From aac96792820a3212f0c592b71bce50e7ad3002b1 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Mon, 19 Apr 2010 23:18:39 -0400
Subject: [PATCH] merging in gfodor's excellent Rewriter patch.

---
 lib/rewriter.js           | 16 ++++++++++++----
 src/rewriter.coffee       | 19 ++++++++-----------
 test/test_chaining.coffee |  5 +++--
 3 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/lib/rewriter.js b/lib/rewriter.js
index 5b278246..1a5c5bb7 100644
--- a/lib/rewriter.js
+++ b/lib/rewriter.js
@@ -285,6 +285,8 @@
     //    it with the inverse of what we've just popped.
     // 3. Keep track of "debt" for tokens that we manufacture, to make sure we end
     //    up balanced in the end.
+    // 4. Be careful not to alter array or parentheses delimiters with overzealous
+    //    rewriting.
     Rewriter.prototype.rewrite_closing_parens = function rewrite_closing_parens() {
       var _a, debt, key, stack, val;
       stack = [];
@@ -295,7 +297,7 @@
         (debt[key] = 0);
       }}
       return this.scan_tokens(__bind(function(prev, token, post, i) {
-          var inv, match, mtag, tag;
+          var inv, match, mtag, oppos, tag;
           tag = token[0];
           inv = INVERSES[token[0]];
           if (include(EXPRESSION_START, tag)) {
@@ -309,12 +311,18 @@
             } else {
               match = stack.pop();
               mtag = match[0];
-              if (tag === INVERSES[mtag]) {
+              oppos = INVERSES[mtag];
+              if (tag === oppos) {
                 return 1;
               }
               debt[mtag] += 1;
-              val = mtag === 'INDENT' ? match[1] : INVERSES[mtag];
-              this.tokens.splice(i, 0, [INVERSES[mtag], val]);
+              val = [oppos, mtag === 'INDENT' ? match[1] : oppos];
+              if ((this.tokens[i + 2] == undefined ? undefined : this.tokens[i + 2][0]) === mtag) {
+                this.tokens.splice(i + 3, 0, val);
+                stack.push(match);
+              } else {
+                this.tokens.splice(i, 0, val);
+              }
               return 1;
             }
           } else {
diff --git a/src/rewriter.coffee b/src/rewriter.coffee
index 8ebe38ff..670b0c62 100644
--- a/src/rewriter.coffee
+++ b/src/rewriter.coffee
@@ -209,7 +209,8 @@ exports.Rewriter: class Rewriter
   #    it with the inverse of what we've just popped.
   # 3. Keep track of "debt" for tokens that we manufacture, to make sure we end
   #    up balanced in the end.
-  #
+  # 4. Be careful not to alter array or parentheses delimiters with overzealous
+  #    rewriting.
   rewrite_closing_parens: ->
     stack: []
     debt:  {}
@@ -228,19 +229,15 @@ exports.Rewriter: class Rewriter
         else
           match: stack.pop()
           mtag:  match[0]
-          return 1 if tag is INVERSES[mtag]
+          oppos: INVERSES[mtag]
+          return 1 if tag is oppos
           debt[mtag]: + 1
-          val: if mtag is 'INDENT' then match[1] else INVERSES[mtag]
-
-          # Edge case, lookahead and if we are inserting in front of a
-          # subsequent opening token, insert ahead of it and re-queue onto
-          # stack.
-          if @tokens[i + 2]?[0] == mtag
-            @tokens.splice i + 3, 0, [INVERSES[mtag], val]
+          val: [oppos, if mtag is 'INDENT' then match[1] else oppos]
+          if @tokens[i + 2]?[0] is mtag
+            @tokens.splice i + 3, 0, val
             stack.push(match)
           else
-            @tokens.splice i, 0, [INVERSES[mtag], val]
-
+            @tokens.splice i, 0, val
           return 1
       else
         return 1
diff --git a/test/test_chaining.coffee b/test/test_chaining.coffee
index 30a618c3..040418d7 100644
--- a/test/test_chaining.coffee
+++ b/test/test_chaining.coffee
@@ -35,12 +35,13 @@ six:
 
 ok six is 6
 
-# Bug due to rewriting issue with indented array literals
+
+# Ensure that indented array literals don't trigger whitespace rewriting.
 func: () ->
   ok arguments.length is 1
 
 func(
-  [[[[[], 
+  [[[[[],
                 []],
               [[]]]],
     []])