Making some changes.

Makefile

@@ -15,6 +15,10 @@ GST_CORELIB=core/libgst.a
 GST_INTERNAL_HEADERS=$(addprefix core/, cache.h)
 GST_HEADERS=$(addprefix include/gst/, gst.h)
 
+# Use gdb. On mac use lldb
+DEBUGGER=lldb
+CC=clang
+
 all: $(GST_TARGET)
 
 ###################################
@@ -42,7 +46,7 @@ run: $(GST_TARGET)
 	@ ./$(GST_TARGET)
 
 debug: $(GST_TARGET)
-	@ gdb ./$(GST_TARGET)
+	@ $(DEBUGGER) ./$(GST_TARGET)
 
 valgrind: $(GST_TARGET)
 	@ valgrind --leak-check=full -v ./$(GST_TARGET)

core/ds.c

@@ -278,6 +278,16 @@ void gst_table_put(Gst *vm, GstTable *t, GstValue key, GstValue value) {
     }
 }
 
+/* Clear a table */
+void gst_table_clear(GstTable *t) {
+    uint32_t capacity = t->capacity;
+    uint32_t i;
+    GstValue *data = t->data;
+    for (i = 0; i < capacity; i += 2)
+        data[i].type = GST_NIL;
+    t->count = 0;
+}
+
 /* Find next key in an object. Returns nil if no next key. */
 GstValue gst_table_next(GstTable *t, GstValue key) {
     const GstValue *bucket, *end;

core/stl.c

@@ -168,6 +168,25 @@ int gst_stl_not(Gst *vm) {
 /* Core */
 /****/
 
+/* Empty a mutable datastructure */
+int gst_stl_clear(Gst *vm) {
+    GstValue x = gst_arg(vm, 0);
+    switch (x.type) {
+    default:
+        gst_c_throwc(vm, "cannot get length");
+    case GST_ARRAY:
+        x.data.array->count = 0;
+        break;
+    case GST_BYTEBUFFER:
+        x.data.buffer->count = 0;
+        break;
+    case GST_TABLE:
+        gst_table_clear(x.data.table);
+        break;
+    }
+    gst_c_return(vm, x);
+}
+
 /* Get length of object */
 int gst_stl_length(Gst *vm) {
     uint32_t count = gst_count_args(vm);
@@ -1037,12 +1056,12 @@ static const GstModuleItem std_module[] = {
     {"parse-hasvalue", gst_stl_parser_hasvalue},
     {"parse-charseq", gst_stl_parser_charseq},
     {"parse-status", gst_stl_parser_status},
-    {"parse-status", gst_stl_parser_status},
     {"parse", gst_stl_parse},
     /* Compile */
     {"compile", gst_stl_compile},
     /* Other */
     {"not", gst_stl_not},
+    {"clear", gst_stl_clear},
     {"length", gst_stl_length},
     {"hash", gst_stl_hash},
     {"integer", gst_stl_to_int},

core/thread.c

@@ -138,15 +138,14 @@ void gst_thread_endframe(Gst *vm, GstThread *thread) {
     GstValue callee = gst_frame_callee(stack);
     if (callee.type == GST_FUNCTION) {
         GstFunction *fn = callee.data.function;
+        uint32_t locals = fn->def->locals;
         gst_frame_pc(stack) = fn->def->byteCode;
         if (fn->def->flags & GST_FUNCDEF_FLAG_VARARG) {
             uint32_t arity = fn->def->arity;
             gst_thread_tuplepack(vm, thread, arity);
-        } else {
+        }
-            uint32_t locals = fn->def->locals;
+        if (gst_frame_size(stack) < locals) {
-            if (gst_frame_size(stack) < locals) {
+            gst_thread_pushnil(vm, thread, locals - gst_frame_size(stack));
-                gst_thread_pushnil(vm, thread, locals - gst_frame_size(stack));
-            }
         }
     }
 }

include/gst/gst.h

@@ -472,6 +472,7 @@ GstTable *gst_table(Gst *vm, uint32_t capacity);
 GstValue gst_table_get(GstTable *t, GstValue key);
 GstValue gst_table_remove(GstTable *t, GstValue key);
 void gst_table_put(Gst *vm, GstTable *t, GstValue key, GstValue value);
+void gst_table_clear(GstTable *t);
 GstValue gst_table_next(GstTable *o, GstValue key);
 
 /****/

libs/repl.gst

@@ -0,0 +1,26 @@
+(var *sourcefile* stdin)
+
+(var *compile* (fn [x]
+	(def ret (compile x))
+	(if (= :function (type ret))
+		ret
+		(error (string "compile error: " ret)))))
+
+(var *read* (fn []
+	(def b (buffer))
+	(def p (parser))
+	(while (not (parse-hasvalue p))
+		(read *sourcefile* 1 b)
+		(if (= (length b) 0)
+			(error "unexpected end of source"))
+		(parse-charseq p b)
+		(clear b))
+	(parse-consume p)))
+
+(def eval (fn [x]
+	(apply (*compile* x) 123)))
+
+(def t (thread (fn []
+	(while true
+		(eval (*read*))))))
+(print (tran t))