From eee5b806fabae0b480ff7d41159369c5a457d014 Mon Sep 17 00:00:00 2001
From: Cliff Click <cliffc@acm.org>
Date: Tue, 26 Nov 2024 11:01:47 -0800
Subject: Chapter 18: Functions

---
 src/main/java/com/seaofnodes/simple/Var.java | 55 ++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 src/main/java/com/seaofnodes/simple/Var.java

(limited to 'src/main/java/com/seaofnodes/simple/Var.java')

diff --git a/src/main/java/com/seaofnodes/simple/Var.java b/src/main/java/com/seaofnodes/simple/Var.java
new file mode 100644
index 00000000..e71d7ef2
--- /dev/null
+++ b/src/main/java/com/seaofnodes/simple/Var.java
@@ -0,0 +1,55 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.type.*;
+
+
+/**
+ *  The tracked fields are now complex enough to deserve a array-of-structs layout
+ */
+public class Var {
+
+    public final String _name;   // Declared name
+    public int _idx;             // index in containing scope
+    private Type _type;          // Declared type
+    public boolean _final;       // Final field
+    public Parser.Lexer _loc;    // Source location
+    public boolean _fref;        // Forward ref
+
+    public Var(int idx, String name, Type type, boolean xfinal, Parser.Lexer loc ) {
+        this(idx,name,type,xfinal,loc,false);
+    }
+    public Var(int idx, String name, Type type, boolean xfinal, Parser.Lexer loc, boolean fref) {
+        _idx = idx;
+        _name = name;
+        _type = type;
+        _final = xfinal;
+        _loc = loc;
+        _fref = fref;
+    }
+    public Type type() {
+        if( !_type.isFRef() ) return _type;
+        // Update self to no longer use the forward ref type
+        Type def = Parser.TYPES.get(((TypeMemPtr)_type)._obj._name);
+        return (_type=_type.meet(def));
+    }
+    public Type lazyGLB() {
+        Type t = type();
+        return t instanceof TypeMemPtr ? t : t.glb();
+    }
+
+    // Forward reference variables (not types) must be BOTTOM and
+    // distinct from inferred variables
+    public boolean isFRef() { return _fref; }
+
+    public void defFRef( Type type, boolean xfinal, Parser.Lexer loc ) {
+        assert isFRef() && xfinal;
+        _type = type;
+        _final = true;
+        _loc = loc;
+        _fref = false;
+    }
+
+    @Override public String toString() {
+        return _type.toString()+(_final ? " ": " !")+_name;
+    }
+}
-- 
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