Simplify variable lookup and implicit variable declarations.

minproto.leg

@@ -1,6 +1,6 @@
 # minproto.leg -- minimal prototype langauge for semantic experiments
 #
-# last edited: 2024-05-29 11:05:04 by piumarta on zora
+# last edited: 2024-05-29 14:20:52 by piumarta on zora
 
 %{
 ;
@@ -784,24 +784,21 @@ oop Object_get(oop obj, oop key)
 
 oop *_refvar(oop obj, oop key)
 {
-    while (is(Object, obj)) {
+    while (is(Object, obj)) { // look for a binding of key in the local scopes
         ssize_t ind = Object_find(obj, key);
         if (ind >= 0) return &_get(obj, Object,properties)[ind].val;
         obj = _getDelegate(obj);
     }
     int numspaces  = _get(namespaces, Object,isize);
-    if (numspaces) {
+    if (numspaces) { // look for a binding of key in the namespace stack
         oop *nss = _get(namespaces, Object,indexed);
         for (int i = numspaces;  i--;) {
             oop ns = nss[i];
-            while (is(Object, ns)) {
-                ssize_t ind = Object_find(ns, key);
-                if (ind >= 0) return &_get(ns, Object,properties)[ind].val;
-                ns = _getDelegate(ns);
-            }
+            ssize_t ind = Object_find(ns, key);
+            if (ind >= 0) return &_get(ns, Object,properties)[ind].val;
         }
     }
-    oop *ref = &_get(key, Symbol,value); // asserts is(Symbol,key)
+    oop *ref = &_get(key, Symbol,value); // use the global binding
     return ref;
 }
 
@@ -822,18 +819,14 @@ oop Object_put(oop obj, oop key, oop val);
 oop setvar(oop obj, oop key, oop val)
 {
     oop env = obj;
-    while (is(Object, env)) {
+    while (is(Object, env)) { // look for a binding of key in the local scopes
         ssize_t ind = Object_find(env, key);
-        if (ind >= 0) return _get(env, Object,properties)[ind].val = val;
+        if (ind >= 0) return _get(env, Object,properties)[ind].val = val; // set it
         env = _getDelegate(env);
     }
-    int numspaces  = _get(namespaces, Object,isize);
-    if (numspaces) {
-        oop *nss = _get(namespaces, Object,indexed);
-        return Object_put(nss[numspaces - 1], key, val);
-    }
-    if (nil != obj) return Object_put(obj, key, val);
-    return _get(key, Symbol,value) = val; // asserts is(Symbol,key)
+    return (nil == obj)                 // are we at the top level?
+        ? _get(key, Symbol,value) = val // set a global variable
+        : Object_put(obj, key, val);    // create a new local variable
 }
 
 oop Object_put(oop obj, oop key, oop val)