fix merging scopes #43 + unit tests

README.md

@@ -1,7 +1,7 @@
 ![LIPS - Scheme Based Powerful Lisp Language](https://github.com/jcubic/lips/blob/devel/assets/lips.svg?raw=true)
 
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+[![travis](https://travis-ci.org/jcubic/lips.svg?branch=devel&8a79b0ab4e39edc3cf6c74d74c3251aa8bbeee8f)](https://travis-ci.org/jcubic/lips)
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 [![Join Gitter Chat](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/jcubic/lips)
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dist/lips.js

@@ -31,7 +31,7 @@
  * Copyright (c) 2014-present, Facebook, Inc.
  * released under MIT license
  *
- * build: Thu, 17 Sep 2020 10:51:46 +0000
+ * build: Thu, 17 Sep 2020 16:04:51 +0000
  */
 (function () {
   'use strict';
@@ -3138,6 +3138,8 @@
     // :: that will show symbols
     // ----------------------------------------------------------------------
 
+    /* istanbul ignore next */
+
     function symbolize(obj) {
       if (obj && _typeof_1(obj) === 'object') {
         var result = {};
@@ -4260,22 +4262,21 @@
 
       function rename(name) {
         if (!gensyms[name]) {
-          var value = scope.get(name, {
-            throwError: false
-          });
-          var gensym_name = gensym(name); // keep names so they can be restored after evaluation
+          var ref = scope.ref(name);
+          var gensym_name = gensym(name);
+
+          if (ref) {
+            var value = scope.get(name);
+            scope.set(gensym_name, value);
+          } // keep names so they can be restored after evaluation
           // if there are free symbols as output
           // kind of hack
 
+
           names.push({
             name: name,
             gensym: gensym_name
           });
-
-          if (typeof value !== 'undefined') {
-            scope.set(gensym_name, value);
-          }
-
           gensyms[name] = gensym_name;
         }
 
@@ -8314,7 +8315,17 @@
             dynamic_scope = scope;
           }
 
-          var var_scope = this;
+          var var_scope = this; // for macros that define variables used in macro (2 levels nestting)
+
+          if (var_scope.name === Syntax.merge_env) {
+            // copy refs for defined gynsyms
+            var props = Object.getOwnPropertySymbols(var_scope.env);
+            props.forEach(function (symbol) {
+              var_scope.parent.set(symbol, var_scope.env[symbol]);
+            });
+            var_scope = var_scope.parent;
+          }
+
           var eval_args = {
             env: scope,
             dynamic_scope: dynamic_scope,
@@ -10436,10 +10447,10 @@
 
     var banner = function () {
       // Rollup tree-shaking is removing the variable if it's normal string because
-      // obviously 'Thu, 17 Sep 2020 10:51:46 +0000' == '{{' + 'DATE}}'; can be removed
+      // obviously 'Thu, 17 Sep 2020 16:04:51 +0000' == '{{' + 'DATE}}'; can be removed
       // but disablig Tree-shaking is adding lot of not used code so we use this
       // hack instead
-      var date = LString('Thu, 17 Sep 2020 10:51:46 +0000').valueOf();
+      var date = LString('Thu, 17 Sep 2020 16:04:51 +0000').valueOf();
 
       var _date = date === '{{' + 'DATE}}' ? new Date() : new Date(date);
 
@@ -10476,7 +10487,7 @@
     var lips = {
       version: 'DEV',
       banner: banner,
-      date: 'Thu, 17 Sep 2020 10:51:46 +0000',
+      date: 'Thu, 17 Sep 2020 16:04:51 +0000',
       exec: exec,
       parse: parse,
       tokenize: tokenize,

src/lips.js

@@ -1805,6 +1805,7 @@
     // :: debug function that can be used with JSON.stringify
     // :: that will show symbols
     // ----------------------------------------------------------------------
+    /* istanbul ignore next */
     function symbolize(obj) {
         if (obj && typeof obj === 'object') {
             var result = {};
@@ -2646,17 +2647,18 @@
         }
         function rename(name) {
             if (!gensyms[name]) {
-                var value = scope.get(name, { throwError: false });
+                var ref = scope.ref(name);
                 const gensym_name = gensym(name);
+                if (ref) {
+                    const value = scope.get(name);
+                    scope.set(gensym_name, value);
+                }
                 // keep names so they can be restored after evaluation
                 // if there are free symbols as output
                 // kind of hack
                 names.push({
                     name, gensym: gensym_name
                 });
-                if (typeof value !== 'undefined') {
-                    scope.set(gensym_name, value);
-                }
                 gensyms[name] = gensym_name;
             }
             return gensyms[name];
@@ -5852,6 +5854,15 @@
                     dynamic_scope = scope;
                 }
                 var var_scope = this;
+                // for macros that define variables used in macro (2 levels nestting)
+                if (var_scope.name === Syntax.merge_env) {
+                    // copy refs for defined gynsyms
+                    const props = Object.getOwnPropertySymbols(var_scope.env);
+                    props.forEach(symbol => {
+                        var_scope.parent.set(symbol, var_scope.env[symbol]);
+                    });
+                    var_scope = var_scope.parent;
+                }
                 var eval_args = { env: scope, dynamic_scope, error };
                 let ellipsis, rules, symbols;
                 if (macro.car instanceof LSymbol) {

tests/syntax.scm

@@ -692,3 +692,49 @@
         (t.is (to.throw ((lambda (++)
                            (foo 1 ++ 2)) 10))
               true)))
+
+(test "syntax: scope with rewriting"
+      (lambda (t)
+        ;; ref: https://www.cs.utah.edu/plt/scope-sets/
+        (define self (letrec-syntax ([identity (syntax-rules ()
+                                                 [(_ misc-id)
+                                                  (lambda (x)
+                                                    (let ([misc-id 'other])
+                                                      x))])])
+                       (identity x)))
+        (t.is (self 10) 10)
+
+        ;; racket macro
+        (define-syntax define-syntax-rule
+          (syntax-rules ()
+            ((_ (name args ...) body)
+             (define-syntax name (syntax-rules () ((name args ...) body))))))
+
+        (define-syntax-rule (define-other-five misc-id)
+          (begin
+            (define x 5)
+            misc-id))
+
+        (t.is (to.throw (define-other-five x)) true)))
+
+(test "syntax: define syntax macro inside syntax-macro"
+      (lambda (t)
+
+        (define-syntax def (syntax-rules () ((_ x y ) (define x y))))
+        (define-syntax def-2 (syntax-rules () ((_ x y) (def x y))))
+
+        (def foo 10)
+        (def-2 bar 20)
+        (t.is (+ foo bar) 30)))
+
+(test_ "syntax: free variables"
+      (lambda (t)
+        (define-syntax def (syntax-rules ()
+                             ((_ foo bar)
+                              (begin
+                                (define foo bar)
+                                hello))))
+
+        (t.is (def hello 10) 10)
+        (def hello 10)
+        (t.is hello 10)))