allowing keywords as identifiers, when used as identifiers, because we've got more keywords than JavaScript does.

lib/coffee_script/lexer.js

@@ -1,5 +1,5 @@
 (function(){
-  var ASSIGNMENT, BEFORE_WHEN, CALLABLE, CODE, COMMENT, COMMENT_CLEANER, HEREDOC, HEREDOC_INDENT, IDENTIFIER, JS, JS_CLEANER, KEYWORDS, LAST_DENT, LAST_DENTS, MULTILINER, MULTI_DENT, NOT_REGEX, NO_NEWLINE, NUMBER, OPERATOR, REGEX, Rewriter, STRING, STRING_NEWLINES, WHITESPACE, lex;
+  var ACCESSORS, ASSIGNMENT, BEFORE_WHEN, CALLABLE, CODE, COMMENT, COMMENT_CLEANER, HEREDOC, HEREDOC_INDENT, IDENTIFIER, JS, JS_CLEANER, KEYWORDS, LAST_DENT, LAST_DENTS, MULTILINER, MULTI_DENT, NOT_REGEX, NO_NEWLINE, NUMBER, OPERATOR, REGEX, Rewriter, STRING, STRING_NEWLINES, WHITESPACE, lex;
   if ((typeof process !== "undefined" && process !== null)) {
     Rewriter = require('./rewriter').Rewriter;
   } else {
@@ -41,6 +41,9 @@
   NOT_REGEX = ['IDENTIFIER', 'NUMBER', 'REGEX', 'STRING', ')', '++', '--', ']', '}', 'FALSE', 'NULL', 'TRUE'];
   // Tokens which could legitimately be invoked or indexed.
   CALLABLE = ['IDENTIFIER', 'SUPER', ')', ']', '}', 'STRING'];
+  // Tokens that indicate an access -- keywords immediately following will be
+  // treated as identifiers.
+  ACCESSORS = ['PROPERTY_ACCESS', 'PROTOTYPE_ACCESS', 'SOAK_ACCESS', '@'];
   // Tokens that, when immediately preceding a 'WHEN', indicate that its leading.
   BEFORE_WHEN = ['INDENT', 'OUTDENT', 'TERMINATOR'];
   // Scan by attempting to match tokens one character at a time. Slow and steady.
@@ -57,8 +60,6 @@
     // The stack of all indent levels we are currently within.
     this.tokens = [];
     // Collection of all parsed tokens in the form [:TOKEN_TYPE, value]
-    this.spaced = null;
-    // The last token that has a space following it.
     while (this.i < this.code.length) {
       this.chunk = this.code.slice(this.i);
       this.extract_next_token();
@@ -105,16 +106,10 @@
     if (!((id = this.match(IDENTIFIER, 1)))) {
       return false;
     }
-    // Keywords are special identifiers tagged with their own name,
+    if (this.value() === '::') {
-    // 'if' will result in an ['IF', "if"] token.
-    tag = KEYWORDS.indexOf(id) >= 0 ? id.toUpperCase() : 'IDENTIFIER';
-    if (tag === 'WHEN' && BEFORE_WHEN.indexOf(this.tag()) >= 0) {
-      tag = 'LEADING_WHEN';
-    }
-    if (tag === 'IDENTIFIER' && this.value() === '::') {
       this.tag(1, 'PROTOTYPE_ACCESS');
     }
-    if (tag === 'IDENTIFIER' && this.value() === '.' && !(this.value(2) === '.')) {
+    if (this.value() === '.' && !(this.value(2) === '.')) {
       if (this.tag(2) === '?') {
         this.tag(1, 'SOAK_ACCESS');
         this.tokens.splice(-2, 1);
@@ -122,6 +117,13 @@
         this.tag(1, 'PROPERTY_ACCESS');
       }
     }
+    tag = 'IDENTIFIER';
+    if (KEYWORDS.indexOf(id) >= 0 && !(ACCESSORS.indexOf(this.tag()) >= 0)) {
+      tag = id.toUpperCase();
+    }
+    if (tag === 'WHEN' && BEFORE_WHEN.indexOf(this.tag()) >= 0) {
+      tag = 'LEADING_WHEN';
+    }
     this.token(tag, id);
     this.i += id.length;
     return true;
@@ -245,7 +247,7 @@
     if (!((space = this.match(WHITESPACE, 1)))) {
       return false;
     }
-    this.spaced = this.value();
+    this.tokens[this.tokens.length - 1].spaced = true;
     this.i += space.length;
     return true;
   };
@@ -279,7 +281,7 @@
     if (value === ';') {
       tag = 'TERMINATOR';
     }
-    if (this.value() !== this.spaced && CALLABLE.indexOf(this.tag()) >= 0) {
+    if (!this.tokens[this.tokens.length - 1].spaced && CALLABLE.indexOf(this.tag()) >= 0) {
       if (value === '(') {
         tag = 'CALL_START';
       }

src/lexer.coffee

@@ -61,6 +61,10 @@ NOT_REGEX: [
 # Tokens which could legitimately be invoked or indexed.
 CALLABLE: ['IDENTIFIER', 'SUPER', ')', ']', '}', 'STRING']
 
+# Tokens that indicate an access -- keywords immediately following will be
+# treated as identifiers.
+ACCESSORS: ['PROPERTY_ACCESS', 'PROTOTYPE_ACCESS', 'SOAK_ACCESS', '@']
+
 # Tokens that, when immediately preceding a 'WHEN', indicate that its leading.
 BEFORE_WHEN: ['INDENT', 'OUTDENT', 'TERMINATOR']
 
@@ -72,7 +76,6 @@ lex::tokenize: (code) ->
   @indent  : 0          # The current indent level.
   @indents : []         # The stack of all indent levels we are currently within.
   @tokens  : []         # Collection of all parsed tokens in the form [:TOKEN_TYPE, value]
-  @spaced  : null       # The last token that has a space following it.
   while @i < @code.length
     @chunk: @code.slice(@i)
     @extract_next_token()
@@ -98,17 +101,16 @@ lex::extract_next_token: ->
 # Matches identifying literals: variables, keywords, method names, etc.
 lex::identifier_token: ->
   return false unless id: @match IDENTIFIER, 1
-  # Keywords are special identifiers tagged with their own name,
+  @tag(1, 'PROTOTYPE_ACCESS') if @value() is '::'
-  # 'if' will result in an ['IF', "if"] token.
+  if @value() is '.' and not (@value(2) is '.')
-  tag: if KEYWORDS.indexOf(id) >= 0 then id.toUpperCase() else 'IDENTIFIER'
-  tag: 'LEADING_WHEN' if tag is 'WHEN' and BEFORE_WHEN.indexOf(@tag()) >= 0
-  @tag(1, 'PROTOTYPE_ACCESS') if tag is 'IDENTIFIER' and @value() is '::'
-  if tag is 'IDENTIFIER' and @value() is '.' and !(@value(2) is '.')
     if @tag(2) is '?'
       @tag(1, 'SOAK_ACCESS')
       @tokens.splice(-2, 1)
     else
       @tag(1, 'PROPERTY_ACCESS')
+  tag: 'IDENTIFIER'
+  tag:  id.toUpperCase() if KEYWORDS.indexOf(id) >= 0 and not (ACCESSORS.indexOf(@tag()) >= 0)
+  tag: 'LEADING_WHEN' if tag is 'WHEN' and BEFORE_WHEN.indexOf(@tag()) >= 0
   @token(tag, id)
   @i += id.length
   true
@@ -199,7 +201,7 @@ lex::outdent_token: (move_out) ->
 # Matches and consumes non-meaningful whitespace.
 lex::whitespace_token: ->
   return false unless space: @match WHITESPACE, 1
-  @spaced: @value()
+  @tokens[@tokens.length - 1].spaced: true
   @i += space.length
   true
 
@@ -224,7 +226,8 @@ lex::literal_token: ->
   value ||= @chunk.substr(0, 1)
   tag: if value.match(ASSIGNMENT) then 'ASSIGN' else value
   tag: 'TERMINATOR' if value == ';'
-  if @value() isnt @spaced and CALLABLE.indexOf(@tag()) >= 0
+
+  if not @tokens[@tokens.length - 1].spaced and CALLABLE.indexOf(@tag()) >= 0
     tag: 'CALL_START'  if value is '('
     tag: 'INDEX_START' if value is '['
   @token tag, value

test/fixtures/execution/test_literals.coffee

@@ -51,3 +51,12 @@ bob: {
 
 puts bob.hello() is "Hello Bob"
 puts bob[10] is 'number'
+
+
+obj: {
+  'is':  -> yes
+  'not': -> no
+}
+
+puts obj.is()
+puts not obj.not()