spec: gensym + symbol interning — *gensym-counter*, string->symbol, symbol->string, intern

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

hosts/javascript/platform.py

@@ -1663,6 +1663,8 @@ PLATFORM_JS_POST = '''
   var vectorLength = PRIMITIVES["vector-length"];
   var vectorRef = PRIMITIVES["vector-ref"];
   var reverse = PRIMITIVES["reverse"];
+  var stringToSymbol = PRIMITIVES["string->symbol"];
+  var symbolToString = PRIMITIVES["symbol->string"];
   function zip(a, b) { var r = []; for (var i = 0; i < Math.min(a.length, b.length); i++) r.push([a[i], b[i]]); return r; }
   function append_b(arr, x) { arr.push(x); return arr; }
   var apply = function(f, args) {

shared/static/scripts/sx-browser.js

@@ -31,7 +31,7 @@
   // =========================================================================
 
   var NIL = Object.freeze({ _nil: true, toString: function() { return "nil"; } });
-  var SX_VERSION = "2026-05-01T10:16:10Z";
+  var SX_VERSION = "2026-05-01T10:26:58Z";
 
   function isNil(x) { return x === NIL || x === null || x === undefined; }
   function isSxTruthy(x) { return x !== false && !isNil(x); }
@@ -810,6 +810,8 @@
   var vectorLength = PRIMITIVES["vector-length"];
   var vectorRef = PRIMITIVES["vector-ref"];
   var reverse = PRIMITIVES["reverse"];
+  var stringToSymbol = PRIMITIVES["string->symbol"];
+  var symbolToString = PRIMITIVES["symbol->string"];
   function zip(a, b) { var r = []; for (var i = 0; i < Math.min(a.length, b.length); i++) r.push([a[i], b[i]]); return r; }
   function append_b(arr, x) { arr.push(x); return arr; }
   var apply = function(f, args) {
@@ -3570,6 +3572,33 @@ PRIMITIVES["eval-expr"] = evalExpr;
   var trampoline = function(val) { return (isSxTruthy(isThunk(val)) ? evalExpr(thunkExpr(val), thunkEnv(val)) : val); };
 PRIMITIVES["trampoline"] = trampoline;
 
+  // *gensym-counter*
+  var _gensymCounter_ = 0;
+PRIMITIVES["*gensym-counter*"] = _gensymCounter_;
+
+  // gensym
+  var gensym = function() { var args = Array.prototype.slice.call(arguments, 0); return (function() {
+  var prefix = (isSxTruthy(isEmpty(args)) ? "g" : (String(first(args))));
+  return ((_gensymCounter_ = (_gensymCounter_ + 1)), makeSymbol((String(prefix) + String(_gensymCounter_))));
+})(); };
+PRIMITIVES["gensym"] = gensym;
+
+  // string->symbol
+  var stringToSymbol = function(s) { return makeSymbol(s); };
+PRIMITIVES["string->symbol"] = stringToSymbol;
+
+  // symbol->string
+  var symbolToString = function(sym) { return symbolName(sym); };
+PRIMITIVES["symbol->string"] = symbolToString;
+
+  // intern
+  var intern = function(s) { return makeSymbol(s); };
+PRIMITIVES["intern"] = intern;
+
+  // symbol-interned?
+  var symbolInterned_p = function(sym) { return true; };
+PRIMITIVES["symbol-interned?"] = symbolInterned_p;
+
 
   // === Transpiled from freeze (serializable state boundaries) ===
 

spec/evaluator.sx

@@ -4754,3 +4754,25 @@
   (fn
     (val)
     (if (thunk? val) (eval-expr (thunk-expr val) (thunk-env val)) val)))
+
+;; Phase 12: gensym + symbol interning
+
+(define *gensym-counter* 0)
+
+(define
+  gensym
+  (fn
+    (&rest args)
+    (let
+      ((prefix (if (empty? args) "g" (str (first args)))))
+      (do
+        (set! *gensym-counter* (+ *gensym-counter* 1))
+        (make-symbol (str prefix *gensym-counter*))))))
+
+(define string->symbol (fn (s) (make-symbol s)))
+
+(define symbol->string (fn (sym) (symbol-name sym)))
+
+(define intern (fn (s) (make-symbol s)))
+
+(define symbol-interned? (fn (sym) true))