/src/main/smp/sys.smp
+++ b/src/main/smp/sys.smp
@@ -2,12 +2,18 @@
 // top-level default standard library import
 
 val adt = adt;                  // Abstract Data Types
+val audio = audio;              // Optional background sound (miniaudio)
 val ary = ary;                  // Array utilities
 val aryi64 = aryi64;            // Variable sized array of i64
 val aryu8 = aryu8;              // Variable sized array of u8
 val char = char;                // Character utilities
+val integer = integer;          // Integer bounds
+val math = math;                // Floating-point representation primitives
 val io = io;                    // IO library
+val gfx = gfx;                  // Optional pixel window (MiniFB)
+val draw = draw;                // Software raster drawing in Simple
 val text = text;                // Typed text conversions
+val time = time;                // Clocks, calendar text, and cooperative timers
 val libc = libc;                // libc FFI bindings
 val rt = rt;                    // Run Time support
 val scan = scan;                // A simple string parser
diff --git a/src/main/smp/sys/adt/bitset.smp b/src/main/smp/sys/adt/bitset.smp
index d02cd2fe..a51a63e1 100644
--- a/src/main/smp/sys/adt/bitset.smp
+++ b/src/main/smp/sys/adt/bitset.smp
@@ -20,7 +20,7 @@ struct bitset {
         if( x < len ) return self;
         while( x >= len ) len *= 2;
         var bits = new i64[len];
-        for( int i=0; i<_bits#; i++ )
+        for( int i = 0; i < _bits#; i++ )
             bits[i] = _bits[i];
         _bits = bits;
         return self;
@@ -51,7 +51,7 @@ struct bitset {
     };
 
     val clear = { ->
-        for( int i=0; i<_bits#; i++ ) _bits[i] = 0;
+        for( int i = 0; i < _bits#; i++ ) _bits[i] = 0;
         return self;
     };
 };
diff --git a/src/main/smp/sys/ary.smp b/src/main/smp/sys/ary.smp
index c139cd33..b94ffa8f 100644
--- a/src/main/smp/sys/ary.smp
+++ b/src/main/smp/sys/ary.smp
@@ -3,12 +3,12 @@
 
 // Geometric growth without wrapping a u32 length. Zero means too large.
 val capacity = { u32 current, i64 needed ->
-    if( needed < 0 || needed > 4294967295 ) return 0;
+    if( needed < 0 || needed > sys.integer.MAX_U32 ) return 0;
     if( needed <= current ) return current;
     i64 size = current ? current : 1;
     while( size < needed ) {
         size *= 2;
-        if( size > 4294967295 ) size = 4294967295;
+        if( size > sys.integer.MAX_U32 ) size = sys.integer.MAX_U32;
     }
     u32 result = size;
     return result;
@@ -19,7 +19,7 @@ val copy = { u8[] dst, u32 doff, u8[~] src, u32 soff, u32 len ->
     if( doff > dst# || soff > src# ) return dst;
     if( len > dst# - doff ) len = dst# - doff;
     if( len > src# - soff ) len = src# - soff;
-    for( u32 i=0; i<len; i++ )
+    for( u32 i = 0; i < len; i++ )
         dst[i+doff] = src[i+soff];
     return dst;
 };
@@ -33,7 +33,7 @@ val cmp = { u8[~] src1, u32 off1, u8[~] src2, u32 off2, u32 len ->
     u32 len1 = len > left1 ? left1 : len;
     u32 len2 = len > left2 ? left2 : len;
     u32 max = len1 > len2 ? len2 : len1;
-    for( u32 i=0; i<max; i++ )
+    for( u32 i = 0; i < max; i++ )
         if( src1[off1+i] != src2[off2+i] )
             return src1[off1+i] - src2[off2+i]; // Bytes determine compare
     return len1 - len2;                         // Length determines compare
diff --git a/src/main/smp/sys/aryi64.smp b/src/main/smp/sys/aryi64.smp
index b9f1fbed..aba1b459 100644
--- a/src/main/smp/sys/aryi64.smp
+++ b/src/main/smp/sys/aryi64.smp
@@ -14,7 +14,7 @@ struct aryi64 {
         u32 newlen = ary.capacity(buf#,len+len2);
         if( !newlen ) libc._exit(1); // Length exceeds the array representation.
         i64[] !buf2 = new i64[newlen];
-        for( u32 i=0; i<len; i++ )
+        for( u32 i = 0; i < len; i++ )
             buf2[i] = buf[i];
         buf = buf2;
         self;
@@ -32,7 +32,7 @@ struct aryi64 {
     val str = { ->
         // TODO: clunky default constructor syntax
         var str = new aryu8().add('[');
-        for( u32 i=0; i<len; i++ )
+        for( u32 i = 0; i < len; i++ )
             str.num(buf[i]).add(',').add(' ');
         if( len ) str.undo(2);
         return str.add(']');
@@ -79,7 +79,7 @@ val copy = { i64[] dst, u32 doff, i64[~] src, u32 soff, u32 len ->
     if( doff > dst# || soff > src# ) return dst;
     if( len > dst# - doff ) len = dst# - doff;
     if( len > src# - soff ) len = src# - soff;
-    for( u32 i=0; i<len; i++ )
+    for( u32 i = 0; i < len; i++ )
         dst[i+doff] = src[i+soff];
     return dst;
 };
diff --git a/src/main/smp/sys/aryu8.smp b/src/main/smp/sys/aryu8.smp
index 18543f13..3f462898 100644
--- a/src/main/smp/sys/aryu8.smp
+++ b/src/main/smp/sys/aryu8.smp
@@ -27,7 +27,7 @@ struct aryu8 {
 
     // Add all of a plain array to the aryu8
     val addAry = { u8[~] xs ->
-        u32 n=xs#;
+        u32 n = xs#;
         _grow(n);
         ary.copy(buf,len,xs,0,n);
         len += n;
@@ -60,7 +60,7 @@ val atoi = { u8[~] str ->
     while( x < str# && str[x] <= ' ' ) x++;
     if( x == str# ) return 0;
     bool neg = false;
-    if( str[x]=='-' ) { neg=true; x++; }
+    if( str[x] == '-' ) { neg = true; x++; }
     i64 n = 0;
     while( x < str# && '0' <= str[x] <= '9' )
         n = n*10 + str[x++]-'0';
@@ -69,10 +69,7 @@ val atoi = { u8[~] str ->
 
 // Zero-terminate a string for libc, reserving one array element for the zero.
 { u8[~] -> u8[] } str0 = { u8[~] str ->
-  if( str# == 4294967295 ) libc._exit(1);
-  u8[] !strz = new u8[str#+1];
-  u32 len=str#;
-  ary.copy(strz,0,str,0,len);
-  strz[str#] = '\0';
-  strz;
+    if( str# == sys.integer.MAX_U32 ) libc._exit(1);
+    // Copy, terminate and return
+    return new u8[str#+1]{i64 i -> i < str# ? str[i] : '\0'; };
 };
diff --git a/src/main/smp/sys/audio.smp b/src/main/smp/sys/audio.smp
new file mode 100644
index 00000000..89e6dfa9
--- /dev/null
+++ b/src/main/smp/sys/audio.smp
@@ -0,0 +1,29 @@
+// Optional background audio. All API calls belong on the game/main thread.
+int OK = 0;
+int ERROR = -1;
+int BOOP = 1;
+int WIN = 2;
+int LOSE = 3;
+int RATE = 48000;
+{ i32 } simple_audio_open = "C";
+{ i64 u32 -> i32 } simple_audio_load = "C";
+{ i32 -> i32 } simple_audio_play = "C";
+{ i32 } simple_audio_stop = "C";
+{ i32 } simple_audio_playing = "C";
+{ i32 } simple_audio_close = "C";
+// Missing/disabled backend returns ERROR quietly; the game may remain silent.
+val open = { -> simple_audio_open(); };
+// Mono signed 16-bit PCM at RATE, up to ten seconds. Copies into native memory.
+// Load at startup: up to 28 custom handles, valid until close, then reload.
+val load = { i16[~] samples ->
+    i64 ptr = samples;
+    simple_audio_load(ptr,samples#);
+};
+// Starts/restarts immediately, replacing the previous sound; never waits for it.
+val play = { int sound -> simple_audio_play(sound); };
+val boop = { -> simple_audio_play(BOOP); };
+val win = { -> simple_audio_play(WIN); };
+val lose = { -> simple_audio_play(LOSE); };
+val stop = { -> simple_audio_stop(); };
+val playing = { -> simple_audio_playing(); };
+val close = { -> simple_audio_close(); };
diff --git a/src/main/smp/sys/draw.smp b/src/main/smp/sys/draw.smp
new file mode 100644
index 00000000..2a8b6117
--- /dev/null
+++ b/src/main/smp/sys/draw.smp
@@ -0,0 +1,18 @@
+// Software raster drawing. No window or native calls; pixels are packed RGB (0x00RRGGBB).
+u32 BLACK = 0x000000;
+u32 WHITE = 0xffffff;
+u32 RED   = 0xff0000;
+u32 GREEN = 0x00ff00;
+u32 BLUE  = 0x0000ff;
+
+// Components are clamped to bytes rather than wrapping.
+val rgb = { int r, int g, int b ->
+    r = r < 0 ? 0 : r > 255 ? 255 : r;
+    g = g < 0 ? 0 : g > 255 ? 255 : g;
+    b = b < 0 ? 0 : b > 255 ? 255 : b;
+    u32 color = (r<<16) | (g<<8) | b;
+    return color;
+};
+
+val Canvas = Canvas; // Pixel canvas and drawing methods
+val Button = Button; // Pointer state and rendering for a rectangular button
diff --git a/src/main/smp/sys/draw/Button.smp b/src/main/smp/sys/draw/Button.smp
new file mode 100644
index 00000000..c90ed2d3
--- /dev/null
+++ b/src/main/smp/sys/draw/Button.smp
@@ -0,0 +1,41 @@
+// Feed pointer state once per event-loop iteration. Activate on release inside,
+// only after a press that began inside. No native/window dependency.
+struct Button {
+    int x, y, width, height;
+    u8[~] !label;
+    bool !enabled = true, !hovered = false, !pressed = false;
+    bool !_held = false, !_armed = false;
+    new Button = { int px, int py, int w, int h, u8[~] text ->
+        x = px; y = py; width = w; height = h; label = text;
+    };
+    val contains = { i64 px, i64 py ->
+        if( width <= 0 || height <= 0 ) return false;
+        i64 right = x, bottom = y; right += width; bottom += height;
+        if( px < x || py < y || px >= right || py >= bottom ) return false;
+        return true;
+    };
+    val update = { i64 px, i64 py, bool down ->
+        hovered = false;
+        if( enabled ) hovered = contains(px,py);
+        if( !enabled ) _armed = false;
+        if( down && !_held ) _armed = hovered;
+        var clicked = false;
+        if( !down ) if( _held ) if( _armed ) if( hovered ) clicked = true;
+        if( !down ) _armed = false;
+        _held = down;
+        pressed = false;
+        if( down ) if( _armed ) if( hovered ) pressed = true;
+        return clicked;
+    };
+    val draw = { !sys.draw.Canvas screen, int scale, u32 foreground, u32 background, u32 active ->
+        screen.fillRect(x,y,width,height,enabled && (hovered || pressed) ? active : background);
+        screen.rect(x,y,width,height,2,enabled ? foreground : active);
+        if( scale > 0 ) {
+            i64 textWidth = label#; textWidth = (textWidth*4-1)*scale;
+            if( textWidth <= width-8 && 5*scale <= height-8 )
+                screen.text(x+(width-textWidth)/2,y+(height-5*scale)/2+(pressed ? 1 : 0),
+                    label,scale,enabled ? foreground : active);
+        }
+        return self;
+    };
+};
diff --git a/src/main/smp/sys/draw/Canvas.smp b/src/main/smp/sys/draw/Canvas.smp
new file mode 100644
index 00000000..9ba3514a
--- /dev/null
+++ b/src/main/smp/sys/draw/Canvas.smp
@@ -0,0 +1,149 @@
+struct Canvas {
+    u32 width;
+    u32 height;
+    u32[] pixels;
+
+    new Canvas = { u32 w, u32 h ->
+        i64 count = w;
+        count *= h;
+        if( w <= 0 || h <= 0 || count > sys.integer.MAX_I32 ) libc._exit(1);
+        width = w;
+        height = h;
+        pixels = new u32[count];
+    };
+
+    val clear = { u32 color ->
+        for( int i = 0; i < pixels#; i++ ) pixels[i] = color;
+        return self;
+    };
+
+    val pixel = { i64 x, i64 y, u32 color ->
+        if( 0 <= x < width && 0 <= y < height ) pixels[y*width+x] = color;
+        return self;
+    };
+
+    // Integer coordinates, top-left origin. Rectangle extents are half-open.
+    val fillRect = { i64 x, i64 y, i64 w, i64 h, u32 color ->
+        if( w <= 0 || h <= 0 ) return self;
+        i64 right = x; right += w;
+        i64 bottom = y; bottom += h;
+        if( right <= 0 || bottom <= 0 || x >= width || y >= height ) return self;
+        int x0 = x < 0 ? 0 : x, y0 = y < 0 ? 0 : y;
+        int x1 = right > width ? width : right, y1 = bottom > height ? height : bottom;
+        for( int py = y0; py < y1; py++ )
+            for( int px = x0; px < x1; px++ ) pixels[py*width+px] = color;
+        return self;
+    };
+
+    // Outline stays inside the rectangle. Wide borders become a filled rect.
+    val rect = { i64 x, i64 y, i64 w, i64 h, i64 thickness, u32 color ->
+        if( w <= 0 || h <= 0 || thickness <= 0 ) return self;
+        if( thickness >= w || thickness >= h || thickness >= w-thickness || thickness >= h-thickness )
+            return fillRect(x,y,w,h,color);
+        fillRect(x,y,w,thickness,color);
+        fillRect(x,y+h-thickness,w,thickness,color);
+        fillRect(x,y+thickness,thickness,h-2*thickness,color);
+        return fillRect(x+w-thickness,y+thickness,thickness,h-2*thickness,color);
+    };
+
+    // Integer centers are pixel centers. Circle outlines extend inward.
+    val fillCircle = { i64 cx, i64 cy, int radius, u32 color ->
+        return _circle(cx,cy,radius,0,true,color);
+    };
+    val circle = { i64 cx, i64 cy, int radius, int thickness, u32 color ->
+        return _circle(cx,cy,radius,thickness,false,color);
+    };
+    val _circle = { i64 cx, i64 cy, int radius, int thickness, bool filled, u32 color ->
+        if( radius < 0 || (!filled && thickness <= 0) ) return self;
+        i64 left = cx; left -= radius;
+        i64 top = cy; top -= radius;
+        i64 right = cx; right += radius;
+        i64 bottom = cy; bottom += radius;
+        if( right < 0 || bottom < 0 || left >= width || top >= height ) return self;
+        int x0 = left < 0 ? 0 : left, y0 = top < 0 ? 0 : top;
+        int x1 = right >= width ? width-1 : right, y1 = bottom >= height ? height-1 : bottom;
+        i64 outer2 = radius;
+        outer2 *= radius;
+        i64 inner = filled ? -1 : radius-thickness;
+        for( int py = y0; py <= y1; py++ )
+            for( int px = x0; px <= x1; px++ ) {
+                i64 dx = px; dx -= cx;
+                i64 dy = py; dy -= cy;
+                i64 d2 = dx*dx+dy*dy;
+                if( d2 <= outer2 && (inner <= 0 || d2 > inner*inner) ) pixels[py*width+px] = color;
+            }
+        return self;
+    };
+
+    // Round caps; a zero-length segment is a dot. Only the clipped bounding
+    // box is scanned. Floating distances avoid overflowing coordinate squares.
+    val line = { i64 x0, i64 y0, i64 x1, i64 y1, i64 thickness, u32 color ->
+        if( thickness <= 0 ) return self;
+        i64 pad = thickness/2+1;
+        i64 left = x0 < x1 ? x0 : x1; left -= pad;
+        i64 top = y0 < y1 ? y0 : y1; top -= pad;
+        i64 right = x0 > x1 ? x0 : x1; right += pad;
+        i64 bottom = y0 > y1 ? y0 : y1; bottom += pad;
+        if( right < 0 || bottom < 0 || left >= width || top >= height ) return self;
+        int bx0 = left < 0 ? 0 : left, by0 = top < 0 ? 0 : top;
+        int bx1 = right >= width ? width-1 : right, by1 = bottom >= height ? height-1 : bottom;
+        for( int py = by0; py <= by1; py++ )
+            for( int px = bx0; px <= bx1; px++ )
+                if( _onLine(px,py,x0,y0,x1,y1,thickness) ) pixels[py*width+px] = color;
+        return self;
+    };
+
+    // Small 3x5 bitmap font for game labels. Lowercase maps to uppercase.
+    // Newline returns to x; unsupported characters draw a question mark.
+    val text = { i64 x, i64 y, u8[~] str, int scale, u32 color ->
+        if( scale <= 0 ) return self;
+        i64 px = x, py = y;
+        for( int i = 0; i < str#; i++ ) {
+            u8 c = str[i];
+            if( c == '\n' ) { px = x; py += 6*scale; continue; }
+            int bits = _glyph(c);
+            for( int row = 0; row < 5; row++ )
+                for( int col = 0; col < 3; col++ )
+                    if( (bits >> (14-row*3-col)) & 1 )
+                        fillRect(px+col*scale,py+row*scale,scale,scale,color);
+            px += 4*scale;
+        }
+        return self;
+    };
+};
+
+// An old-school 3x5 font, ASCII 32..127. Five octal row digits need u16.
+// Lowercase uses uppercase shapes; unsupported characters use '?'.
+val _glyphs = new u16[~96]{
+    000000,022202,055000,057575,061202,051245,061202,022000, // space..'
+    012221,042224,005250,002720,000024,000700,000002,011244, // (../
+    075557,026227,061247,061216,055711,074616,034757,071222, // 0..7
+    075757,075716,002020,002024,012421,007070,042124,061202, // 8..?
+    061202,025755,065656,034443,065556,074647,074644,034553, // @..G
+    055755,072227,011152,055655,044447,057755,057775,025552, // H..O
+    065644,025573,065655,034216,072222,055557,055552,055775, // P..W
+    055255,055222,071247,032223,044211,062226,025000,000007, // X.._
+    042000,025755,065656,034443,065556,074647,074644,034553, // `..g
+    055755,072227,011152,055655,044447,057755,057775,025552, // h..o
+    065644,025573,065655,034216,072222,055557,055552,055775, // p..w
+    055255,055222,071247,032423,022222,062126,003600,061202, // x..DEL
+};
+
+val _glyph = { u8 c ->
+    return 32 <= c < 128 ? _glyphs[c-32] : 061202;
+};
+
+// Pixel coverage for a round-ended segment, separate from traversal.
+val _onLine = { i64 px, i64 py, i64 x0, i64 y0, i64 x1, i64 y1, i64 thickness ->
+    f64 dx = x1; dx -= x0;
+    f64 dy = y1; dy -= y0;
+    f64 vx = px; vx -= x0;
+    f64 vy = py; vy -= y0;
+    f64 length2 = dx*dx+dy*dy;
+    bool point = x0 == x1 && y0 == y1;
+    f64 t = point ? 0.0 : (vx*dx+vy*dy)/length2;
+    t = t < 0 ? 0.0 : t > 1 ? 1.0 : t;
+    f64 ex = vx-t*dx, ey = vy-t*dy;
+    f64 half = thickness/2.0;
+    return ex*ex+ey*ey <= half*half;
+};
diff --git a/src/main/smp/sys/gfx.smp b/src/main/smp/sys/gfx.smp
new file mode 100644
index 00000000..ae203bd1
--- /dev/null
+++ b/src/main/smp/sys/gfx.smp
@@ -0,0 +1,44 @@
+// Minimal pixel-window interface; drawing belongs in Simple.
+// One fixed-size window, main thread only. Pixel format is 0x00RRGGBB.
+// open/present/poll return OK, CLOSED (normal user close/Esc), or ERROR.
+int OK = 0;
+int CLOSED = 1;
+int ERROR = -1;
+int LEFT = 1;
+int ESCAPE = 256;
+
+{ i64 u32 u32 -> i32 } simple_gfx_open = "C";
+{ i64 u32 -> i32 } simple_gfx_present = "C";
+{ i32 -> i32 } simple_gfx_poll = "C";
+{ i32 } simple_gfx_mouse_x = "C";
+{ i32 } simple_gfx_mouse_y = "C";
+{ i32 -> i32 } simple_gfx_button = "C";
+{ i32 -> i32 } simple_gfx_key = "C";
+{ i32 } simple_gfx_close = "C";
+{ i64 -> i32 } simple_gfx_wait = "C";
+
+// Failure prints a diagnostic to stderr and returns ERROR; callers decide
+// whether to exit or fall back to text. No native library is loaded until here.
+val open = { u8[~] title, u32 width, u32 height ->
+    i64 ptr = aryu8.str0(title);
+    simple_gfx_open(ptr,width,height);
+};
+
+// Array length must be width*height. The native layer copies for OS repaints;
+// it never keeps a pointer into the Simple heap after this call returns.
+val present = { u32[~] pixels ->
+    i64 ptr = pixels;
+    simple_gfx_present(ptr,pixels#);
+};
+
+// wait=true waits up to 17ms, waking early for input to avoid a busy loop.
+val poll = { bool wait -> simple_gfx_poll(wait); };
+val mouseX = { -> simple_gfx_mouse_x(); };
+val mouseY = { -> simple_gfx_mouse_y(); };
+val button = { int button -> simple_gfx_button(button); };
+// Printable keys use uppercase ASCII; special keys use MiniFB's key codes.
+val key = { int key -> simple_gfx_key(key); };
+val close = { -> simple_gfx_close(); };
+// Wait for input or at most timeout milliseconds; 0 polls, -1 waits indefinitely.
+// This blocks the game thread, dispatches window events, and may wake early.
+val wait = { i64 timeout_ms -> simple_gfx_wait(timeout_ms); };
diff --git a/src/main/smp/sys/integer.smp b/src/main/smp/sys/integer.smp
new file mode 100644
index 00000000..a839e597
--- /dev/null
+++ b/src/main/smp/sys/integer.smp
@@ -0,0 +1,6 @@
+// Integer bounds.
+
+i64 MIN_I64 = 1<<63;
+i64 MAX_I64 = -(MIN_I64+1);
+i32 MAX_I32 = (1<<31)-1;
+u32 MAX_U32 = (1<<32)-1;
diff --git a/src/main/smp/sys/io.smp b/src/main/smp/sys/io.smp
index 14993429..6269cde5 100644
--- a/src/main/smp/sys/io.smp
+++ b/src/main/smp/sys/io.smp
@@ -21,7 +21,7 @@ val read = { i32 fd ->
             return null;
         }
         if( rez == 0 ) break;
-        if( buf.len+rez > 4294967295 ) {
+        if( buf.len+rez > sys.integer.MAX_U32 ) {
             libc.set_errno(libc.EOVERFLOW);
             return null;
         }
diff --git a/src/main/smp/sys/libc.smp b/src/main/smp/sys/libc.smp
index 7122bbd8..8e417461 100644
--- a/src/main/smp/sys/libc.smp
+++ b/src/main/smp/sys/libc.smp
@@ -53,9 +53,9 @@ i32 EOVERFLOW = "C";
 // addr len prot flags fd  off -> void*
 {  i64  i64 i32  i32   i32 i32 -> i64 } mmap = "C";
 // mmap flags
-i32 PROT_EXEC = 4;
-i32 PROT_READ = 1;
-i32 PROT_WRITE= 2;
-i32 PROT_NONE = 0;
+i32 PROT_EXEC  = 4;
+i32 PROT_READ  = 1;
+i32 PROT_WRITE = 2;
+i32 PROT_NONE  = 0;
 i32 MAP_PRIVATE = 2;
 i32 MAP_ANON = 32;
diff --git a/src/main/smp/sys/math.smp b/src/main/smp/sys/math.smp
new file mode 100644
index 00000000..a5e1887c
--- /dev/null
+++ b/src/main/smp/sys/math.smp
@@ -0,0 +1,15 @@
+// Mathematical constants, rounded to the nearest f64 value.
+val PI = 3.141592653589793;
+val E  = 2.718281828459045;
+
+// Fixed-semantics C bindings recognized by the compiler's intrinsic inliner.
+// These preserve all 64 bits, including signed zero and NaN payloads.
+// They are NOT numeric conversions (ordinary typed assignments still are).
+{ f64 -> i64 } simple_f64_bits = "C";
+{ i64 -> f64 } simple_f64_from_bits = "C";
+val f64Bits = simple_f64_bits;
+val f64FromBits = simple_f64_from_bits;
+
+
+val max = { f64 x, f64 y -> return x > y ? x : y; };
+val min = { f64 x, f64 y -> return x < y ? x : y; };
diff --git a/src/main/smp/sys/rt/simple_args.smp b/src/main/smp/sys/rt/simple_args.smp
index 3f630e54..8bfcc1a7 100644
--- a/src/main/smp/sys/rt/simple_args.smp
+++ b/src/main/smp/sys/rt/simple_args.smp
@@ -1,18 +1,20 @@
 // Native startup support, compiled independently and linked with the CRT.
 // Raw native addresses stay i64; only the arrays allocated here are Simple objects.
+// This startup object is built without sys imports.
+u32 _MAX_U32 = (1<<32)-1;
 { i64 i64 -> i64 } simple_argv = "C";
 { i64 -> i64 } strlen = "C";
 { i64 i64 i64 -> i64 } memcpy = "C";
 
 val simple_args = { i64 argc, i64 argv ->
-    if( argc < 0 || argc > 4294967295 ) return null;
+    if( argc < 0 || argc > _MAX_U32 ) return null;
     // Zero-filled reference arrays require nullable elements. Every slot is
     // filled before returning; the native entry bridge publishes u8[~][].
     val args = new u8[~]?[argc];
-    for( i64 i=0; i<argc; i++ ) {
+    for( i64 i = 0; i < argc; i++ ) {
         i64 src = simple_argv(argv,i);
         i64 len = strlen(src);
-        if( len < 0 || len > 4294967295 ) return null;
+        if( len < 0 || len > _MAX_U32 ) return null;
         val bytes = new u8[len];
         i64 dst = bytes;
         memcpy(dst,src,len);
diff --git a/src/main/smp/sys/text.smp b/src/main/smp/sys/text.smp
index a414ff45..43698f22 100644
--- a/src/main/smp/sys/text.smp
+++ b/src/main/smp/sys/text.smp
@@ -5,78 +5,75 @@
 val begin = { -> new aryu8(); };
 
 val end = { aryu8 b ->
-    val bytes = new u8[b.len];
-    ary.copy(bytes,0,b.buf,0,b.len);
-    u8[~] result = bytes;
-    result;
+    new u8[~b.len]{ i64 i -> b.buf[i]; };
 };
 
 val _pad = { !aryu8 b, i64 n, u8 c ->
-    for( i64 i=0; i<n; i++ ) b.add(c);
+    for( i64 i = 0; i < n; i++ ) b.add(c);
     b;
 };
 
 val string = { !aryu8 b, u8[~] s, i64 spec, i64 width, i64 precision ->
-    i64 len=s#;
-    if( precision>=0 && precision<len ) len=precision;
-    i64 pad=width-len;
+    i64 len = s#;
+    if( precision >= 0 && precision < len ) len = precision;
+    i64 pad = width-len;
     if( !(spec&256) ) _pad(b,pad,' ');
-    for( i64 i=0; i<len; i++ ) b.add(s[i]);
+    for( i64 i = 0; i < len; i++ ) b.add(s[i]);
     if( spec&256 ) _pad(b,pad,' ');
     b;
 };
 
 val integer = { !aryu8 b, i64 value, i64 spec, i64 width, i64 precision ->
-    i64 kind=spec&255;
-    if( kind=='b' ) return string(b,value ? "true" : "false",spec,width,-1);
-    if( kind=='c' ) {
+    i64 kind = spec&255;
+    if( kind == 'b' ) return string(b,value ? "true" : "false",spec,width,-1);
+    if( kind == 'c' ) {
         if( !(spec&256) ) _pad(b,width-1,' ');
-        u8 c=value;
+        u8 c = value;
         b.add(c);
         if( spec&256 ) _pad(b,width-1,' ');
         return b;
     }
-    bool signed=kind==0 || kind=='d' || kind=='i';
-    i64 base=kind=='o' ? 8 : (kind=='x' || kind=='X' ? 16 : 10);
-    u8[~] alphabet=kind=='X' ? "0123456789ABCDEF" : "0123456789abcdef";
-    val digits=new u8[22]; // Maximum: 22 octal digits for a 64-bit integer.
-    i64 count=0, n=value;
+    bool signed = kind == 0 || kind == 'd' || kind == 'i';
+    i64 base = kind == 'o' ? 8 : (kind == 'x' || kind == 'X' ? 16 : 10);
+    u8[~] alphabet = kind == 'X' ? "0123456789ABCDEF" : "0123456789abcdef";
+    val digits = new u8[22]; // Maximum: 22 octal digits for a 64-bit integer.
+    i64 count = 0, n = value;
     // Signed decimal stays nonpositive, including the minimum i64.
-    if( signed && n>0 ) n=-n;
-    if( n==0 && precision!=0 ) digits[count++]='0';
-    while( n!=0 ) {
-        i64 q=0, r=0;
-        if( signed ) { q=n/base; r=q*base-n; }
+    if( signed && n > 0 ) n = -n;
+    if( n == 0 && precision != 0 ) digits[count++] = '0';
+    while( n != 0 ) {
+        i64 q = 0, r = 0;
+        if( signed ) { q = n/base; r = q*base-n; }
         else {
             // Unsigned division without a u64 type. Halving first makes
             // the dividend nonnegative; the remainder needs at most one fix.
-            q=((n>>>1)/base)*2;
-            r=n-q*base;
-            if( r>=base ) { q++; r-=base; }
+            q = ((n>>>1)/base)*2;
+            r = n-q*base;
+            if( r >= base ) { q++; r -= base; }
         }
-        digits[count++]=alphabet[r];
-        n=q;
+        digits[count++] = alphabet[r];
+        n = q;
     }
-    u8[~] !prefix="";
+    u8[~] !prefix = "";
     if( signed ) {
-        if( value<0 ) prefix="-";
-        else if( spec&512 ) prefix="+";
-        else if( spec&1024 ) prefix=" ";
-    } else if( (spec&2048) && value!=0 ) {
-        if( kind=='x' ) prefix="0x";
-        if( kind=='X' ) prefix="0X";
+        if( value < 0 ) prefix = "-";
+        else if( spec&512 ) prefix = "+";
+        else if( spec&1024 ) prefix = " ";
+    } else if( (spec&2048) && value != 0 ) {
+        if( kind == 'x' ) prefix = "0x";
+        if( kind == 'X' ) prefix = "0X";
     }
-    i64 zeros=precision>count ? precision-count : 0;
+    i64 zeros = precision > count ? precision-count : 0;
     // Alternate octal always begins with a zero, including precision-zero 0.
-    if( kind=='o' && (spec&2048) && zeros==0 && (count==0 || digits[count-1]!='0') ) zeros=1;
-    i64 pad=width-prefix#-zeros-count;
-    bool left=(spec&256)!=0;
-    bool zero=(spec&4096)!=0 && precision<0 && !left;
+    if( kind == 'o' && (spec&2048) && zeros == 0 && (count == 0 || digits[count-1] != '0') ) zeros = 1;
+    i64 pad = width-prefix#-zeros-count;
+    bool left = (spec&256) != 0;
+    bool zero = (spec&4096) != 0 && precision < 0 && !left;
     if( !left && !zero ) _pad(b,pad,' ');
     b.addAry(prefix);
     if( zero ) _pad(b,pad,'0');
     _pad(b,zeros,'0');
-    while( count>0 ) b.add(digits[--count]);
+    while( count > 0 ) b.add(digits[--count]);
     if( left ) _pad(b,pad,' ');
     b;
 };
@@ -96,3 +93,8 @@ val f64  = { f64  x -> end(floating(begin(),x, 0 ,0,-1)); };
 val char = { i64  x -> end(integer (begin(),x,'c',0,-1)); };
 val bool = { bool x -> end(integer (begin(),x,'b',0,-1)); };
 val hex  = { i64  x -> end(integer (begin(),x,'x',0,-1)); };
+
+// Time selectors occupy spec bits 16..23; padding shares string formatting.
+val time = { !aryu8 b, i64 value, i64 spec, i64 width, i64 precision ->
+    string(b,sys.time.format(value,(spec>>>16)&255),spec,width,-1);
+};
diff --git a/src/main/smp/sys/time.smp b/src/main/smp/sys/time.smp
new file mode 100644
index 00000000..a3e9b3a2
--- /dev/null
+++ b/src/main/smp/sys/time.smp
@@ -0,0 +1,219 @@
+// Time utilities; get the current time (both nanos and millis), sleep, time zones.
+
+// Instants: bare i64 UTC Unix-epoch milliseconds. Durations: i64 milliseconds.
+// Monotonic readings are a separate clock domain, for deadlines/elapsed time.
+
+val DateTime = DateTime;
+val Timers = Timers;
+i64 SECOND = 1000;
+i64 MINUTE = 60*SECOND;
+i64 HOUR = 60*MINUTE;
+i64 DAY = 24*HOUR;
+i64 NANOS_PER_MS = 1000*1000;
+
+// Gregorian leap days: every fourth year, except centuries not divisible by 400.
+i64 _DAYS_PER_4_YEARS = 4*365+1;
+i64 _DAYS_PER_CENTURY = 100*365+100/4-1;
+i64 _DAYS_PER_ERA = 4*_DAYS_PER_CENTURY+1;
+// Complete years before the Unix epoch and after the last supported date.
+i64 _DAYS_BEFORE_EPOCH = 1969*365+1969/4-1969/100+1969/400;
+i64 _DAYS_BEFORE_YEAR_10000 = 9999*365+9999/4-9999/100+9999/400;
+// The March-based calendar algorithm starts at 0000-03-01, 306 days before 0001-01-01.
+i64 _MARCH_EPOCH_DAYS = _DAYS_BEFORE_EPOCH+306;
+i64 MIN = -_DAYS_BEFORE_EPOCH*DAY; // 0001-01-01T00:00:00.000Z
+i64 MAX = (_DAYS_BEFORE_YEAR_10000-_DAYS_BEFORE_EPOCH)*DAY-1; // 9999-12-31T23:59:59.999Z
+
+// Access to the underlying LIBC functions
+int ISO = 0, CLOCK12 = 1, CLOCK24 = 2, ELAPSED = 3, DATE = 4, CLOCK24_SECONDS = 5;
+{ i64 } simple_time_now = "C";
+{ i64 } simple_time_mono = "C";
+{ i64 } simple_time_nano = "C";
+{ i64 i32 -> i32 } simple_time_sleep = "C";
+{ i64 i64 -> i32 } simple_time_local = "C";
+{ i64 i64 u32 -> i32 } simple_time_zone = "C";
+val now       = { -> simple_time_now (); };
+val monotonic = { -> simple_time_mono(); };
+val nanoTime  = { -> simple_time_nano(); };
+val sleep      = { i64 duration_ms -> simple_time_sleep(duration_ms,0); };
+val sleepUntil = { i64 deadline_ms -> simple_time_sleep(deadline_ms,1); };
+
+// Signed duration conversions.  Overflow returns -1; reverse conversions truncate
+// toward zero.  An exact duration day is 24 hours, independent of DST.
+val _scale = { i64 n, i64 unit ->
+    if( n > sys.integer.MAX_I64/unit || n < sys.integer.MIN_I64/unit ) return -1;
+    return n*unit;
+};
+val seconds = { i64 n -> _scale(n,SECOND); };
+val minutes = { i64 n -> _scale(n,MINUTE); };
+val hours   = { i64 n -> _scale(n,HOUR); };
+val days    = { i64 n -> _scale(n,DAY); };
+val toSeconds = { i64 ms -> ms/SECOND; };
+val toMinutes = { i64 ms -> ms/MINUTE; };
+val toHours   = { i64 ms -> ms/HOUR; };
+val toDays    = { i64 ms -> ms/DAY; };
+val fromNanos = { i64 ns -> ns/NANOS_PER_MS; };
+val toNanos = { i64 ms -> _scale(ms,NANOS_PER_MS); };
+
+// Clamp to zero once due, and saturate for widely separated i64 readings.
+val remaining = { i64 deadline_ms, i64 current_ms ->
+    if( deadline_ms <= current_ms ) return 0;
+    if( current_ms < 0 && deadline_ms > sys.integer.MAX_I64+current_ms ) return sys.integer.MAX_I64;
+    return deadline_ms-current_ms;
+};
+
+val _mod = { i64 n, i64 unit -> n-n/unit*unit; };
+val leap = { int year -> _mod(year,4) == 0 && (_mod(year,100) != 0 || _mod(year,400) == 0); };
+val monthDays = { int year, int month ->
+    if( month < 1 || month > 12 ) return 0;
+    return month == 2 ? (leap(year) ? 29 : 28) :
+        month == 4 || month == 6 || month == 9 || month == 11 ? 30 : 31;
+};
+
+// Gregorian civil dates, expressed using 400-year eras; no per-year loops.
+val _days = { i64 year, i64 month, i64 day ->
+    year -= month <= 2 ? 1 : 0;
+    i64 era = year/400, y = year-era*400;
+    i64 mp = month+(month > 2 ? -3 : 9);
+    return era*_DAYS_PER_ERA+y*365+y/4-y/100+(153*mp+2)/5+day-1-_MARCH_EPOCH_DAYS;
+};
+
+val valid = { int year, int month, int day, int hour, int minute, int second, int millisecond ->
+    return year >= 1 && year <= 9999 && month >= 1 && month <= 12 && day >= 1 && day <= monthDays(year,month) &&
+        hour >= 0 && hour <= 23 && minute >= 0 && minute <= 59 && second >= 0 && second <= 59 &&
+        millisecond >= 0 && millisecond <= 999;
+};
+
+val makeUTC = { int year, int month, int day, int hour, int minute, int second, int millisecond ->
+    if( !valid(year,month,day,hour,minute,second,millisecond) ) return -1;
+    return _days(year,month,day)*DAY+hour*HOUR+minute*MINUTE+second*SECOND+millisecond;
+};
+
+val utc = { i64 instant ->
+    val d = DateTime.empty();
+    if( instant < MIN || instant > MAX ) return d;
+    i64 day = instant/DAY, rest = _mod(instant,DAY);
+    if( rest < 0 ) { rest += DAY; day--; }
+    i64 z = day+_MARCH_EPOCH_DAYS, era = z/_DAYS_PER_ERA, doe = z-era*_DAYS_PER_ERA;
+    i64 y = (doe-doe/(_DAYS_PER_4_YEARS-1)+doe/_DAYS_PER_CENTURY-doe/(_DAYS_PER_ERA-1))/365;
+    i64 doy = doe-(365*y+y/4-y/100), mp = (5*doy+2)/153;
+    d.day = doy-(153*mp+2)/5+1;
+    d.month = mp+(mp < 10 ? 3 : -9);
+    d.year = y+era*400+(d.month <= 2 ? 1 : 0);
+    d.hour = rest/HOUR; d.minute = _mod(rest/MINUTE,60);
+    d.second = _mod(rest/SECOND,60); d.millisecond = _mod(rest,SECOND);
+    d.weekday = _mod(day+4,7);
+    if( d.weekday < 0 ) d.weekday += 7;
+    return d;
+};
+
+val local = { i64 instant ->
+    val d = DateTime.empty();
+    val f = new i64[10];
+    i64 ptr = f;
+    if( simple_time_local(instant,ptr) != 0 ) return d;
+    d.year = f[0]; d.month = f[1]; d.day = f[2];
+    d.hour = f[3]; d.minute = f[4]; d.second = f[5]; d.millisecond = f[6];
+    d.weekday = f[7]; d.offsetSeconds = f[8]; d.daylight = f[9] != 0;
+    return d;
+};
+
+val zoneName = { i64 instant ->
+    val bytes = new u8[128];
+    i64 ptr = bytes;
+    int n = simple_time_zone(instant,ptr,bytes#);
+    if( n < 0 ) return "";
+    val b = new aryu8();
+    for( int i = 0; i < n; i++ ) b.add(bytes[i]);
+    return text.end(b);
+};
+
+val _digits = { !aryu8 b, i64 n, int width ->
+    text.integer(b,n,'d'|4096,width,-1);
+};
+
+val _format = { i64 instant, int style, bool localZone ->
+    val d = localZone ? local(instant) : utc(instant);
+    if( d.year == 0 || style < 0 || style > 5 || style == 3 ) return "<invalid time>";
+    val b = new aryu8();
+    if( style == 4 ) {
+        _digits(b,d.day,2).add('/'); _digits(b,d.month,2).add('/'); _digits(b,_mod(d.year,100),2);
+    } else {
+        if( style == 0 ) {
+            _digits(b,d.year,4).add('-'); _digits(b,d.month,2).add('-'); _digits(b,d.day,2).add('T');
+        }
+        int hour = d.hour;
+        if( style == 1 ) { hour = _mod(hour,12); if( hour == 0 ) hour = 12; }
+        _digits(b,hour,style == 1 ? 1 : 2).add(':'); _digits(b,d.minute,2);
+        if( style == 0 || style == 5 ) { b.add(':'); _digits(b,d.second,2); }
+        if( style == 1 ) b.addAry(d.hour < 12 ? "am" : "pm");
+        if( style == 0 ) {
+            b.add('.'); _digits(b,d.millisecond,3);
+            if( d.offsetSeconds == 0 ) b.add('Z');
+            else {
+                i64 offset = d.offsetSeconds;
+                b.add(offset < 0 ? '-' : '+');
+                if( offset < 0 ) offset = -offset;
+                _digits(b,offset/3600,2).add(':'); _digits(b,_mod(offset/60,60),2);
+                if( _mod(offset,60) != 0 ) { b.add(':'); _digits(b,_mod(offset,60),2); }
+            }
+        }
+    }
+    return text.end(b);
+};
+
+val elapsed = { i64 ms ->
+    val b = new aryu8();
+    // Nonpositive arithmetic handles the minimum i64 without negating it.
+    if( ms < 0 ) b.add('-'); else ms = -ms;
+    _digits(b,-(ms/MINUTE),2).add(':');
+    _digits(b,-_mod(ms/SECOND,60),2).add('.'); _digits(b,-_mod(ms,SECOND),3);
+    return text.end(b);
+};
+val format = { i64 instant, int style ->
+    if( style == ELAPSED ) return elapsed(instant);
+    return _format(instant,style,false);
+};
+val formatLocal = { i64 instant, int style ->
+    if( style == ELAPSED ) return elapsed(instant);
+    return _format(instant,style,true);
+};
+
+val _number = { u8[~] s, i64 at, int count ->
+    if( at < 0 || count < 1 || at+count > s# ) return -1;
+    int n = 0;
+    for( int i = 0; i < count; i++ ) {
+        int c = s[at+i];
+        if( c < '0' || c > '9' ) return -1;
+        n = n*10+c-'0';
+    }
+    return n;
+};
+
+// Keep suffix validation separate from calendar construction.
+val _parseZone = { u8[~] s, int at, i64 instant ->
+    if( at < 0 || at >= s# ) return -1;
+    i64 offset = 0;
+    if( s[at] == 'Z' ) { if( at+1 != s# ) return -1; }
+    else {
+        int sign = s[at] == '+' ? 1 : s[at] == '-' ? -1 : 0;
+        if( !sign || (s# != at+6 && s# != at+9) || s[at+3] != ':' ) return -1;
+        int oh = _number(s,at+1,2), om = _number(s,at+4,2), os = 0;
+        if( s# == at+9 ) { if( s[at+6] != ':' ) return -1; os = _number(s,at+7,2); }
+        if( oh < 0 || oh > 23 || om < 0 || om > 59 || os < 0 || os > 59 ) return -1;
+        offset = sign*(oh*HOUR+om*MINUTE+os*SECOND);
+    }
+    instant -= offset;
+    return instant < MIN || instant > MAX ? -1 : instant;
+};
+
+// Strict ISO absolute instants only. -1 is reserved for failure (and therefore
+// cannot distinguish the valid instant one millisecond before Unix epoch).
+val parse = { u8[~] s ->
+    if( s# < 20 || s[4] != '-' || s[7] != '-' || s[10] != 'T' || s[13] != ':' || s[16] != ':' ) return -1;
+    int y = _number(s, 0,4), m   = _number(s, 5,2), d   = _number(s, 8,2);
+    int h = _number(s,11,2), min = _number(s,14,2), sec = _number(s,17,2);
+    bool fraction = s[19] == '.';
+    int ms = fraction ? _number(s,20,3) : 0;
+    if( !valid(y,m,d,h,min,sec,ms) ) return -1;
+    return _parseZone(s,fraction ? 23 : 19,makeUTC(y,m,d,h,min,sec,ms));
+};
diff --git a/src/main/smp/sys/time/DateTime.smp b/src/main/smp/sys/time/DateTime.smp
new file mode 100644
index 00000000..53b6688e
--- /dev/null
+++ b/src/main/smp/sys/time/DateTime.smp
@@ -0,0 +1,13 @@
+// Calendar view of an instant. Month/day start at 1; weekday is Sunday=0.
+// year==0 means out of the supported calendar range (years 1 through 9999).
+
+// All values default zero/false
+struct DateTime {
+    int year, month, day;
+    int hour, minute, second, millisecond;
+    int weekday, offsetSeconds;
+    bool daylight;
+};
+
+// Factory in the defining unit, so callers need no forward instance type.
+val empty = { -> new DateTime(); };
diff --git a/src/main/smp/sys/time/Timers.smp b/src/main/smp/sys/time/Timers.smp
new file mode 100644
index 00000000..7cca2e9c
--- /dev/null
+++ b/src/main/smp/sys/time/Timers.smp
@@ -0,0 +1,80 @@
+// Cooperative timers. poll returns IDs; callbacks never run on another thread.
+// IDs are u32; 0 means failure or no timer due. Millisecond values use _ms.
+
+// The
+
+
+struct Timers {
+    // Collection of timers (as struct-of-arrays)
+    u32[] !_ids       = new u32[8]; // Which timer id for this slot
+    i64[] !_due_ms    = new i64[8]; // Monotonic deadline in milliseconds
+    i64[] !_period_ms = new i64[8]; // When does it repeat
+    // Next available timer ID; 0 means all IDs have been used.
+    u32 !_next = 1;
+
+    // Add a new timer
+    { i64 i64 i64 -> u32 } _add = { i64 current_ms, i64 delay_ms, i64 period_ms ->
+        if( current_ms < 0 || delay_ms < 0 || current_ms > sys.integer.MAX_I64-delay_ms || _next == 0 ) return 0;
+        // Ugly linear scan for an available slot
+        int slot = 0;
+        while( slot < _ids# && _ids[slot] != 0 ) slot++;
+        // Double size for lots of timers
+        if( slot == _ids# ) {
+            if( _ids# > sys.integer.MAX_I32/2 ) return 0;
+            val ids = new u32[_ids#*2];
+            val due_ms = new i64[_ids#*2], periods_ms = new i64[_ids#*2];
+            for( int i = 0; i < _ids#; i++ ) { ids[i] = _ids[i]; due_ms[i] = _due_ms[i]; periods_ms[i] = _period_ms[i]; }
+            _ids = ids; _due_ms = due_ms; _period_ms = periods_ms;
+            // Retry against the newly published arrays after growing.
+            return _add(current_ms,delay_ms,period_ms);
+        }
+        // Next available timer id
+        u32 id = _next;
+        _next = id == sys.integer.MAX_U32 ? 0 : id+1;
+        _ids[slot] = id; _due_ms[slot] = current_ms+delay_ms; _period_ms[slot] = period_ms;
+        return id;
+    };
+
+    // Explicit-clock versions make game logic and tests deterministic.
+    { i64 i64 -> u32 } afterAt = { i64 current_ms, i64 delay_ms -> _add(current_ms,delay_ms,0); };
+    { i64 i64 -> u32 } everyAt = { i64 current_ms, i64 period_ms -> period_ms <= 0 ? 0 : _add(current_ms,period_ms,period_ms); };
+    { i64 -> u32 } after = { i64 delay_ms  -> afterAt(time.monotonic(),delay_ms ); };
+    { i64 -> u32 } every = { i64 period_ms -> everyAt(time.monotonic(),period_ms); };
+
+    // Remove a timer
+    val cancel = { u32 id ->
+        if( id == 0 ) return false;
+        for( int i = 0; i < _ids#; i++ ) if( _ids[i] == id ) { _ids[i] = 0; return true; }
+        return false;
+    };
+
+    // Earliest absolute monotonic deadline in milliseconds, or -1 when empty.
+    val nextDeadline = { ->
+        i64 next_ms = -1;
+        // Ugly linear scan again, but short
+        for( int i = 0; i < _ids#; i++ )
+            if( _ids[i] != 0 && (next_ms < 0 || _due_ms[i] < next_ms) ) next_ms = _due_ms[i];
+        return next_ms;
+    };
+
+    // Next firing timer.
+
+    // Earliest deadline first; equal deadlines use registration order.
+    // Repeats skip missed ticks and retain their phase, avoiding bursts/drift.
+    { i64 -> u32 } poll = { i64 current_ms ->
+        int slot = -1;
+        for( int i = 0; i < _ids#; i++ )
+            if( _ids[i] != 0 && _due_ms[i] <= current_ms && (slot < 0 || _due_ms[i] < _due_ms[slot] ||
+                (_due_ms[i] == _due_ms[slot] && _ids[i] < _ids[slot])) ) slot = i;
+        if( slot < 0 ) return 0;
+        u32 id = _ids[slot];
+        i64 period_ms = _period_ms[slot];
+        if( period_ms == 0 ) _ids[slot] = 0;
+        else {
+            i64 steps = (current_ms-_due_ms[slot])/period_ms;
+            if( steps >= (sys.integer.MAX_I64-_due_ms[slot])/period_ms ) _ids[slot] = 0;
+            else _due_ms[slot] += (steps+1)*period_ms;
+        }
+        return id;
+    };
+};