From a5f69ef7160dccd5ba31dedc89b5f996ea964ef4 Mon Sep 17 00:00:00 2001
From: Stan Angeloff <insaned@abv.bg>
Date: Mon, 8 Mar 2010 09:31:31 +0200
Subject: [PATCH 01/10] Empty expression interpolations evaluate as empty
 strings now.

---
 lib/lexer.js                          | 20 ++++++++++++--------
 src/lexer.coffee                      | 13 ++++++++-----
 test/test_string_interpolation.coffee |  3 ++-
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/lib/lexer.js b/lib/lexer.js
index 161ae53b..fab26120 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -471,17 +471,21 @@
             tokens.push(['IDENTIFIER', interp]);
             i += group.length - 1;
             pi = i + 1;
-          } else if (((expr = this.balanced_string(str.substring(i), ['${', '}']))) && expr.length > 3) {
-            inner = expr.substring(2, expr.length - 1);
-            nested = lexer.tokenize("(" + inner + ")", {
-              rewrite: false,
-              line: this.line
-            });
-            nested.pop();
+          } else if (((expr = this.balanced_string(str.substring(i), ['${', '}'])))) {
             if (pi < i) {
               tokens.push(['STRING', quote + (str.substring(pi, i)) + quote]);
             }
-            tokens.push(['TOKENS', nested]);
+            inner = expr.substring(2, expr.length - 1);
+            if (inner.length) {
+              nested = lexer.tokenize("(" + inner + ")", {
+                rewrite: false,
+                line: this.line
+              });
+              nested.pop();
+              tokens.push(['TOKENS', nested]);
+            } else {
+              tokens.push(['STRING', quote + quote]);
+            }
             i += expr.length - 1;
             pi = i + 1;
           }
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 74c96d97..30ba0d9b 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -349,12 +349,15 @@ exports.Lexer: class Lexer
           tokens.push ['IDENTIFIER', interp]
           i += group.length - 1
           pi: i + 1
-        else if (expr: @balanced_string str.substring(i), ['${', '}']) and expr.length > 3
-          inner: expr.substring(2, expr.length - 1)
-          nested: lexer.tokenize "($inner)", {rewrite: no, line: @line}
-          nested.pop()
+        else if (expr: @balanced_string str.substring(i), ['${', '}'])
           tokens.push ['STRING', "$quote${ str.substring(pi, i) }$quote"] if pi < i
-          tokens.push ['TOKENS', nested]
+          inner: expr.substring(2, expr.length - 1)
+          if inner.length
+            nested: lexer.tokenize "($inner)", {rewrite: no, line: @line}
+            nested.pop()
+            tokens.push ['TOKENS', nested]
+          else
+            tokens.push ['STRING', "$quote$quote"]
           i += expr.length - 1
           pi: i + 1
         i += 1
diff --git a/test/test_string_interpolation.coffee b/test/test_string_interpolation.coffee
index 031ad543..5c454544 100644
--- a/test/test_string_interpolation.coffee
+++ b/test/test_string_interpolation.coffee
@@ -28,7 +28,8 @@ ok "Escaping \$last" is 'Escaping $last'
 ok "Escaping \${last}" is 'Escaping ${last}'
 
 ok "$$" is '$$'
-ok "${}" is '${}'
+ok "${}" is ''
+ok "${}A${} ${} ${}B${}" is 'A  B'
 ok "\\\\\$$" is '\\\\\$$'
 ok "\\\${}" is '\\${}'
 

From 5e52e7f19e5f563e3fda9af70156f4fccf693ae2 Mon Sep 17 00:00:00 2001
From: Chris Hoffman <cehoffman@gmail.com>
Date: Mon, 8 Mar 2010 08:02:23 -0600
Subject: [PATCH 02/10] While loop can be a single line expressions so don't
 indent when it is

---
 extras/CoffeeScript.tmbundle/Preferences/Indent.tmPreferences | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/extras/CoffeeScript.tmbundle/Preferences/Indent.tmPreferences b/extras/CoffeeScript.tmbundle/Preferences/Indent.tmPreferences
index 08e29612..b331f305 100644
--- a/extras/CoffeeScript.tmbundle/Preferences/Indent.tmPreferences
+++ b/extras/CoffeeScript.tmbundle/Preferences/Indent.tmPreferences
@@ -15,8 +15,8 @@
 		^\s*
 		(.*class
 		|[a-zA-Z\$_](\w|\$|:|\.)*\s*(?=\:(\s*\(.*\))?\s*((=|-)&gt;\s*$)) # function that is not one line
-		|[a-zA-Z\$_](\w|\$|\.)*\s*(?=(?!\::)\:(?!(\s*\(.*\))?\s*((=|-)&gt;))):\s*(if(?!.*?then)|while|for|$) # assignment using multiline if/while/for
-		|if(?!.*?then)|while|for
+		|[a-zA-Z\$_](\w|\$|\.)*\s*(?=(?!\::)\:(?!(\s*\(.*\))?\s*((=|-)&gt;))):\s*((if|while)(?!.*?then)|for|$) # assignment using multiline if/while/for
+		|(if|while)(?!.*?then)|for
 		|.*\{$
 		|.*\[$)</string>
 	</dict>

From 62a871773bd208353f8b5bec37fbc71554ab7bab Mon Sep 17 00:00:00 2001
From: Will <wdjingga@gmail.com>
Date: Tue, 9 Mar 2010 01:03:43 +1100
Subject: [PATCH 03/10] Include an extra line `process.mixin require 'sys'` on
 the top to let the .js output run using node (v0.1.31)

---
 examples/web_server.coffee | 1 +
 1 file changed, 1 insertion(+)

diff --git a/examples/web_server.coffee b/examples/web_server.coffee
index 8bf66d1d..b9927ef1 100644
--- a/examples/web_server.coffee
+++ b/examples/web_server.coffee
@@ -1,5 +1,6 @@
 # Contributed by Jason Huggins
 
+process.mixin require 'sys'
 http: require 'http'
 
 server: http.createServer (req, res) ->

From 81955005b9c3df3c8fba0ccea70475ff626d7deb Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Mon, 8 Mar 2010 09:13:15 -0500
Subject: [PATCH 04/10] doc tweaks

---
 documentation/index.html.erb | 6 +++---
 index.html                   | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/documentation/index.html.erb b/documentation/index.html.erb
index 725aa802..cb28f5ef 100644
--- a/documentation/index.html.erb
+++ b/documentation/index.html.erb
@@ -76,7 +76,7 @@
           <div id="repl_source_wrap"><textarea id="repl_source">reverse: (string) ->
   string.split('').reverse().join ''
 
-alert reverse '!tpircseeffoC'</textarea></div>
+alert reverse '.eeffoC yrT'</textarea></div>
           <pre id="repl_results"></pre>
           <button class="full_screen">go full screen</button>
           <button class="minimize">minimize</button>
@@ -90,8 +90,8 @@ alert reverse '!tpircseeffoC'</textarea></div>
         Annotated Source
       </div>
       <div class="contents">
-        <a href="documentation/docs/grammar.html">The Grammar &mdash; src/grammar</a>
-        <a href="documentation/docs/lexer.html">The Lexer &mdash; src/lexer</a>
+        <a href="documentation/docs/grammar.html">Grammar Rules &mdash; src/grammar</a>
+        <a href="documentation/docs/lexer.html">Lexing Tokens &mdash; src/lexer</a>
         <a href="documentation/docs/rewriter.html">The Rewriter &mdash; src/rewriter</a>
         <a href="documentation/docs/nodes.html">The Syntax Tree &mdash; src/nodes</a>
         <a href="documentation/docs/scope.html">Lexical Scope &mdash; src/scope</a>
diff --git a/index.html b/index.html
index 580f2f67..f3014190 100644
--- a/index.html
+++ b/index.html
@@ -62,7 +62,7 @@
           <div id="repl_source_wrap"><textarea id="repl_source">reverse: (string) ->
   string.split('').reverse().join ''
 
-alert reverse '!tpircseeffoC'</textarea></div>
+alert reverse '.eeffoC yrT'</textarea></div>
           <pre id="repl_results"></pre>
           <button class="full_screen">go full screen</button>
           <button class="minimize">minimize</button>
@@ -76,8 +76,8 @@ alert reverse '!tpircseeffoC'</textarea></div>
         Annotated Source
       </div>
       <div class="contents">
-        <a href="documentation/docs/grammar.html">The Grammar &mdash; src/grammar</a>
-        <a href="documentation/docs/lexer.html">The Lexer &mdash; src/lexer</a>
+        <a href="documentation/docs/grammar.html">Grammar Rules &mdash; src/grammar</a>
+        <a href="documentation/docs/lexer.html">Lexing Tokens &mdash; src/lexer</a>
         <a href="documentation/docs/rewriter.html">The Rewriter &mdash; src/rewriter</a>
         <a href="documentation/docs/nodes.html">The Syntax Tree &mdash; src/nodes</a>
         <a href="documentation/docs/scope.html">Lexical Scope &mdash; src/scope</a>

From f755580b1192974b0341b9c66fd80d0d3b27fe6b Mon Sep 17 00:00:00 2001
From: Chris Hoffman <cehoffman@gmail.com>
Date: Mon, 8 Mar 2010 08:18:37 -0600
Subject: [PATCH 05/10] Match regex highlighting to how coffee parses it

---
 extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage b/extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage
index 0a9729ee..1bbbeaf0 100644
--- a/extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage
+++ b/extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage
@@ -140,7 +140,7 @@
 		</dict>
 		<dict>
 			<key>begin</key>
-			<string>(?&lt;=[=(:]|^|return)\s*(/)(?![/*+{}?])</string>
+			<string>(?&lt;=[=(:\s]|^|return)\s*(/)(?![\s/*+{}?])</string>
 			<key>beginCaptures</key>
 			<dict>
 				<key>1</key>

From 81af8f296eb41665afc954d30602903f115d09e6 Mon Sep 17 00:00:00 2001
From: Stan Angeloff <insaned@abv.bg>
Date: Mon, 8 Mar 2010 20:05:02 +0200
Subject: [PATCH 06/10] Regular expression interpolations; fixed bug in string
 interpolations when all tokens were identifiers.

---
 lib/lexer.js                          | 108 ++++++++++++++++++--------
 lib/nodes.js                          |   8 +-
 src/lexer.coffee                      |  63 ++++++++++-----
 src/nodes.coffee                      |   2 +-
 test/test_regexp_interpolation.coffee |  17 ++++
 test/test_string_interpolation.coffee |   5 ++
 6 files changed, 146 insertions(+), 57 deletions(-)
 create mode 100644 test/test_regexp_interpolation.coffee

diff --git a/lib/lexer.js b/lib/lexer.js
index fab26120..1986ba76 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -1,5 +1,5 @@
 (function(){
-  var ACCESSORS, ASSIGNMENT, BEFORE_WHEN, CALLABLE, CODE, COFFEE_KEYWORDS, COMMENT, COMMENT_CLEANER, HEREDOC, HEREDOC_INDENT, IDENTIFIER, INTERPOLATION, JS_CLEANER, JS_FORBIDDEN, JS_KEYWORDS, KEYWORDS, LAST_DENT, LAST_DENTS, Lexer, MULTILINER, MULTI_DENT, NOT_REGEX, NO_NEWLINE, NUMBER, OPERATOR, REGEX, RESERVED, Rewriter, STRING_NEWLINES, WHITESPACE, compact, count, include, starts;
+  var ACCESSORS, ASSIGNMENT, BEFORE_WHEN, CALLABLE, CODE, COFFEE_KEYWORDS, COMMENT, COMMENT_CLEANER, HEREDOC, HEREDOC_INDENT, IDENTIFIER, INTERPOLATION, JS_CLEANER, JS_FORBIDDEN, JS_KEYWORDS, KEYWORDS, LAST_DENT, LAST_DENTS, Lexer, MULTILINER, MULTI_DENT, NOT_REGEX, NO_NEWLINE, NUMBER, OPERATOR, RESERVED, Rewriter, STRING_NEWLINES, WHITESPACE, compact, count, include, starts;
   // 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,
   // a token is produced, we consume the match, and start again. Tokens are in the
@@ -129,18 +129,18 @@
     // Matches strings, including multi-line strings. Ensures that quotation marks
     // are balanced within the string's contents, and within nested interpolations.
     Lexer.prototype.string_token = function string_token() {
-      var string;
+      var merge, string, supress;
       if (!(starts(this.chunk, '"') || starts(this.chunk, "'"))) {
         return false;
       }
-      string = this.balanced_token(['"', '"'], ['${', '}']);
+      string = this.balanced_token((supress = false), ['"', '"'], ['${', '}']);
       if (!(string)) {
-        string = this.balanced_token(["'", "'"]);
+        string = this.balanced_token((supress = false), ["'", "'"]);
       }
       if (!(string)) {
         return false;
       }
-      this.interpolate_string(string.replace(STRING_NEWLINES, " \\\n"));
+      this.interpolate_string(string.replace(STRING_NEWLINES, " \\\n"), (merge = true));
       this.line += count(string, "\n");
       this.i += string.length;
       return true;
@@ -160,11 +160,11 @@
     };
     // Matches JavaScript interpolated directly into the source via backticks.
     Lexer.prototype.js_token = function js_token() {
-      var script;
+      var script, supress;
       if (!(starts(this.chunk, '`'))) {
         return false;
       }
-      if (!((script = this.balanced_token(['`', '`'])))) {
+      if (!((script = this.balanced_token((supress = false), ['`', '`'])))) {
         return false;
       }
       this.token('JS', script.replace(JS_CLEANER, ''));
@@ -175,23 +175,57 @@
     // to distinguish from division, so we borrow some basic heuristics from
     // JavaScript and Ruby.
     Lexer.prototype.regex_token = function regex_token() {
-      var regex;
-      if (!((regex = this.match(REGEX, 1)))) {
+      var _a, _b, _c, _d, _e, each, flags, i, index, interp_tokens, merge, regex, str, supress;
+      if (!((regex = this.balanced_token((supress = true), ['/', '/'])))) {
+        return false;
+      }
+      if (regex.length < 3 || regex.match(/^\/\s+|\n/)) {
         return false;
       }
       if (include(NOT_REGEX, this.tag())) {
         return false;
       }
-      this.token('REGEX', regex);
+      flags = ['i', 'm', 'g', 'y'];
+      while (((index = flags.indexOf(this.chunk.substr(regex.length, 1)))) >= 0) {
+        regex += flags[index];
+        flags.splice(index, 1);
+      }
+      if (((0 < (_e = regex.indexOf('${'))) && (_e < regex.indexOf('}'))) || regex.match(/[^\\]\$[a-zA-Z_@]/)) {
+        _a = regex.substring(1).split('/');
+        str = _a[0];
+        flags = _a[1];
+        str = str.replace(/\\[^\$]/g, function(escaped) {
+          return '\\' + escaped;
+        });
+        this.tokens = this.tokens.concat([['(', '('], ['NEW', 'new'], ['IDENTIFIER', 'RegExp'], ['CALL_START', '(']]);
+        interp_tokens = this.interpolate_string("\"" + str + "\"", (merge = false));
+        _b = interp_tokens;
+        for (i = 0, _c = _b.length; i < _c; i++) {
+          each = _b[i];
+          if ((_d = each[0]) === 'TOKENS') {
+            this.tokens = this.tokens.concat(each[1]);
+          } else if (_d === 'STRING') {
+            this.token(each[0], each[1].substring(0, 1) + each[1].substring(1, each[1].length - 1).replace(/"/g, '\\"') + each[1].substring(0, 1));
+          } else {
+            this.token(each[0], each[1]);
+          }
+          if (i < interp_tokens.length - 1) {
+            this.token('+', '+');
+          }
+        }
+        this.tokens = this.tokens.concat([[',', ','], ['STRING', "'" + flags + "'"], [')', ')'], [')', ')']]);
+      } else {
+        this.token('REGEX', regex);
+      }
       this.i += regex.length;
       return true;
     };
     // Matches a token in which which the passed delimiter pairs must be correctly
     // balanced (ie. strings, JS literals).
-    Lexer.prototype.balanced_token = function balanced_token() {
+    Lexer.prototype.balanced_token = function balanced_token(supress) {
       var delimited;
-      delimited = Array.prototype.slice.call(arguments, 0);
-      return this.balanced_string.apply(this, [this.chunk].concat(delimited));
+      delimited = Array.prototype.slice.call(arguments, 1);
+      return this.balanced_string.apply(this, [this.chunk].concat([supress]).concat(delimited));
     };
     // Matches and conumes comments. We pass through comments into JavaScript,
     // so they're treated as real tokens, like any other part of the language.
@@ -395,9 +429,9 @@
     // a series of delimiters, all of which must be nested correctly within the
     // contents of the string. This method allows us to have strings within
     // interpolations within strings etc...
-    Lexer.prototype.balanced_string = function balanced_string(str) {
+    Lexer.prototype.balanced_string = function balanced_string(str, supress) {
       var _a, _b, _c, _d, close, delimited, i, levels, open, pair;
-      delimited = Array.prototype.slice.call(arguments, 1);
+      delimited = Array.prototype.slice.call(arguments, 2);
       levels = [];
       i = 0;
       while (i < str.length) {
@@ -429,7 +463,10 @@
         i += 1;
       }
       if (levels.length) {
-        throw new Error("SyntaxError: Unterminated " + (levels.pop()[0]) + " starting on line " + (this.line + 1));
+        if (!(supress)) {
+          throw new Error("SyntaxError: Unterminated " + (levels.pop()[0]) + " starting on line " + (this.line + 1));
+        }
+        return false;
       }
       if (i === 0) {
         return false;
@@ -444,8 +481,8 @@
     // If it encounters an interpolation, this method will recursively create a
     // new Lexer, tokenize the interpolated contents, and merge them into the
     // token stream.
-    Lexer.prototype.interpolate_string = function interpolate_string(str) {
-      var _a, _b, _c, _d, _e, each, expr, group, i, inner, interp, lexer, match, nested, pi, quote, tokens;
+    Lexer.prototype.interpolate_string = function interpolate_string(str, merge) {
+      var _a, _b, _c, _d, _e, _f, _g, each, expr, group, has_string, i, inner, interp, lexer, match, nested, pi, quote, supress, tokens;
       if (str.length < 3 || !starts(str, '"')) {
         return this.token('STRING', str);
       } else {
@@ -466,14 +503,14 @@
               interp = "this." + (interp.substring(1));
             }
             if (pi < i) {
-              tokens.push(['STRING', quote + (str.substring(pi, i)) + quote]);
+              tokens.push(['STRING', '' + quote + (str.substring(pi, i)) + quote]);
             }
             tokens.push(['IDENTIFIER', interp]);
             i += group.length - 1;
             pi = i + 1;
-          } else if (((expr = this.balanced_string(str.substring(i), ['${', '}'])))) {
+          } else if (((expr = this.balanced_string(str.substring(i), (supress = false), ['${', '}'])))) {
             if (pi < i) {
-              tokens.push(['STRING', quote + (str.substring(pi, i)) + quote]);
+              tokens.push(['STRING', '' + quote + (str.substring(pi, i)) + quote]);
             }
             inner = expr.substring(2, expr.length - 1);
             if (inner.length) {
@@ -484,7 +521,7 @@
               nested.pop();
               tokens.push(['TOKENS', nested]);
             } else {
-              tokens.push(['STRING', quote + quote]);
+              tokens.push(['STRING', '' + quote + quote]);
             }
             i += expr.length - 1;
             pi = i + 1;
@@ -492,19 +529,27 @@
           i += 1;
         }
         if (pi < i && pi < str.length - 1) {
-          tokens.push(['STRING', quote + (str.substring(pi, i)) + quote]);
+          tokens.push(['STRING', '' + quote + (str.substring(pi, i)) + quote]);
         }
-        _c = []; _d = tokens;
-        for (i = 0, _e = _d.length; i < _e; i++) {
-          each = _d[i];
-          _c.push((function() {
+        _c = tokens;
+        for (_d = 0, _e = _c.length; _d < _e; _d++) {
+          each = _c[_d];
+          each[0] === 'STRING' ? ((has_string = true)) : null;
+        }
+        if (!has_string) {
+          tokens.unshift(['STRING', "''"]);
+        }
+        if (((typeof merge !== "undefined" && merge !== null) ? merge : true)) {
+          _f = tokens;
+          for (i = 0, _g = _f.length; i < _g; i++) {
+            each = _f[i];
             each[0] === 'TOKENS' ? (this.tokens = this.tokens.concat(each[1])) : this.token(each[0], each[1]);
             if (i < tokens.length - 1) {
-              return this.token('+', '+');
+              this.token('+', '+');
             }
-          }).call(this));
+          }
         }
-        return _c;
+        return tokens;
       }
     };
     // Helpers
@@ -568,7 +613,7 @@
   // be used as identifiers or properties.
   JS_FORBIDDEN = JS_KEYWORDS.concat(RESERVED);
   // Token matching regexes.
-  IDENTIFIER = /^([a-zA-Z$_](\w|\$)*)/;
+  IDENTIFIER = /^([a-zA-Z\$_](\w|\$)*)/;
   NUMBER = /^(\b((0(x|X)[0-9a-fA-F]+)|([0-9]+(\.[0-9]+)?(e[+\-]?[0-9]+)?)))\b/i;
   HEREDOC = /^("{6}|'{6}|"{3}\n?([\s\S]*?)\n?([ \t]*)"{3}|'{3}\n?([\s\S]*?)\n?([ \t]*)'{3})/;
   INTERPOLATION = /^\$([a-zA-Z_@]\w*(\.\w+)*)/;
@@ -576,7 +621,6 @@
   WHITESPACE = /^([ \t]+)/;
   COMMENT = /^(((\n?[ \t]*)?#[^\n]*)+)/;
   CODE = /^((-|=)>)/;
-  REGEX = /^(\/(\S.*?)?([^\\]|\\\\)\/[imgy]{0,4})/;
   MULTI_DENT = /^((\n([ \t]*))+)(\.)?/;
   LAST_DENTS = /\n([ \t]*)/g;
   LAST_DENT = /\n([ \t]*)/;
diff --git a/lib/nodes.js b/lib/nodes.js
index 3ea376a6..bca3d9a8 100644
--- a/lib/nodes.js
+++ b/lib/nodes.js
@@ -289,7 +289,7 @@ idt += TAB
       var end, idt;
       idt = this.is_statement() ? this.idt() : '';
       end = this.is_statement() ? ';' : '';
-      return idt + this.value + end;
+      return '' + idt + this.value + end;
     };
     LiteralNode.prototype.toString = function toString(idt) {
       return " \"" + this.value + "\"";
@@ -762,7 +762,7 @@ idt += TAB
       props = props.empty() ? '' : props.compile(o) + '\n';
       extension = extension ? this.idt() + extension.compile(o) + ';\n' : '';
       returns = ret ? '\n' + this.idt() + 'return ' + this.variable.compile(o) + ';' : '';
-      return construct + extension + props + returns;
+      return '' + construct + extension + props + returns;
     };
     return ClassNode;
   }).call(this);
@@ -1540,7 +1540,7 @@ idt += TAB
         indent: this.idt(),
         chain_child: true
       })) : " else {\n" + (Expressions.wrap([this.else_body]).compile(o)) + "\n" + this.tab + "}";
-      return if_part + else_part;
+      return '' + if_part + else_part;
     };
     // Compile the IfNode as a ternary operator.
     IfNode.prototype.compile_ternary = function compile_ternary(o) {
@@ -1559,7 +1559,7 @@ idt += TAB
   // with Git.
   TRAILING_WHITESPACE = /\s+$/gm;
   // Keep this identifier regex in sync with the Lexer.
-  IDENTIFIER = /^[a-zA-Z$_](\w|\$)*$/;
+  IDENTIFIER = /^[a-zA-Z\$_](\w|\$)*$/;
   // Utility Functions
   // -----------------
   // Merge objects, returning a fresh copy with attributes from both sides.
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 30ba0d9b..b8822a51 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -96,10 +96,10 @@ exports.Lexer: class Lexer
   # are balanced within the string's contents, and within nested interpolations.
   string_token: ->
     return false unless starts(@chunk, '"') or starts(@chunk, "'")
-    string: @balanced_token ['"', '"'], ['${', '}']
-    string: @balanced_token ["'", "'"] unless string
+    string: @balanced_token supress: false, ['"', '"'], ['${', '}']
+    string: @balanced_token supress: false, ["'", "'"] unless string
     return false unless string
-    @interpolate_string string.replace STRING_NEWLINES, " \\\n"
+    @interpolate_string string.replace(STRING_NEWLINES, " \\\n"), merge: true
     @line += count string, "\n"
     @i += string.length
     true
@@ -117,7 +117,7 @@ exports.Lexer: class Lexer
   # Matches JavaScript interpolated directly into the source via backticks.
   js_token: ->
     return false unless starts @chunk, '`'
-    return false unless script: @balanced_token ['`', '`']
+    return false unless script: @balanced_token supress: false, ['`', '`']
     @token 'JS', script.replace(JS_CLEANER, '')
     @i += script.length
     true
@@ -126,16 +126,34 @@ exports.Lexer: class Lexer
   # to distinguish from division, so we borrow some basic heuristics from
   # JavaScript and Ruby.
   regex_token: ->
-    return false unless regex: @match REGEX, 1
+    return false unless regex: @balanced_token supress: true, ['/', '/']
+    return false if regex.length < 3 or regex.match /^\/\s+|\n/
     return false if include NOT_REGEX, @tag()
-    @token 'REGEX', regex
+    flags: ['i', 'm', 'g', 'y']
+    while (index: flags.indexOf @chunk.substr regex.length, 1) >= 0
+      regex += flags[index]
+      flags.splice index, 1
+    if (0 < regex.indexOf('${') < regex.indexOf('}')) or regex.match /[^\\]\$[a-zA-Z_@]/
+      [str, flags]: regex.substring(1).split('/')
+      str: str.replace /\\[^\$]/g, (escaped) -> '\\' + escaped
+      @tokens: @tokens.concat [['(', '('], ['NEW', 'new'], ['IDENTIFIER', 'RegExp'], ['CALL_START', '(']]
+      interp_tokens: @interpolate_string "\"$str\"", merge: false
+      for each, i in interp_tokens
+        switch each[0]
+          when 'TOKENS' then @tokens: @tokens.concat each[1]
+          when 'STRING' then @token each[0], each[1].substring(0, 1) + each[1].substring(1, each[1].length - 1).replace(/"/g, '\\"') + each[1].substring(0, 1)
+          else @token each[0], each[1]
+        @token '+', '+' if i < interp_tokens.length - 1
+      @tokens: @tokens.concat [[',', ','], ['STRING', "'$flags'"], [')', ')'], [')', ')']]
+    else
+      @token 'REGEX', regex
     @i += regex.length
     true
 
   # Matches a token in which which the passed delimiter pairs must be correctly
   # balanced (ie. strings, JS literals).
-  balanced_token: (delimited...) ->
-    @balanced_string @chunk, delimited...
+  balanced_token: (supress, delimited...) ->
+    @balanced_string @chunk, supress, delimited...
 
   # Matches and conumes comments. We pass through comments into JavaScript,
   # so they're treated as real tokens, like any other part of the language.
@@ -297,7 +315,7 @@ exports.Lexer: class Lexer
   # a series of delimiters, all of which must be nested correctly within the
   # contents of the string. This method allows us to have strings within
   # interpolations within strings etc...
-  balanced_string: (str, delimited...) ->
+  balanced_string: (str, supress, delimited...) ->
     levels: []
     i: 0
     while i < str.length
@@ -317,7 +335,9 @@ exports.Lexer: class Lexer
           break
       break unless levels.length
       i += 1
-    throw new Error "SyntaxError: Unterminated ${levels.pop()[0]} starting on line ${@line + 1}" if levels.length
+    if levels.length
+      throw new Error "SyntaxError: Unterminated ${levels.pop()[0]} starting on line ${@line + 1}" unless supress
+      return false
     return false if i is 0
     return str.substring(0, i)
 
@@ -331,7 +351,7 @@ exports.Lexer: class Lexer
   # If it encounters an interpolation, this method will recursively create a
   # new Lexer, tokenize the interpolated contents, and merge them into the
   # token stream.
-  interpolate_string: (str) ->
+  interpolate_string: (str, merge) ->
     if str.length < 3 or not starts str, '"'
       @token 'STRING', str
     else
@@ -349,7 +369,7 @@ exports.Lexer: class Lexer
           tokens.push ['IDENTIFIER', interp]
           i += group.length - 1
           pi: i + 1
-        else if (expr: @balanced_string str.substring(i), ['${', '}'])
+        else if (expr: @balanced_string str.substring(i), supress: false, ['${', '}'])
           tokens.push ['STRING', "$quote${ str.substring(pi, i) }$quote"] if pi < i
           inner: expr.substring(2, expr.length - 1)
           if inner.length
@@ -362,12 +382,16 @@ exports.Lexer: class Lexer
           pi: i + 1
         i += 1
       tokens.push ['STRING', "$quote${ str.substring(pi, i) }$quote"] if pi < i and pi < str.length - 1
-      for each, i in tokens
-        if each[0] is 'TOKENS'
-          @tokens: @tokens.concat each[1]
-        else
-          @token each[0], each[1]
-        @token '+', '+' if i < tokens.length - 1
+      (has_string: yes) for each in tokens when each[0] is 'STRING'
+      tokens.unshift ['STRING', "''"] if not has_string
+      if (merge ? true)
+        for each, i in tokens
+          if each[0] is 'TOKENS'
+            @tokens: @tokens.concat each[1]
+          else
+            @token each[0], each[1]
+          @token '+', '+' if i < tokens.length - 1
+      tokens
 
   # Helpers
   # -------
@@ -440,7 +464,7 @@ RESERVED: [
 JS_FORBIDDEN: JS_KEYWORDS.concat RESERVED
 
 # Token matching regexes.
-IDENTIFIER    : /^([a-zA-Z$_](\w|\$)*)/
+IDENTIFIER    : /^([a-zA-Z\$_](\w|\$)*)/
 NUMBER        : /^(\b((0(x|X)[0-9a-fA-F]+)|([0-9]+(\.[0-9]+)?(e[+\-]?[0-9]+)?)))\b/i
 HEREDOC       : /^("{6}|'{6}|"{3}\n?([\s\S]*?)\n?([ \t]*)"{3}|'{3}\n?([\s\S]*?)\n?([ \t]*)'{3})/
 INTERPOLATION : /^\$([a-zA-Z_@]\w*(\.\w+)*)/
@@ -448,7 +472,6 @@ OPERATOR      : /^([+\*&|\/\-%=<>:!?]+)/
 WHITESPACE    : /^([ \t]+)/
 COMMENT       : /^(((\n?[ \t]*)?#[^\n]*)+)/
 CODE          : /^((-|=)>)/
-REGEX         : /^(\/(\S.*?)?([^\\]|\\\\)\/[imgy]{0,4})/
 MULTI_DENT    : /^((\n([ \t]*))+)(\.)?/
 LAST_DENTS    : /\n([ \t]*)/g
 LAST_DENT     : /\n([ \t]*)/
diff --git a/src/nodes.coffee b/src/nodes.coffee
index 142928f3..bcd18331 100644
--- a/src/nodes.coffee
+++ b/src/nodes.coffee
@@ -1192,7 +1192,7 @@ TAB: '  '
 TRAILING_WHITESPACE: /\s+$/gm
 
 # Keep this identifier regex in sync with the Lexer.
-IDENTIFIER: /^[a-zA-Z$_](\w|\$)*$/
+IDENTIFIER: /^[a-zA-Z\$_](\w|\$)*$/
 
 # Utility Functions
 # -----------------
diff --git a/test/test_regexp_interpolation.coffee b/test/test_regexp_interpolation.coffee
new file mode 100644
index 00000000..c5b2c74b
--- /dev/null
+++ b/test/test_regexp_interpolation.coffee
@@ -0,0 +1,17 @@
+name: 'Bob'
+
+ok not not '"Bob"'.match(/^"${name}"$/i)
+ok '"Bobby"'.match(/^"${name}"$/i) is null
+
+ok not not 'Bob'.match(/^$name$/)
+ok 'Bobby'.match(/^$name/)
+
+ok 'Bobby'.match(/${"${"${"$name"}"}"}/imgy)
+
+ok '$a$b$c'.match(/\$A\$B\$C/i)
+
+a: 1
+b: 2
+c: 3
+
+ok '123'.match(/$a$b$c/i)
diff --git a/test/test_string_interpolation.coffee b/test/test_string_interpolation.coffee
index 5c454544..a69c2780 100644
--- a/test/test_string_interpolation.coffee
+++ b/test/test_string_interpolation.coffee
@@ -61,3 +61,8 @@ ok "Where is ${"the nested ${obj["name"]}"}?" is 'Where is the nested Joe?'
 ok "Hello ${world ? "$hello"}" is 'Hello World'
 
 ok "Hello ${"${"${obj["name"]}" + '!'}"}" is 'Hello Joe!'
+
+a: 1
+b: 2
+c: 3
+ok "$a$b$c" is '123'

From c04b43e047f42362e1023fd731e969886fb10cba Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Mon, 8 Mar 2010 19:27:38 -0500
Subject: [PATCH 07/10] adding documentation for var shadowing

---
 documentation/css/docs.css   | 1 +
 documentation/index.html.erb | 7 +++++++
 index.html                   | 9 ++++++++-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/documentation/css/docs.css b/documentation/css/docs.css
index d5e3d91b..1c74cfce 100644
--- a/documentation/css/docs.css
+++ b/documentation/css/docs.css
@@ -105,6 +105,7 @@ div.code {
   position: fixed;
   z-index: 100;
   height: 50px;
+  min-width: 490px;
   left: 40px; right: 40px; top: 25px;
   background: #ddd;
   padding-left: 235px;
diff --git a/documentation/index.html.erb b/documentation/index.html.erb
index cb28f5ef..8f610888 100644
--- a/documentation/index.html.erb
+++ b/documentation/index.html.erb
@@ -395,6 +395,13 @@ coffee --print app/scripts/*.coffee > concatenation.js</pre>
       should not be able to change the value of the external variable of the same name, and
       therefore has a declaration of its own.
     </p>
+    <p>
+      This behavior is effectively identical to Ruby's scope for local variables.
+      Because you don't have direct access to the <tt>var</tt> keyword, 
+      it's impossible to shadow an outer variable on purpose, you may only refer 
+      to it. So be careful that you're not reusing the name of an external 
+      variable accidentally, if you're writing a deeply nested function.
+    </p>
     <p>
       Although suppressed within this documentation for clarity, all
       CoffeeScript output is wrapped in an anonymous function:
diff --git a/index.html b/index.html
index f3014190..a315faa2 100644
--- a/index.html
+++ b/index.html
@@ -566,6 +566,13 @@ new_num = change_numbers();
       should not be able to change the value of the external variable of the same name, and
       therefore has a declaration of its own.
     </p>
+    <p>
+      This behavior is effectively identical to Ruby's scope for local variables.
+      Because you don't have direct access to the <tt>var</tt> keyword, 
+      it's impossible to shadow an outer variable on purpose, you may only refer 
+      to it. So be careful that you're not reusing the name of an external 
+      variable accidentally, if you're writing a deeply nested function.
+    </p>
     <p>
       Although suppressed within this documentation for clarity, all
       CoffeeScript output is wrapped in an anonymous function:
@@ -995,7 +1002,7 @@ numbers_copy = numbers.slice(0, numbers.length);
     </p>
     <div class='code'><pre class="idle">numbers<span class="Keyword">:</span> [<span class="Number">0</span>, <span class="Number">1</span>, <span class="Number">2</span>, <span class="Number">3</span>, <span class="Number">4</span>, <span class="Number">5</span>, <span class="Number">6</span>, <span class="Number">7</span>, <span class="Number">8</span>, <span class="Number">9</span>]
 
-numbers<span class="Keyword">[</span><span class="Number">3</span>..<span class="Number">6</span><span class="Keyword">]:</span> [<span class="Keyword">-</span><span class="Number">3</span>, <span class="Keyword">-</span><span class="Number">4</span>, <span class="Keyword">-</span><span class="Number">5</span>, <span class="Keyword">-</span><span class="Number">6</span>]
+numbers[<span class="Number">3</span>..<span class="Number">6</span>]<span class="Keyword">:</span> [<span class="Keyword">-</span><span class="Number">3</span>, <span class="Keyword">-</span><span class="Number">4</span>, <span class="Keyword">-</span><span class="Number">5</span>, <span class="Keyword">-</span><span class="Number">6</span>]
 
 
 </pre><pre class="idle"><span class="Storage">var</span> numbers;

From 121f01c06fb0268e53c42e79f230cdef574b4b0c Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Mon, 8 Mar 2010 19:43:12 -0500
Subject: [PATCH 08/10] merged stan's interpolation_3, a couple of tweaks

---
 lib/lexer.js        | 5 ++++-
 lib/rewriter.js     | 2 +-
 src/lexer.coffee    | 3 ++-
 src/rewriter.coffee | 2 +-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/lexer.js b/lib/lexer.js
index 1986ba76..988fb32e 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -33,7 +33,7 @@
     Lexer.prototype.tokenize = function tokenize(code, options) {
       var o;
       o = options || {};
-      this.code = code;
+      this.code = code || '';
       // The remainder of the source code.
       this.i = 0;
       // Current character position we're parsing.
@@ -176,6 +176,9 @@
     // JavaScript and Ruby.
     Lexer.prototype.regex_token = function regex_token() {
       var _a, _b, _c, _d, _e, each, flags, i, index, interp_tokens, merge, regex, str, supress;
+      if (!(starts(this.chunk, '/'))) {
+        return false;
+      }
       if (!((regex = this.balanced_token((supress = true), ['/', '/'])))) {
         return false;
       }
diff --git a/lib/rewriter.js b/lib/rewriter.js
index cbf63c26..e09299c4 100644
--- a/lib/rewriter.js
+++ b/lib/rewriter.js
@@ -81,7 +81,7 @@
     Rewriter.prototype.remove_leading_newlines = function remove_leading_newlines() {
       var _a;
       _a = [];
-      while (this.tokens[0][0] === 'TERMINATOR') {
+      while (this.tokens[0] && this.tokens[0][0] === 'TERMINATOR') {
         _a.push(this.tokens.shift());
       }
       return _a;
diff --git a/src/lexer.coffee b/src/lexer.coffee
index b8822a51..6f5e4024 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -36,7 +36,7 @@ exports.Lexer: class Lexer
   # unless explicitly asked not to.
   tokenize: (code, options) ->
     o        : options or {}
-    @code    : code         # The remainder of the source code.
+    @code    : code or ''   # The remainder of the source code.
     @i       : 0            # Current character position we're parsing.
     @line    : o.line or 0  # The current line.
     @indent  : 0            # The current indentation level.
@@ -126,6 +126,7 @@ exports.Lexer: class Lexer
   # to distinguish from division, so we borrow some basic heuristics from
   # JavaScript and Ruby.
   regex_token: ->
+    return false unless starts @chunk, '/'
     return false unless regex: @balanced_token supress: true, ['/', '/']
     return false if regex.length < 3 or regex.match /^\/\s+|\n/
     return false if include NOT_REGEX, @tag()
diff --git a/src/rewriter.coffee b/src/rewriter.coffee
index 1fe3a8d8..8848f6db 100644
--- a/src/rewriter.coffee
+++ b/src/rewriter.coffee
@@ -62,7 +62,7 @@ exports.Rewriter: class Rewriter
   # Leading newlines would introduce an ambiguity in the grammar, so we
   # dispatch them here.
   remove_leading_newlines: ->
-    @tokens.shift() while @tokens[0][0] is 'TERMINATOR'
+    @tokens.shift() while @tokens[0] and @tokens[0][0] is 'TERMINATOR'
 
   # Some blocks occur in the middle of expressions -- when we're expecting
   # this, remove their trailing newlines.

From 3291bd2a4af700e8c3508a43a64c576b433a73b9 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Mon, 8 Mar 2010 20:07:19 -0500
Subject: [PATCH 09/10] removing the 'supress' option from the lexer, just look
 at the slash.

---
 Cakefile                                      |  2 +-
 .../Syntaxes/CoffeeScript.tmLanguage          |  2 +-
 lib/lexer.js                                  | 32 ++++++++-----------
 src/lexer.coffee                              | 20 ++++++------
 4 files changed, 26 insertions(+), 30 deletions(-)

diff --git a/Cakefile b/Cakefile
index 46a0df74..dc436688 100644
--- a/Cakefile
+++ b/Cakefile
@@ -29,7 +29,7 @@ task 'build', 'build the CoffeeScript language from source', ->
 
 
 task 'build:full', 'checkout /lib, rebuild the source twice, and run the tests', ->
-  exec 'git co lib && bin/cake build && bin/cake build && bin/cake test', (err, stdout, stderr) ->
+  exec 'git checkout lib && bin/cake build && bin/cake build && bin/cake test', (err, stdout, stderr) ->
     print stdout if stdout
     print stderr if stderr
     throw err    if err
diff --git a/extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage b/extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage
index 1bbbeaf0..16a325bb 100644
--- a/extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage
+++ b/extras/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage
@@ -150,7 +150,7 @@
 				</dict>
 			</dict>
 			<key>end</key>
-			<string>(/)[igm]*</string>
+			<string>(/)[igmy]*</string>
 			<key>endCaptures</key>
 			<dict>
 				<key>1</key>
diff --git a/lib/lexer.js b/lib/lexer.js
index 988fb32e..bef8b616 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -129,15 +129,11 @@
     // Matches strings, including multi-line strings. Ensures that quotation marks
     // are balanced within the string's contents, and within nested interpolations.
     Lexer.prototype.string_token = function string_token() {
-      var merge, string, supress;
+      var merge, string;
       if (!(starts(this.chunk, '"') || starts(this.chunk, "'"))) {
         return false;
       }
-      string = this.balanced_token((supress = false), ['"', '"'], ['${', '}']);
-      if (!(string)) {
-        string = this.balanced_token((supress = false), ["'", "'"]);
-      }
-      if (!(string)) {
+      if (!((string = this.balanced_token(['"', '"'], ['${', '}']) || this.balanced_token(["'", "'"])))) {
         return false;
       }
       this.interpolate_string(string.replace(STRING_NEWLINES, " \\\n"), (merge = true));
@@ -160,11 +156,11 @@
     };
     // Matches JavaScript interpolated directly into the source via backticks.
     Lexer.prototype.js_token = function js_token() {
-      var script, supress;
+      var script;
       if (!(starts(this.chunk, '`'))) {
         return false;
       }
-      if (!((script = this.balanced_token((supress = false), ['`', '`'])))) {
+      if (!((script = this.balanced_token(['`', '`'])))) {
         return false;
       }
       this.token('JS', script.replace(JS_CLEANER, ''));
@@ -175,11 +171,11 @@
     // to distinguish from division, so we borrow some basic heuristics from
     // JavaScript and Ruby.
     Lexer.prototype.regex_token = function regex_token() {
-      var _a, _b, _c, _d, _e, each, flags, i, index, interp_tokens, merge, regex, str, supress;
+      var _a, _b, _c, _d, _e, each, flags, i, index, interp_tokens, merge, regex, str;
       if (!(starts(this.chunk, '/'))) {
         return false;
       }
-      if (!((regex = this.balanced_token((supress = true), ['/', '/'])))) {
+      if (!((regex = this.balanced_token(['/', '/'])))) {
         return false;
       }
       if (regex.length < 3 || regex.match(/^\/\s+|\n/)) {
@@ -225,10 +221,10 @@
     };
     // Matches a token in which which the passed delimiter pairs must be correctly
     // balanced (ie. strings, JS literals).
-    Lexer.prototype.balanced_token = function balanced_token(supress) {
+    Lexer.prototype.balanced_token = function balanced_token() {
       var delimited;
-      delimited = Array.prototype.slice.call(arguments, 1);
-      return this.balanced_string.apply(this, [this.chunk].concat([supress]).concat(delimited));
+      delimited = Array.prototype.slice.call(arguments, 0);
+      return this.balanced_string.apply(this, [this.chunk].concat(delimited));
     };
     // Matches and conumes comments. We pass through comments into JavaScript,
     // so they're treated as real tokens, like any other part of the language.
@@ -432,9 +428,9 @@
     // a series of delimiters, all of which must be nested correctly within the
     // contents of the string. This method allows us to have strings within
     // interpolations within strings etc...
-    Lexer.prototype.balanced_string = function balanced_string(str, supress) {
+    Lexer.prototype.balanced_string = function balanced_string(str) {
       var _a, _b, _c, _d, close, delimited, i, levels, open, pair;
-      delimited = Array.prototype.slice.call(arguments, 2);
+      delimited = Array.prototype.slice.call(arguments, 1);
       levels = [];
       i = 0;
       while (i < str.length) {
@@ -466,7 +462,7 @@
         i += 1;
       }
       if (levels.length) {
-        if (!(supress)) {
+        if (!(delimited[0][0] === '/')) {
           throw new Error("SyntaxError: Unterminated " + (levels.pop()[0]) + " starting on line " + (this.line + 1));
         }
         return false;
@@ -485,7 +481,7 @@
     // new Lexer, tokenize the interpolated contents, and merge them into the
     // token stream.
     Lexer.prototype.interpolate_string = function interpolate_string(str, merge) {
-      var _a, _b, _c, _d, _e, _f, _g, each, expr, group, has_string, i, inner, interp, lexer, match, nested, pi, quote, supress, tokens;
+      var _a, _b, _c, _d, _e, _f, _g, each, expr, group, has_string, i, inner, interp, lexer, match, nested, pi, quote, tokens;
       if (str.length < 3 || !starts(str, '"')) {
         return this.token('STRING', str);
       } else {
@@ -511,7 +507,7 @@
             tokens.push(['IDENTIFIER', interp]);
             i += group.length - 1;
             pi = i + 1;
-          } else if (((expr = this.balanced_string(str.substring(i), (supress = false), ['${', '}'])))) {
+          } else if (((expr = this.balanced_string(str.substring(i), ['${', '}'])))) {
             if (pi < i) {
               tokens.push(['STRING', '' + quote + (str.substring(pi, i)) + quote]);
             }
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 6f5e4024..27957c85 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -96,9 +96,9 @@ exports.Lexer: class Lexer
   # are balanced within the string's contents, and within nested interpolations.
   string_token: ->
     return false unless starts(@chunk, '"') or starts(@chunk, "'")
-    string: @balanced_token supress: false, ['"', '"'], ['${', '}']
-    string: @balanced_token supress: false, ["'", "'"] unless string
-    return false unless string
+    return false unless string:
+      @balanced_token(['"', '"'], ['${', '}']) or
+      @balanced_token ["'", "'"]
     @interpolate_string string.replace(STRING_NEWLINES, " \\\n"), merge: true
     @line += count string, "\n"
     @i += string.length
@@ -117,7 +117,7 @@ exports.Lexer: class Lexer
   # Matches JavaScript interpolated directly into the source via backticks.
   js_token: ->
     return false unless starts @chunk, '`'
-    return false unless script: @balanced_token supress: false, ['`', '`']
+    return false unless script: @balanced_token ['`', '`']
     @token 'JS', script.replace(JS_CLEANER, '')
     @i += script.length
     true
@@ -127,7 +127,7 @@ exports.Lexer: class Lexer
   # JavaScript and Ruby.
   regex_token: ->
     return false unless starts @chunk, '/'
-    return false unless regex: @balanced_token supress: true, ['/', '/']
+    return false unless regex: @balanced_token ['/', '/']
     return false if regex.length < 3 or regex.match /^\/\s+|\n/
     return false if include NOT_REGEX, @tag()
     flags: ['i', 'm', 'g', 'y']
@@ -153,8 +153,8 @@ exports.Lexer: class Lexer
 
   # Matches a token in which which the passed delimiter pairs must be correctly
   # balanced (ie. strings, JS literals).
-  balanced_token: (supress, delimited...) ->
-    @balanced_string @chunk, supress, delimited...
+  balanced_token: (delimited...) ->
+    @balanced_string @chunk, delimited...
 
   # Matches and conumes comments. We pass through comments into JavaScript,
   # so they're treated as real tokens, like any other part of the language.
@@ -316,7 +316,7 @@ exports.Lexer: class Lexer
   # a series of delimiters, all of which must be nested correctly within the
   # contents of the string. This method allows us to have strings within
   # interpolations within strings etc...
-  balanced_string: (str, supress, delimited...) ->
+  balanced_string: (str, delimited...) ->
     levels: []
     i: 0
     while i < str.length
@@ -337,7 +337,7 @@ exports.Lexer: class Lexer
       break unless levels.length
       i += 1
     if levels.length
-      throw new Error "SyntaxError: Unterminated ${levels.pop()[0]} starting on line ${@line + 1}" unless supress
+      throw new Error "SyntaxError: Unterminated ${levels.pop()[0]} starting on line ${@line + 1}" unless delimited[0][0] is '/'
       return false
     return false if i is 0
     return str.substring(0, i)
@@ -370,7 +370,7 @@ exports.Lexer: class Lexer
           tokens.push ['IDENTIFIER', interp]
           i += group.length - 1
           pi: i + 1
-        else if (expr: @balanced_string str.substring(i), supress: false, ['${', '}'])
+        else if (expr: @balanced_string str.substring(i), ['${', '}'])
           tokens.push ['STRING', "$quote${ str.substring(pi, i) }$quote"] if pi < i
           inner: expr.substring(2, expr.length - 1)
           if inner.length

From 3396dce2bbbe2dbd2eb29cc257279997b2dd83a9 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Mon, 8 Mar 2010 20:57:28 -0500
Subject: [PATCH 10/10] waypoint -- going to try to clean up regex_token

---
 Cakefile         |  4 ++--
 lib/lexer.js     | 14 +++++++-------
 src/lexer.coffee |  8 ++++----
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/Cakefile b/Cakefile
index dc436688..1bd9240e 100644
--- a/Cakefile
+++ b/Cakefile
@@ -28,8 +28,8 @@ task 'build', 'build the CoffeeScript language from source', ->
   run ['-c', '-o', 'lib'].concat(files)
 
 
-task 'build:full', 'checkout /lib, rebuild the source twice, and run the tests', ->
-  exec 'git checkout lib && bin/cake build && bin/cake build && bin/cake test', (err, stdout, stderr) ->
+task 'build:full', 'rebuild the source twice, and run the tests', ->
+  exec 'bin/cake build && bin/cake build && bin/cake test', (err, stdout, stderr) ->
     print stdout if stdout
     print stderr if stderr
     throw err    if err
diff --git a/lib/lexer.js b/lib/lexer.js
index bef8b616..ee349cce 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -175,13 +175,13 @@
       if (!(starts(this.chunk, '/'))) {
         return false;
       }
+      if (include(NOT_REGEX, this.tag())) {
+        return false;
+      }
       if (!((regex = this.balanced_token(['/', '/'])))) {
         return false;
       }
-      if (regex.length < 3 || regex.match(/^\/\s+|\n/)) {
-        return false;
-      }
-      if (include(NOT_REGEX, this.tag())) {
+      if (regex.length < 3 || regex.match(/^\/\s+/m)) {
         return false;
       }
       flags = ['i', 'm', 'g', 'y'];
@@ -462,10 +462,10 @@
         i += 1;
       }
       if (levels.length) {
-        if (!(delimited[0][0] === '/')) {
-          throw new Error("SyntaxError: Unterminated " + (levels.pop()[0]) + " starting on line " + (this.line + 1));
+        if (delimited[0][0] === '/') {
+          return false;
         }
-        return false;
+        throw new Error("SyntaxError: Unterminated " + (levels.pop()[0]) + " starting on line " + (this.line + 1));
       }
       if (i === 0) {
         return false;
diff --git a/src/lexer.coffee b/src/lexer.coffee
index 27957c85..9e71baf3 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -127,9 +127,9 @@ exports.Lexer: class Lexer
   # JavaScript and Ruby.
   regex_token: ->
     return false unless starts @chunk, '/'
-    return false unless regex: @balanced_token ['/', '/']
-    return false if regex.length < 3 or regex.match /^\/\s+|\n/
     return false if include NOT_REGEX, @tag()
+    return false unless regex: @balanced_token ['/', '/']
+    return false if regex.length < 3 or regex.match /^\/\s+/m
     flags: ['i', 'm', 'g', 'y']
     while (index: flags.indexOf @chunk.substr regex.length, 1) >= 0
       regex += flags[index]
@@ -337,8 +337,8 @@ exports.Lexer: class Lexer
       break unless levels.length
       i += 1
     if levels.length
-      throw new Error "SyntaxError: Unterminated ${levels.pop()[0]} starting on line ${@line + 1}" unless delimited[0][0] is '/'
-      return false
+      return false if delimited[0][0] is '/'
+      throw new Error "SyntaxError: Unterminated ${levels.pop()[0]} starting on line ${@line + 1}"
     return false if i is 0
     return str.substring(0, i)