Support post ++ on arrays and structs

2 files changed, 41 insertions, 6 deletions

diff --git a/chapter17/src/test/java/com/seaofnodes/simple/BrainFuckTest.java b/chapter17/src/test/java/com/seaofnodes/simple/BrainFuckTest.java
index 0a48d2e7..88dccc49 100644
--- a/chapter17/src/test/java/com/seaofnodes/simple/BrainFuckTest.java
+++ b/chapter17/src/test/java/com/seaofnodes/simple/BrainFuckTest.java
@@ -23,10 +23,8 @@ public class BrainFuckTest {
 
         Parser parser = new Parser(
                 encoded + """
-int pc = 0;
-int d = 0;
-u8[] data = new u8[100];
-u8[] output = new u8[0];
+int pc = 0, d = 0;
+u8[] data = new u8[100],  output = new u8[0];
 
 while (pc < program#) {
     int command = program[pc];
@@ -35,9 +33,9 @@ while (pc < program#) {
     } else if (command == 60) {
         d--;
     } else if (command == 43) {
-        data[d] = data[d] + 1;
+        data[d]++;
     } else if (command == 45) {
-        data[d] = data[d] - 1;
+        data[d]--;
     } else if (command == 46) {
         u8[] old = output;
         output = new u8[output# + 1];
diff --git a/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java b/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
index 91c275ce..45e3ef0f 100644
--- a/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
+++ b/chapter17/src/test/java/com/seaofnodes/simple/Chapter17Test.java
@@ -49,6 +49,43 @@ return -arg---arg--;
         assertEquals(1L, Evaluator.evaluate(stop, 0));
     }
 
+    @Test
+    public void testInc3() {
+        Parser parser = new Parser("""
+int[] xs = new int[arg];
+xs[0]++;
+xs[1]++;
+return xs[0];
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 1;", stop.toString());
+        assertEquals(1L, Evaluator.evaluate(stop, 2));
+    }
+
+    @Test
+    public void testInc4() {
+        Parser parser = new Parser("""
+u8[] xs = new u8[1];
+xs[0]--;
+return xs[0];
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 255;", stop.toString());
+        assertEquals(255L, Evaluator.evaluate(stop, 2));
+    }
+
+    @Test
+    public void testInc5() {
+        Parser parser = new Parser("""
+struct S { u16 x; };
+S s = new S;
+s.x--;
+return s.x;
+""");
+        StopNode stop = parser.parse().iterate();
+        assertEquals("return 65535;", stop.toString());
+        assertEquals(65535L, Evaluator.evaluate(stop, 2));
+    }
 
     @Test
     public void testLinkedList2() {