From dc2f77e019c5245d4e767c6257ded1cc82383df5 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Tue, 21 Dec 2010 19:14:53 -0500
Subject: [PATCH] Allowing the fat arrow to be used in scoped loops.

---
 lib/nodes.js                    | 5 ++++-
 lib/rewriter.js                 | 2 +-
 src/nodes.coffee                | 4 +++-
 src/rewriter.coffee             | 2 +-
 test/test_comprehensions.coffee | 4 ++--
 5 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/nodes.js b/lib/nodes.js
index 39f56825..e7e4a641 100644
--- a/lib/nodes.js
+++ b/lib/nodes.js
@@ -42,7 +42,7 @@
     };
     Base.prototype.compileClosure = function(o) {
       if (this.containsPureStatement()) {
-        throw SyntaxError('cannot include a pure statement in an expression.');
+        throw SyntaxError('cannot use a pure statement in an expression.');
       }
       o.sharedScope = true;
       return Closure.wrap(this).compileNode(o);
@@ -1799,6 +1799,9 @@
       guardPart = '';
       defPart = '';
       idt1 = this.tab + TAB;
+      if (this.scoped && this.containsPureStatement()) {
+        throw SyntaxError('cannot use a pure statement in a scoped loop.');
+      }
       if (this.range) {
         forPart = source.compile(merge(o, {
           index: ivar,
diff --git a/lib/rewriter.js b/lib/rewriter.js
index f0bfd877..e7f063c8 100644
--- a/lib/rewriter.js
+++ b/lib/rewriter.js
@@ -176,7 +176,7 @@
         if (prev && !prev.spaced && tag === '?') {
           token.call = true;
         }
-        if (!(callObject || (prev != null ? prev.spaced : void 0) && (prev.call || (_ref3 = prev[0], __indexOf.call(IMPLICIT_FUNC, _ref3) >= 0)) && (__indexOf.call(IMPLICIT_CALL, tag) >= 0 || !(token.spaced || token.newLine) && __indexOf.call(IMPLICIT_UNSPACED_CALL, tag) >= 0) && !(seenFor && tag === '->' && next && next[0] === 'INDENT'))) {
+        if (!(callObject || (prev != null ? prev.spaced : void 0) && (prev.call || (_ref3 = prev[0], __indexOf.call(IMPLICIT_FUNC, _ref3) >= 0)) && (__indexOf.call(IMPLICIT_CALL, tag) >= 0 || !(token.spaced || token.newLine) && __indexOf.call(IMPLICIT_UNSPACED_CALL, tag) >= 0) && !(seenFor && (tag === '->' || tag === '=>') && next && next[0] === 'INDENT'))) {
           return 1;
         }
         tokens.splice(i, 0, ['CALL_START', '(', token[2]]);
diff --git a/src/nodes.coffee b/src/nodes.coffee
index 22a15bf9..3d91f019 100644
--- a/src/nodes.coffee
+++ b/src/nodes.coffee
@@ -49,7 +49,7 @@ exports.Base = class Base
   # object with their parent closure, to preserve the expected lexical scope.
   compileClosure: (o) ->
     if @containsPureStatement()
-      throw SyntaxError 'cannot include a pure statement in an expression.'
+      throw SyntaxError 'cannot use a pure statement in an expression.'
     o.sharedScope = yes
     Closure.wrap(this).compileNode o
 
@@ -1454,6 +1454,8 @@ exports.For = class For extends Base
     guardPart     = ''
     defPart       = ''
     idt1          = @tab + TAB
+    if @scoped and @containsPureStatement()
+      throw SyntaxError 'cannot use a pure statement in a scoped loop.'
     if @range
       forPart = source.compile merge(o, {index: ivar, @step})
     else
diff --git a/src/rewriter.coffee b/src/rewriter.coffee
index 3e1e641e..74eb9f7a 100644
--- a/src/rewriter.coffee
+++ b/src/rewriter.coffee
@@ -148,7 +148,7 @@ class exports.Rewriter
       return 1 unless callObject or
         prev?.spaced and (prev.call or prev[0] in IMPLICIT_FUNC) and
         (tag in IMPLICIT_CALL or not (token.spaced or token.newLine) and tag in IMPLICIT_UNSPACED_CALL) and
-        not (seenFor and tag is '->' and next and next[0] is 'INDENT')
+        not (seenFor and tag in ['->', '=>'] and next and next[0] is 'INDENT')
       tokens.splice i, 0, ['CALL_START', '(', token[2]]
       @detectEnd i + 1, (token, i) ->
         return yes if not seenSingle and token.fromThen
diff --git a/test/test_comprehensions.coffee b/test/test_comprehensions.coffee
index ef38a69e..1d4c2808 100644
--- a/test/test_comprehensions.coffee
+++ b/test/test_comprehensions.coffee
@@ -139,8 +139,8 @@ ok(num % 2 is 0 for num in array by 2)
 
 # Nested shared scopes.
 foo = ->
-  for i in [0..7] ->
-    for j in [0..7] ->
+  for i in [0..7] =>
+    for j in [0..7] =>
       -> i + j
 
 eq foo()[3][4](), 7