Merge pull request #4274 from lydell/for-variables

Improve naming of generated 'i-variables'

lib/coffee-script/scope.js

@@ -66,13 +66,20 @@
     };
 
     Scope.prototype.temporary = function(name, index, single) {
+      var diff, endCode, letter, newCode, num, startCode;
       if (single == null) {
         single = false;
       }
       if (single) {
-        return (index + parseInt(name, 36)).toString(36).replace(/\d/g, 'a');
+        startCode = name.charCodeAt(0);
+        endCode = 'z'.charCodeAt(0);
+        diff = endCode - startCode;
+        newCode = startCode + index % (diff + 1);
+        letter = String.fromCharCode(newCode);
+        num = Math.floor(index / (diff + 1));
+        return "" + letter + (num || '');
       } else {
-        return name + (index || '');
+        return "" + name + (index || '');
       }
     };
 

src/scope.litcoffee

@@ -66,9 +66,15 @@ Generate a temporary variable name at the given index.
 
       temporary: (name, index, single=false) ->
         if single
-          (index + parseInt name, 36).toString(36).replace /\d/g, 'a'
+          startCode = name.charCodeAt(0)
+          endCode = 'z'.charCodeAt(0)
+          diff = endCode - startCode
+          newCode = startCode + index % (diff + 1)
+          letter = String.fromCharCode(newCode)
+          num = index // (diff + 1)
+          "#{letter}#{num or ''}"
         else
-          name + (index or '')
+          "#{name}#{index or ''}"
 
 Gets the type of a variable.
 

test/control_flow.coffee

@@ -464,3 +464,12 @@ test "#2367: super in for-loop", ->
       @sum
 
   eq 10, (new Bar).add 2, 3, 5
+
+test "#4267: lots of for-loops in the same scope", ->
+  # This used to include the invalid JavaScript `var do = 0`.
+  code = """
+    do ->
+      #{Array(200).join('for [0..0] then\n  ')}
+      true
+  """
+  ok CoffeeScript.eval(code)