Finish simple pretty printer in gst.

Discovered memory leaks. Seems to have to do with improper marking of
the stack and or the VM messes up the stack.

core/ds.c

@@ -276,21 +276,20 @@ void gst_object_put(Gst *vm, GstObject *o, GstValue key, GstValue value) {
 
 /* Find next key in an object. Returns nil if no next key. */
 GstValue gst_object_next(GstObject *o, GstValue key) {
-    GstValue ret;
-    GstValue *bucket;
-    if (key.type == GST_NIL)
-       bucket = o->data - 2;
-    else
-       bucket = gst_object_find(o, key); 
-    if (bucket && bucket[0].type != GST_NIL) {
-        GstValue *nextbucket, *end;
+    const GstValue *bucket, *end;
     end = o->data + o->capacity; 
-        for (nextbucket = bucket + 2; nextbucket < end; nextbucket += 2) {
-            if (nextbucket[0].type != GST_NIL)
-                return nextbucket[0];
+    if (key.type == GST_NIL) {
+        bucket = o->data;
+    } else {
+        bucket = gst_object_find(o, key); 
+        if (!bucket || bucket[0].type == GST_NIL)
+            return gst_wrap_nil();
+        bucket += 2;
     }
+    for (; bucket < end; bucket += 2) {
+        if (bucket[0].type != GST_NIL)
+            return bucket[0];
     }
-    ret.type = GST_NIL;
-    return ret;
+    return gst_wrap_nil();
 }
 

core/ids.c

@@ -288,23 +288,21 @@ GstValue gst_struct_get(const GstValue *st, GstValue key) {
 
 /* Get the next key in a struct */
 GstValue gst_struct_next(const GstValue *st, GstValue key) {
-    GstValue ret;
-    const GstValue *bucket;
-    if (key.type == GST_NIL)
-        bucket = st - 2;
-    else
-        bucket = gst_struct_find(st, key); 
-    if (bucket && bucket[0].type != GST_NIL) {
-        const GstValue *nextbucket, *end;
+    const GstValue *bucket, *end;
     end = st + gst_struct_capacity(st);
-        for (nextbucket = bucket + 2; nextbucket < end; nextbucket += 2) {
-            if (nextbucket[0].type != GST_NIL)
-                return nextbucket[0];
+    if (key.type == GST_NIL) {
+        bucket = st;
+    } else {
+        bucket = gst_struct_find(st, key); 
+        if (!bucket || bucket[0].type == GST_NIL)
+            return gst_wrap_nil();
+        bucket += 2;
     }
+    for (; bucket < end; bucket += 2) {
+        if (bucket[0].type != GST_NIL)
+            return bucket[0];
     }
-    ret.type = GST_NIL;
-    return ret;
-
+    return gst_wrap_nil();
 }
 
 /****/

core/stl.c

@@ -104,6 +104,11 @@ COMPARE_FUNCTION(greaterthaneq, gst_compare(lhs, rhs) >= 0)
 
 #undef COMPARE_FUNCTION
 
+/* Boolean not */
+int gst_stl_not(Gst *vm) {
+    gst_c_return(vm, gst_wrap_boolean(!gst_truthy(gst_arg(vm, 0))));
+}
+
 /****/
 /* Core */
 /****/
@@ -533,7 +538,7 @@ int gst_stl_open(Gst *vm) {
 /* Temporary */
 /****/
 
-/* These functions should definitely be moved to a different module, remove, or
+/* These functions should definitely be moved to a different module, removed, or
  * rewritten in gst when the language is complete enough. This is not to say
  * that functions in other section need not be moved. */
 
@@ -564,6 +569,7 @@ static const GstModuleItem const std_module[] = {
     {"=", gst_stl_equal},
     {"<=", gst_stl_lessthaneq},
     {">=", gst_stl_greaterthaneq},
+    {"not", gst_stl_not},
     {"length", gst_stl_length},
     {"to-integer", gst_stl_to_int},
     {"to-real", gst_stl_to_real},

core/vm.c

@@ -38,7 +38,7 @@ int gst_continue(Gst *vm) {
 #define gst_assert(vm, cond, e) do {if (!(cond)){gst_error((vm), (e));}} while (0)
 
     /* Intialize local state */
-    stack = vm->thread->data + vm->thread->count;
+    stack = gst_thread_stack(vm->thread);
     pc = gst_frame_pc(stack);
 
     /* Main interpreter loop */
@@ -291,7 +291,6 @@ int gst_continue(Gst *vm) {
             gst_frame_env(stack) = NULL;
             gst_thread_endframe(vm, vm->thread);
             stack = vm->thread->data + vm->thread->count;
-            gst_frame_args(stack) = 0;
             temp = gst_frame_callee(stack);
             if (temp.type == GST_FUNCTION) {
                 pc = temp.data.function->def->byteCode;

libs/pp.gst

@@ -1,30 +1,59 @@
 # Pretty print
 
-# Reindent a function to be more deeply indented
-(: reindent (fn [x] x))
+# Declare pretty print
+(: pp nil)
 
-# Pretty print an array
-(: print-array (fn [a]
+# Pretty print an array or tuple
+(: print-seq (fn [start end a]
     (: parts [])
-    (: l (length a))
+    (: len (length a))
     (: i 0)
-    (while (< i l)
-         
+    (while (< i len)
+        (push parts (pp (rawget a i)))
+        (push parts " ")
         (: i (+ 1 i)))
-    (apply strcat "[ " parts)))
+    (if (> len 0) (pop parts))
+    (push parts end)
+    (apply strcat start parts)))
 
-(: handler {
-    "number" tostring
+# Pretty print an object or struct
+(: print-struct (fn [start end s]
+    (: parts [])
+    (: key (next s))
+    (while (not (= key nil))
+        (push parts (pp key))
+        (push parts " ")
+        (push parts (pp (rawget s key)))
+        (push parts " ")
+        (: key (next s key)))
+    (if (> (length parts) 0) (pop parts))
+    (push parts end)
+    (apply strcat start parts)))
+
+# Pretty 
+
+(: handlers {
+    "real" tostring
+    "integer" tostring
     "nil" tostring
     "boolean" tostring
     "userdata" tostring
     "cfunction" tostring
     "function" tostring
-    "string" tostring # change to unquote string
+    "string" tostring
     "buffer" tostring
-    "array" tostring
-    "tuple" tostring
-    "object" tostring
-    "struct" tostring
+    "array" (fn [a] (print-seq "[" "]" a))
+    "tuple" (fn [a] (print-seq "(" ")" a))
+    "object" (fn [s] (print-struct "{" "}" s))
+    "struct" (fn [s] (print-struct "#{" "}" s))
     "thread" tostring 
  })
+
+# Define pretty print
+(: pp (fn [x]
+    (: h (rawget handlers (type x)))
+    (h x)))
+
+(print (pp [1 {4 5 6 7} 2 3]))
+
+(print "DONE!")