Prefix 'local' constrins variables to be in current scope. Variable references, inrement operator l-values, and function definitions can all be qualified 'local' or 'global'.

minproto.leg

@@ -1,6 +1,6 @@
 # minproto.leg -- minimal prototype langauge for semantic experiments
 #
-# last edited: 2024-05-29 14:20:52 by piumarta on zora
+# last edited: 2024-05-30 14:46:11 by piumarta on zora
 
 %{
 ;
@@ -108,9 +108,9 @@ oop printOn(oop buf, oop obj, int indent);
 #endif
 
 #if PRIMCLOSURE
-#define doProtos(_) _(Object) _(RefSym) _(GetSym) _(SetSym) _(RefVar) _(GetVar) _(SetVar) _(RefProp) _(GetProp) _(SetProp) _(RefArray) _(GetArray) _(SetArray) _(Call) _(Invoke) _(Continue) _(Break) _(Return) _(TryCatch) _(TryEnsure)_(Raise)_(Binop) _(Unyop) _(If) _(While) _(Block) _(For) _(ForIn) _(ForFromTo) _(Literal)
+#define doProtos(_) _(Object) _(RefLocal) _(GetLocal) _(SetLocal) _(RefGlobal) _(GetGlobal) _(SetGlobal) _(RefVar) _(GetVar) _(SetVar) _(RefProp) _(GetProp) _(SetProp) _(RefArray) _(GetArray) _(SetArray) _(Call) _(Invoke) _(Continue) _(Break) _(Return) _(TryCatch) _(TryEnsure)_(Raise)_(Binop) _(Unyop) _(If) _(While) _(Block) _(For) _(ForIn) _(ForFromTo) _(Literal)
 #else
-#define doProtos(_) _(Object) _(RefSym) _(GetSym) _(SetSym) _(RefVar) _(GetVar) _(SetVar) _(RefProp) _(GetProp) _(SetProp) _(RefArray) _(GetArray) _(SetArray) _(Call) _(Invoke) _(Continue) _(Break) _(Return) _(TryCatch) _(TryEnsure) _(Raise) _(Binop) _(Unyop) _(If) _(While) _(Block) _(For) _(ForIn) _(ForFromTo) _(Literal) _(Lambda) _(Closure)
+#define doProtos(_) _(Object) _(RefLocal) _(GetLocal) _(SetLocal) _(RefGlobal) _(GetGlobal) _(SetGlobal) _(RefVar) _(GetVar) _(SetVar) _(RefProp) _(GetProp) _(SetProp) _(RefArray) _(GetArray) _(SetArray) _(Call) _(Invoke) _(Continue) _(Break) _(Return) _(TryCatch) _(TryEnsure) _(Raise) _(Binop) _(Unyop) _(If) _(While) _(Block) _(For) _(ForIn) _(ForFromTo) _(Literal) _(Lambda) _(Closure)
 #endif
 
 #define  declareProto(NAME)     oop p##NAME = 0;
@@ -824,9 +824,14 @@ oop setvar(oop obj, oop key, oop val)
         if (ind >= 0) return _get(env, Object,properties)[ind].val = val; // set it
         env = _getDelegate(env);
     }
-    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
+    if (nil != obj) return Object_put(obj, key, val); // create a new local variable
+    int numspaces  = _get(namespaces, Object,isize);
+    if (numspaces) {
+        oop *nss = _get(namespaces, Object,indexed);
+        oop  ns  = nss[numspaces - 1];
+        if (is(Object, ns)) return Object_put(ns, key, val); // define a namespace variable
+    }
+    return _get(key, Symbol,value) = val; // set a global variable
 }
 
 oop Object_put(oop obj, oop key, oop val)
@@ -1536,33 +1541,101 @@ extern inline oop mkptr(void *address)
     return o;
 }
 
-oop newRefSym(oop name)
+oop newRefLocal(oop name)
+{
+    oop o = new(pRefLocal);
+    Object_put(o, sym_name, name);
+    return o;
+}
+
+oop RefLocal_eval(oop exp, oop env)
+{
+    if (!is(Object, env)) valueError("local", "not in a local scope", exp);
+    oop  sym = Object_get(exp, sym_name);
+    oop *ref = Object_refLocal(env, sym);
+    if (!ref) undefinedError(sym);
+    return mkptr(ref);
+}
+
+void RefLocal_codeOn(oop exp, oop str, oop env)
+{
+    String_appendAll(str, "local ");
+    printOn(str, Object_get(exp, sym_name), 0);
+}
+
+oop newGetLocal(oop name)
+{
+    oop o = new(pGetLocal);
+    Object_put(o, sym_name, name);
+    return o;
+}
+
+oop  GetLocal_eval(oop exp, oop env)
+{
+    if (!is(Object, env)) valueError("local", "not in a local scope", exp);
+    oop  sym = Object_get(exp, sym_name);
+    oop *ref = Object_refLocal(env, sym);
+    if (!ref) undefinedError(sym);
+    return *ref;
+}
+
+void GetLocal_codeOn(oop exp, oop str, oop env)
+{
+    String_appendAll(str, "local ");
+    printOn(str, Object_get(exp, sym_name), 0);
+}
+
+oop newSetLocal(oop name, oop value)
+{
+    oop o = new(pSetLocal);
+    Object_put(o, sym_name,  name);
+    Object_put(o, sym_value, value);
+    return o;
+}
+
+oop SetLocal_eval(oop exp, oop env)
+{
+    if (!is(Object, env)) valueError("local", "not in a local scope", exp);
+    oop sym =      Object_get(exp, sym_name );
+    oop val = eval(Object_get(exp, sym_value), env);
+    return Object_put(env, sym, val);
+}
+
+void SetLocal_codeOn(oop exp, oop str, oop env)
+{
+    String_appendAll(str, "local ");
+    printOn(str, Object_get(exp, sym_name), 0);
+    String_appendAll(str, " = ");
+    codeOn(str, Object_get(exp, sym_value), 0);
+}
+
+oop newRefGlobal(oop name)
 {
-    oop o = new(pRefSym);
+    oop o = new(pRefGlobal);
     Object_put(o, sym_name, name);
     return o;
 }
 
-oop RefSym_eval(oop exp, oop env)
+oop RefGlobal_eval(oop exp, oop env)
 {
     oop sym = Object_get(exp, sym_name);
     return mkptr(&_get(sym, Symbol,value));
 }
 
-void RefSym_codeOn(oop exp, oop str, oop env)
+void RefGlobal_codeOn(oop exp, oop str, oop env)
 {
     String_appendAll(str, "global ");
     printOn(str, Object_get(exp, sym_name), 0);
 }
 
-oop newGetSym(oop name)
+oop newGetGlobal(oop name)
 {
-    oop o = new(pGetSym);
+    oop o = new(pGetGlobal);
     Object_put(o, sym_name, name);
     return o;
 }
 
-oop  GetSym_eval(oop exp, oop env)
+oop  GetGlobal_eval(oop exp, oop env)
 {
     oop sym = Object_get(exp, sym_name);
     oop val = _get(sym, Symbol,value);
@@ -1570,28 +1643,28 @@ oop  GetSym_eval(oop exp, oop env)
     return val;
 }
 
-void GetSym_codeOn(oop exp, oop str, oop env)
+void GetGlobal_codeOn(oop exp, oop str, oop env)
 {
     String_appendAll(str, "global ");
     printOn(str, Object_get(exp, sym_name), 0);
 }
 
-oop newSetSym(oop name, oop value)
+oop newSetGlobal(oop name, oop value)
 {
-    oop o = new(pSetSym);
+    oop o = new(pSetGlobal);
     Object_put(o, sym_name,  name);
     Object_put(o, sym_value, value);
     return o;
 }
 
-oop SetSym_eval(oop exp, oop env)
+oop SetGlobal_eval(oop exp, oop env)
 {
     oop sym =      Object_get(exp, sym_name )      ;
     oop val = eval(Object_get(exp, sym_value), env);
     return _set(sym, Symbol,value, val);
 }
 
-void SetSym_codeOn(oop exp, oop str, oop env)
+void SetGlobal_codeOn(oop exp, oop str, oop env)
 {
     String_appendAll(str, "global ");
     printOn(str, Object_get(exp, sym_name), 0);
@@ -3067,10 +3140,11 @@ oop lvalue(oop rval)
 {
     if (!is(Object,rval)) valueError("=", "non-assignable value", rval);
     oop kind = _getDelegate(rval);
-    if      (kind == pGetVar  ) kind = pRefVar;
-    else if (kind == pGetProp ) kind = pRefProp;
-    else if (kind == pGetArray) kind = pRefArray;
-    else if (kind == pGetSym  ) kind = pRefSym;
+    if      (kind == pGetVar   ) kind = pRefVar;
+    else if (kind == pGetProp  ) kind = pRefProp;
+    else if (kind == pGetArray ) kind = pRefArray;
+    else if (kind == pGetLocal ) kind = pRefLocal;
+    else if (kind == pGetGlobal) kind = pRefGlobal;
     else valueError("=", "non-assignable value", rval);
     _setDelegate(rval, kind);
     return rval;
@@ -3083,7 +3157,6 @@ oop assign(oop rval, oop value)
     if      (kind == pGetVar  ) kind = pSetVar;
     else if (kind == pGetProp ) kind = pSetProp;
     else if (kind == pGetArray) kind = pSetArray;
-    else if (kind == pGetSym  ) kind = pSetSym;
     else valueError("=", "non-assignable value", rval);
     _setDelegate(rval, kind);
     Object_put(rval, sym_value, value);
@@ -3123,7 +3196,9 @@ stmt    = WHILE LPAREN c:expr RPAREN s:stmt     { $$ = newWhile(c, s) }
           | ENSURE e:stmt                       { $$ = newTryEnsure(t, e) }
           )
         | RAISE e:expr EOS                      { $$ = newRaise(e) }
-        |             i:id p:params b:block     { $$ = newSetVar(i, newLambda(p, b)) }
+        | LOCAL       i:id p:params b:block     { $$ = newSetLocal (i, newLambda(p, b)) }
+        | GLOBAL      i:id p:params b:block     { $$ = newSetGlobal(i, newLambda(p, b)) }
+        |             i:id p:params b:block     { $$ = newSetVar   (i, newLambda(p, b)) }
         | v:proto DOT i:id p:params b:block     { $$ = newSetProp(v, i, newLambda(p, b)) }
         | b:block                               { $$ = newBlock(b) }
         | e:expr EOS                            { $$ = e }
@@ -3133,7 +3208,9 @@ proto   = v:var ( DOT j:id !LPAREN              { v = newGetProp(v, j) }
 
 EOS     = SEMI+ | &RBRACE | &ELSE | &CATCH
 
-expr    = i:id ASSIGN e:expr                    { $$ = newSetVar(i, e) }
+expr    = LOCAL  i:id ASSIGN e:expr                    { $$ = newSetLocal (i, e) }
+        | GLOBAL i:id ASSIGN e:expr                    { $$ = newSetGlobal(i, e) }
+        |        i:id ASSIGN e:expr                    { $$ = newSetVar   (i, e) }
         | l:logor ( ASSIGN   r:expr             { l  = assign(l, r) }
                   | PLUSEQ   r:expr             { l  = newBinop(opPreAdd, lvalue(l), r) }
                   | MINUSEQ  r:expr             { l  = newBinop(opPreSub, lvalue(l), r) }
@@ -3271,8 +3348,9 @@ char    = "\\" ( ["'\\abfnrtv]
 
 symbol  = HASH i:id                             { $$ = i }
 
-var     = GLOBAL i:id                           { $$ = newGetSym(i) }
-        |        i:id                           { $$ = newGetVar(i) }
+var     = LOCAL  i:id                           { $$ = newGetLocal (i) }
+        | GLOBAL i:id                           { $$ = newGetGlobal(i) }
+        |        i:id                           { $$ = newGetVar   (i) }
 
 id      = < LETTER ALNUM* > -                   { $$ = intern(yytext) }
 
@@ -3308,6 +3386,7 @@ CATCH   = "catch"    !ALNUM  -
 ENSURE  = "ensure"   !ALNUM  -
 RAISE   = "raise"    !ALNUM  -
 GLOBAL  = "global"   !ALNUM  -
+LOCAL   = "local"    !ALNUM  -
 
 BQUOTE  = "`"           -
 COMMAT  = "@"           -