fix repeat stack discipline

may_2025_thoughts.md

@@ -494,5 +494,8 @@ Here's a list of things that need doing:
     - I need this fixed for optimization reasons.
     - I _think_ I just fixed this by fixing tail position tracking in collections
     - [ ] test this
-* [ ] Dict patterns are giving me stack discipline grief. Why is stack discipline so hard?
+* [x] Dict patterns are giving me stack discipline grief. Why is stack discipline so hard?
+* [ ] This is in the service of getting turtle graphics working
+* Other forms in the language need help:
+    * [ ] repeat needs its stack discipline updated, it currently crashes the compiler
 

sandbox.ld

@@ -35,6 +35,11 @@
 & 	& (:background, _) -> state
 & }
 
-let foo = #{:a 1, :b 2, :c 3}
-let #{a, b, ...c} = foo
+box foos = []
+
+repeat 4 {
+	update! (foos, append (_, :foo))
+}
+
+do foos > unbox > count
 

src/compiler.rs

@@ -724,6 +724,7 @@ impl<'a> Compiler<'a> {
                         };
                         self.emit_constant(Value::Keyword(key));
                         self.emit_op(Op::DropDictEntry);
+                        self.stack_depth -= 1;
                     }
 
                     if let Some(splatt) = splattern {
@@ -1241,7 +1242,7 @@ impl<'a> Compiler<'a> {
                 // begin repeat
                 self.emit_op(Op::Decrement);
                 let repeat_begin = self.len();
-                self.emit_op(Op::Duplicate);
+                self.duplicate();
                 let jiz_idx = self.stub_jump(Op::JumpIfZero);
                 // compile the body
                 self.visit(body);

src/vm.rs

@@ -910,7 +910,7 @@ impl Vm {
                             for i in 0..arity as usize {
                                 self.return_register[arity as usize - i - 1] = self.pop();
                             }
-                            self.print_stack();
+                            // self.print_stack();
 
                             // then pop everything back to the current stack frame
                             self.stack.truncate(self.frame.stack_base);
@@ -976,10 +976,10 @@ impl Vm {
                             // self.ip = self.frame.ip;
                             // // finally, throw the value on the stack
                             self.push(value);
-                            println!(
-                                "=== returning to {} ===",
-                                self.frame.function.as_fn().name()
-                            );
+                            // println!(
+                            //     "=== returning to {} ===",
+                            //     self.frame.function.as_fn().name()
+                            // );
                         }
                         Value::Partial(partial) => {
                             let last_arg = self.pop();