documentation waypoint

lib/coffee_script/CoffeeScript.tmbundle/Syntaxes/CoffeeScript.tmLanguage

@@ -229,7 +229,7 @@
 		</dict>
 		<dict>
 			<key>match</key>
-			<string>\b(super|this)\b</string>
+			<string>\b(super|this|extends)\b</string>
 			<key>name</key>
 			<string>variable.language.cs</string>
 		</dict>

lib/coffee_script/grammar.y

@@ -10,7 +10,7 @@ token TRY CATCH FINALLY THROW
 token BREAK CONTINUE
 token FOR IN WHILE
 token SWITCH CASE
-token SUPER
+token EXTENDS SUPER
 token DELETE
 token NEWLINE
 token JS
@@ -28,8 +28,8 @@ prechigh
   right    '-=' '+=' '/=' '*=' '||=' '&&='
   right    DELETE
   left     "."
-  right    THROW FOR IN WHILE
-  left     UNLESS IF ELSE
+  right    THROW FOR IN WHILE NEW
+  left     UNLESS IF ELSE EXTENDS
   left     ":"
   right    RETURN
 preclow
@@ -68,6 +68,7 @@ rule
   | Call
   | Code
   | Operation
+  | Extend
   ;
 
   # We have to take extra care to convert these statements into expressions.
@@ -246,6 +247,11 @@ rule
     SUPER "(" ArgList ")"             { result = CallNode.new(:super, val[2]) }
   ;
 
+  # Extending a class.
+  Extend:
+    IDENTIFIER EXTENDS Expression     { result = ExtendNode.new(val[0], val[2]) }
+  ;
+
   # The array literal.
   Array:
     "[" ArgList "]"                   { result = ArrayNode.new(val[1]) }

lib/coffee_script/lexer.rb

@@ -14,7 +14,7 @@ module CoffeeScript
                   "break", "continue",
                   "for", "in", "while",
                   "switch", "case",
-                  "super",
+                  "extends", "super",
                   "delete"]
 
     # Token matching regexes.

lib/coffee_script/nodes.rb

@@ -110,6 +110,10 @@ module CoffeeScript
       STATEMENTS.include?(@value.to_s)
     end
 
+    def line_ending
+      @value.to_s[-1..-1] == ';' ? '' : ';'
+    end
+
     def compile(indent, scope, opts={})
       code = @value.to_s
       write(code)
@@ -171,6 +175,20 @@ module CoffeeScript
     end
   end
 
+  class ExtendNode < Node
+
+    attr_reader :subclass, :superclass
+
+    def initialize(subclass, superclass)
+      @subclass, @superclass = subclass, superclass
+    end
+
+    def compile(indent, scope, opts={})
+      "#{@subclass}.prototype = #{@superclass.compile(indent, scope, opts)}"
+    end
+
+  end
+
   # A value, indexed or dotted into, or vanilla.
   class ValueNode < Node
     attr_reader :literal, :properties, :last
@@ -269,7 +287,7 @@ module CoffeeScript
 
     def compile(indent, scope, opts={})
       name      = @variable.respond_to?(:compile) ? @variable.compile(indent, scope) : @variable
-      last      = @variable.respond_to?(:last) ? @variable.last : name
+      last      = @variable.respond_to?(:last) ? @variable.last.to_s : name.to_s
       opts      = opts.merge({:assign => name, :last_assign => last})
       return write("#{@variable}: #{@value.compile(indent, scope, opts)}") if @context == :object
       return write("#{name} = #{@value.compile(indent, scope, opts)}") if @variable.properties?