diff --git a/lib/lexer.js b/lib/lexer.js
index c41ecc53..496dd067 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -1,5 +1,5 @@
 (function(){
-  var ACCESSORS, ASSIGNMENT, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_KEYWORDS, COMMENT, COMMENT_CLEANER, CONVERSIONS, HALF_ASSIGNMENTS, HEREDOC, HEREDOC_INDENT, IDENTIFIER, INTERPOLATION, JS_CLEANER, JS_FORBIDDEN, JS_KEYWORDS, KEYWORDS, LAST_DENT, LAST_DENTS, LINE_BREAK, Lexer, MULTILINER, MULTI_DENT, NOT_REGEX, NO_NEWLINE, NUMBER, OPERATOR, REGEX_ESCAPE, REGEX_FLAGS, REGEX_INTERPOLATION, REGEX_START, RESERVED, Rewriter, STRING_NEWLINES, WHITESPACE, _a, balanced_string, compact, count, helpers, include, starts;
+  var ACCESSORS, ASSIGNMENT, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_KEYWORDS, COMMENT, COMMENT_CLEANER, CONVERSIONS, HALF_ASSIGNMENTS, HEREDOC, HEREDOC_INDENT, IDENTIFIER, INTERPOLATION, JS_CLEANER, JS_FORBIDDEN, JS_KEYWORDS, KEYWORDS, LAST_DENT, LAST_DENTS, LINE_BREAK, Lexer, MULTILINER, MULTI_DENT, NOT_REGEX, NO_NEWLINE, NUMBER, OPERATOR, REGEX_ESCAPE, REGEX_FLAGS, REGEX_INTERPOLATION, REGEX_START, RESERVED, Rewriter, STRING_NEWLINES, WHITESPACE, _a, _b, _c, balanced_string, compact, count, helpers, include, starts;
   var __slice = Array.prototype.slice;
   // The CoffeeScript Lexer. Uses a series of token-matching regexes to attempt
   // matches against the beginning of the source code. When a match is found,
@@ -9,20 +9,22 @@
   // Which is a format that can be fed directly into [Jison](http://github.com/zaach/jison).
   // Set up the Lexer for both Node.js and the browser, depending on where we are.
   if ((typeof process !== "undefined" && process !== null)) {
-    Rewriter = require('./rewriter').Rewriter;
-    helpers = require('./helpers').helpers;
+    _a = require('./rewriter');
+    Rewriter = _a.Rewriter;
+    _b = require('./helpers');
+    helpers = _b.helpers;
   } else {
     this.exports = this;
     Rewriter = this.Rewriter;
     helpers = this.helpers;
   }
   // Import the helpers we need.
-  _a = helpers;
-  include = _a.include;
-  count = _a.count;
-  starts = _a.starts;
-  compact = _a.compact;
-  balanced_string = _a.balanced_string;
+  _c = helpers;
+  include = _c.include;
+  count = _c.count;
+  starts = _c.starts;
+  compact = _c.compact;
+  balanced_string = _c.balanced_string;
   // The Lexer Class
   // ---------------
   // The Lexer class reads a stream of CoffeeScript and divvys it up into tagged
@@ -107,10 +109,10 @@
     // Language extensions get the highest priority, first chance to tag tokens
     // as something else.
     Lexer.prototype.extension_token = function extension_token() {
-      var _b, _c, _d, extension;
-      _c = Lexer.extensions;
-      for (_b = 0, _d = _c.length; _b < _d; _b++) {
-        extension = _c[_b];
+      var _d, _e, _f, extension;
+      _e = Lexer.extensions;
+      for (_d = 0, _f = _e.length; _d < _f; _d++) {
+        extension = _e[_d];
         if (extension.call(this)) {
           return true;
         }
@@ -420,7 +422,7 @@
     // definitions versus argument lists in function calls. Walk backwards, tagging
     // parameters specially in order to make things easier for the parser.
     Lexer.prototype.tag_parameters = function tag_parameters() {
-      var _b, i, tok;
+      var _d, i, tok;
       if (this.tag() !== ')') {
         return null;
       }
@@ -431,11 +433,11 @@
         if (!tok) {
           return null;
         }
-        if ((_b = tok[0]) === 'IDENTIFIER') {
+        if ((_d = tok[0]) === 'IDENTIFIER') {
           tok[0] = 'PARAM';
-        } else if (_b === ')') {
+        } else if (_d === ')') {
           tok[0] = 'PARAM_END';
-        } else if (_b === '(' || _b === 'CALL_START') {
+        } else if (_d === '(' || _d === 'CALL_START') {
           tok[0] = 'PARAM_START';
           return tok[0];
         }
@@ -465,23 +467,23 @@
     // new Lexer, tokenize the interpolated contents, and merge them into the
     // token stream.
     Lexer.prototype.interpolate_string = function interpolate_string(str, escape_quotes) {
-      var _b, _c, _d, _e, _f, _g, _h, escaped, expr, group, i, idx, inner, interp, interpolated, lexer, match, nested, pi, quote, tag, tok, token, tokens, value;
+      var _d, _e, _f, _g, _h, _i, _j, escaped, expr, group, i, idx, inner, interp, interpolated, lexer, match, nested, pi, quote, tag, tok, token, tokens, value;
       if (str.length < 3 || !starts(str, '"')) {
         return this.token('STRING', str);
       } else {
         lexer = new Lexer();
         tokens = [];
         quote = str.substring(0, 1);
-        _b = [1, 1];
-        i = _b[0];
-        pi = _b[1];
+        _d = [1, 1];
+        i = _d[0];
+        pi = _d[1];
         while (i < str.length - 1) {
           if (starts(str, '\\', i)) {
             i += 1;
           } else if ((match = str.substring(i).match(INTERPOLATION))) {
-            _c = match;
-            group = _c[0];
-            interp = _c[1];
+            _e = match;
+            group = _e[0];
+            interp = _e[1];
             if (starts(interp, '@')) {
               interp = ("this." + (interp.substring(1)));
             }
@@ -500,9 +502,9 @@
               nested = lexer.tokenize(("(" + inner + ")"), {
                 line: this.line
               });
-              _d = nested;
-              for (idx = 0, _e = _d.length; idx < _e; idx++) {
-                tok = _d[idx];
+              _f = nested;
+              for (idx = 0, _g = _f.length; idx < _g; idx++) {
+                tok = _f[idx];
                 tok[0] === 'CALL_END' ? (tok[0] = ')') : null;
               }
               nested.pop();
@@ -525,12 +527,12 @@
         if (interpolated) {
           this.token('(', '(');
         }
-        _f = tokens;
-        for (i = 0, _g = _f.length; i < _g; i++) {
-          token = _f[i];
-          _h = token;
-          tag = _h[0];
-          value = _h[1];
+        _h = tokens;
+        for (i = 0, _i = _h.length; i < _i; i++) {
+          token = _h[i];
+          _j = token;
+          tag = _j[0];
+          value = _j[1];
           if (tag === 'TOKENS') {
             this.tokens = this.tokens.concat(value);
           } else if (tag === 'STRING' && escape_quotes) {
diff --git a/lib/rewriter.js b/lib/rewriter.js
index a7799741..ece25817 100644
--- a/lib/rewriter.js
+++ b/lib/rewriter.js
@@ -1,5 +1,5 @@
 (function(){
-  var BALANCED_PAIRS, EXPRESSION_CLOSE, EXPRESSION_END, EXPRESSION_START, IMPLICIT_BLOCK, IMPLICIT_CALL, IMPLICIT_END, IMPLICIT_FUNC, INVERSES, Rewriter, SINGLE_CLOSERS, SINGLE_LINERS, _a, _b, _c, _d, _e, _f, _g, _h, _i, _j, _k, _l, helpers, include, pair;
+  var BALANCED_PAIRS, EXPRESSION_CLOSE, EXPRESSION_END, EXPRESSION_START, IMPLICIT_BLOCK, IMPLICIT_CALL, IMPLICIT_END, IMPLICIT_FUNC, INVERSES, Rewriter, SINGLE_CLOSERS, SINGLE_LINERS, _a, _b, _c, _d, _e, _f, _g, _h, _i, _j, _k, _l, _m, helpers, include, pair;
   var __slice = Array.prototype.slice, __bind = function(func, obj, args) {
     return function() {
       return func.apply(obj || {}, args ? args.concat(__slice.call(arguments, 0)) : arguments);
@@ -13,14 +13,15 @@
   // parentheses, balance incorrect nestings, and generally clean things up.
   // Set up exported variables for both Node.js and the browser.
   if ((typeof process !== "undefined" && process !== null)) {
-    helpers = require('./helpers').helpers;
+    _a = require('./helpers');
+    helpers = _a.helpers;
   } else {
     this.exports = this;
     helpers = this.helpers;
   }
   // Import the helpers we need.
-  _a = helpers;
-  include = _a.include;
+  _b = helpers;
+  include = _b.include;
   // The **Rewriter** class is used by the [Lexer](lexer.html), directly against
   // its internal array of tokens.
   exports.Rewriter = (function() {
@@ -63,13 +64,13 @@
     // correctly indented, or appear on a line of their own.
     Rewriter.prototype.adjust_comments = function adjust_comments() {
       return this.scan_tokens(__bind(function(prev, token, post, i) {
-          var _b, after, before;
+          var _c, after, before;
           if (!(token[0] === 'COMMENT')) {
             return 1;
           }
-          _b = [this.tokens[i - 2], this.tokens[i + 2]];
-          before = _b[0];
-          after = _b[1];
+          _c = [this.tokens[i - 2], this.tokens[i + 2]];
+          before = _c[0];
+          after = _c[1];
           if (after && after[0] === 'INDENT') {
             this.tokens.splice(i + 2, 1);
             before && before[0] === 'OUTDENT' && post && (prev[0] === post[0]) && (post[0] === 'TERMINATOR') ? this.tokens.splice(i - 2, 1) : this.tokens.splice(i, 0, after);
@@ -85,12 +86,12 @@
     // Leading newlines would introduce an ambiguity in the grammar, so we
     // dispatch them here.
     Rewriter.prototype.remove_leading_newlines = function remove_leading_newlines() {
-      var _b;
-      _b = [];
+      var _c;
+      _c = [];
       while (this.tokens[0] && this.tokens[0][0] === 'TERMINATOR') {
-        _b.push(this.tokens.shift());
+        _c.push(this.tokens.shift());
       }
-      return _b;
+      return _c;
     };
     // Some blocks occur in the middle of expressions -- when we're expecting
     // this, remove their trailing newlines.
@@ -111,23 +112,23 @@
       parens = [0];
       brackets = [0];
       return this.scan_tokens(__bind(function(prev, token, post, i) {
-          var _b;
-          if ((_b = token[0]) === 'CALL_START') {
+          var _c;
+          if ((_c = token[0]) === 'CALL_START') {
             parens.push(0);
-          } else if (_b === 'INDEX_START') {
+          } else if (_c === 'INDEX_START') {
             brackets.push(0);
-          } else if (_b === '(') {
+          } else if (_c === '(') {
             parens[parens.length - 1] += 1;
-          } else if (_b === '[') {
+          } else if (_c === '[') {
             brackets[brackets.length - 1] += 1;
-          } else if (_b === ')') {
+          } else if (_c === ')') {
             if (parens[parens.length - 1] === 0) {
               parens.pop();
               token[0] = 'CALL_END';
             } else {
               parens[parens.length - 1] -= 1;
             }
-          } else if (_b === ']') {
+          } else if (_c === ']') {
             if (brackets[brackets.length - 1] === 0) {
               brackets.pop();
               token[0] = 'INDEX_END';
@@ -145,9 +146,9 @@
       var close_calls, stack;
       stack = [0];
       close_calls = __bind(function(i) {
-          var _b, _c, _d, size, tmp;
-          _c = 0; _d = stack[stack.length - 1];
-          for (_b = 0, tmp = _c; (_c <= _d ? tmp < _d : tmp > _d); (_c <= _d ? tmp += 1 : tmp -= 1), _b++) {
+          var _c, _d, _e, size, tmp;
+          _d = 0; _e = stack[stack.length - 1];
+          for (_c = 0, tmp = _d; (_d <= _e ? tmp < _e : tmp > _e); (_d <= _e ? tmp += 1 : tmp -= 1), _c++) {
             this.tokens.splice(i, 0, ['CALL_END', ')', this.tokens[i][2]]);
           }
           size = stack[stack.length - 1] + 1;
@@ -155,7 +156,7 @@
           return size;
         }, this);
       return this.scan_tokens(__bind(function(prev, token, post, i) {
-          var open, size, tag;
+          var j, nx, open, size, tag;
           tag = token[0];
           if (tag === 'OUTDENT') {
             stack[stack.length - 2] += stack.pop();
@@ -179,11 +180,21 @@
             return 1;
           }
           if (open && !token.generated && (!post || include(IMPLICIT_END, tag))) {
-            size = close_calls(i);
-            if (tag !== 'OUTDENT' && include(EXPRESSION_END, tag)) {
-              stack.pop();
+            j = 1;
+            while ((typeof (nx = this.tokens[i + j]) !== "undefined" && (nx = this.tokens[i + j]) !== null) && include(IMPLICIT_END, nx[0])) {
+              j++;
+            }
+            if ((typeof nx !== "undefined" && nx !== null) && nx[0] === ',') {
+              if (tag === 'TERMINATOR') {
+                this.tokens.splice(i, 1);
+              }
+            } else {
+              size = close_calls(i);
+              if (tag !== 'OUTDENT' && include(EXPRESSION_END, tag)) {
+                stack.pop();
+              }
+              return size;
             }
-            return size;
           }
           if (tag !== 'OUTDENT' && include(EXPRESSION_END, tag)) {
             stack[stack.length - 2] += stack.pop();
@@ -236,17 +247,17 @@
     // Ensure that all listed pairs of tokens are correctly balanced throughout
     // the course of the token stream.
     Rewriter.prototype.ensure_balance = function ensure_balance(pairs) {
-      var _b, _c, key, levels, line, open, open_line, unclosed, value;
+      var _c, _d, key, levels, line, open, open_line, unclosed, value;
       levels = {};
       open_line = {};
       this.scan_tokens(__bind(function(prev, token, post, i) {
-          var _b, _c, _d, _e, close, open, pair;
-          _c = pairs;
-          for (_b = 0, _d = _c.length; _b < _d; _b++) {
-            pair = _c[_b];
-            _e = pair;
-            open = _e[0];
-            close = _e[1];
+          var _c, _d, _e, _f, close, open, pair;
+          _d = pairs;
+          for (_c = 0, _e = _d.length; _c < _e; _c++) {
+            pair = _d[_c];
+            _f = pair;
+            open = _f[0];
+            close = _f[1];
             levels[open] = levels[open] || 0;
             if (token[0] === open) {
               if (levels[open] === 0) {
@@ -264,12 +275,12 @@
           return 1;
         }, this));
       unclosed = (function() {
-        _b = []; _c = levels;
-        for (key in _c) { if (__hasProp.call(_c, key)) {
-          value = _c[key];
-          value > 0 ? _b.push(key) : null;
+        _c = []; _d = levels;
+        for (key in _d) { if (__hasProp.call(_d, key)) {
+          value = _d[key];
+          value > 0 ? _c.push(key) : null;
         }}
-        return _b;
+        return _c;
       })();
       if (unclosed.length) {
         open = unclosed[0];
@@ -291,12 +302,12 @@
     // 4. Be careful not to alter array or parentheses delimiters with overzealous
     //    rewriting.
     Rewriter.prototype.rewrite_closing_parens = function rewrite_closing_parens() {
-      var _b, debt, key, stack, val;
+      var _c, debt, key, stack, val;
       stack = [];
       debt = {};
-      _b = INVERSES;
-      for (key in _b) { if (__hasProp.call(_b, key)) {
-        val = _b[key];
+      _c = INVERSES;
+      for (key in _c) { if (__hasProp.call(_c, key)) {
+        val = _c[key];
         (debt[key] = 0);
       }}
       return this.scan_tokens(__bind(function(prev, token, post, i) {
@@ -342,29 +353,29 @@
   // The inverse mappings of `BALANCED_PAIRS` we're trying to fix up, so we can
   // look things up from either end.
   INVERSES = {};
-  _c = BALANCED_PAIRS;
-  for (_b = 0, _d = _c.length; _b < _d; _b++) {
-    pair = _c[_b];
+  _d = BALANCED_PAIRS;
+  for (_c = 0, _e = _d.length; _c < _e; _c++) {
+    pair = _d[_c];
     INVERSES[pair[0]] = pair[1];
     INVERSES[pair[1]] = pair[0];
   }
   // The tokens that signal the start of a balanced pair.
   EXPRESSION_START = (function() {
-    _e = []; _g = BALANCED_PAIRS;
-    for (_f = 0, _h = _g.length; _f < _h; _f++) {
-      pair = _g[_f];
-      _e.push(pair[0]);
+    _f = []; _h = BALANCED_PAIRS;
+    for (_g = 0, _i = _h.length; _g < _i; _g++) {
+      pair = _h[_g];
+      _f.push(pair[0]);
     }
-    return _e;
+    return _f;
   })();
   // The tokens that signal the end of a balanced pair.
   EXPRESSION_END = (function() {
-    _i = []; _k = BALANCED_PAIRS;
-    for (_j = 0, _l = _k.length; _j < _l; _j++) {
-      pair = _k[_j];
-      _i.push(pair[1]);
+    _j = []; _l = BALANCED_PAIRS;
+    for (_k = 0, _m = _l.length; _k < _m; _k++) {
+      pair = _l[_k];
+      _j.push(pair[1]);
     }
-    return _i;
+    return _j;
   })();
   // Tokens that indicate the close of a clause of an expression.
   EXPRESSION_CLOSE = ['CATCH', 'WHEN', 'ELSE', 'FINALLY'].concat(EXPRESSION_END);
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 0402d1c8..bece1a7e 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -9,8 +9,8 @@
 
 # Set up the Lexer for both Node.js and the browser, depending on where we are.
 if process?
-  Rewriter: require('./rewriter').Rewriter
-  helpers:  require('./helpers').helpers
+  {Rewriter}: require('./rewriter')
+  {helpers}:  require('./helpers')
 else
   this.exports: this
   Rewriter:     this.Rewriter
diff --git a/src/rewriter.coffee b/src/rewriter.coffee
index a54db5a9..f1fd91e3 100644
--- a/src/rewriter.coffee
+++ b/src/rewriter.coffee
@@ -7,7 +7,7 @@
 
 # Set up exported variables for both Node.js and the browser.
 if process?
-  helpers: require('./helpers').helpers
+  {helpers}: require('./helpers')
 else
   this.exports: this
   helpers:      this.helpers
@@ -135,9 +135,13 @@ exports.Rewriter: class Rewriter
         stack.push 0
         return 1
       if open and !token.generated and (!post or include(IMPLICIT_END, tag))
-        size: close_calls(i)
-        stack.pop() if tag isnt 'OUTDENT' and include EXPRESSION_END, tag
-        return size
+        j: 1; j++ while (nx: @tokens[i + j])? and include(IMPLICIT_END, nx[0])
+        if nx? and nx[0] is ','
+          @tokens.splice(i, 1) if tag is 'TERMINATOR'
+        else
+          size: close_calls(i)
+          stack.pop() if tag isnt 'OUTDENT' and include EXPRESSION_END, tag
+          return size
       if tag isnt 'OUTDENT' and include EXPRESSION_END, tag
         stack[stack.length - 2]: + stack.pop()
         return 1