adding splats as arguments to function calls

lib/coffee_script/grammar.y

@@ -5,7 +5,7 @@ token IF ELSE UNLESS
 token NUMBER STRING REGEX
 token TRUE FALSE YES NO ON OFF
 token IDENTIFIER PROPERTY_ACCESS
-token CODE PARAM SPLAT NEW RETURN
+token CODE PARAM NEW RETURN
 token TRY CATCH FINALLY THROW
 token BREAK CONTINUE
 token FOR IN WHILE
@@ -19,7 +19,7 @@ token INDENT OUTDENT
 
 # Declare order of operations.
 prechigh
-  nonassoc UMINUS NOT '!' '!!' '~' '++' '--'
+  nonassoc UMINUS SPLAT NOT '!' '!!' '~' '++' '--'
   left     '*' '/' '%'
   left     '+' '-'
   left     '<<' '>>' '>>>'
@@ -70,6 +70,7 @@ rule
   | For
   | Switch
   | Extends
+  | Splat
   | Comment
   ;
 
@@ -193,7 +194,11 @@ rule
 
   Param:
     PARAM
-  | SPLAT                             { result = SplatNode.new(val[0]) }
+  | '*' PARAM = SPLAT                 { result = ParamSplatNode.new(val[1]) }
+  ;
+
+  Splat:
+    '*' Value = SPLAT                 { result = ArgSplatNode.new(val[1]) }
   ;
 
   # Expressions that can be treated as values.

lib/coffee_script/lexer.rb

@@ -196,17 +196,11 @@ module CoffeeScript
       i = 0
       loop do
         i -= 1
-        tok, prev = @tokens[i], @tokens[i - 1]
+        tok = @tokens[i]
         return if !tok
-        next if tok[0] == ','
+        next if ['*', ','].include?(tok[0])
         return if tok[0] != :IDENTIFIER
-        if prev && prev[0] == '*'
-          tok[0] = :SPLAT
-          @tokens.delete_at(i - 1)
-          i -= 1
-        else
-          tok[0] = :PARAM
-        end
+        tok[0] = :PARAM
       end
     end
 

lib/coffee_script/nodes.rb

@@ -212,11 +212,16 @@ module CoffeeScript
       @variable == :super
     end
 
+    def prefix
+      @new ? "new " : ''
+    end
+
     def compile(o={})
       o = super(o)
+      @splat = @arguments.detect {|a| a.is_a?(ArgSplatNode) }
+      return write(compile_splat(o)) if @splat
       args = @arguments.map{|a| a.compile(o) }.join(', ')
       return write(compile_super(args, o)) if super?
-      prefix = @new ? "new " : ''
       write("#{prefix}#{@variable.compile(o)}(#{args})")
     end
 
@@ -225,6 +230,17 @@ module CoffeeScript
       arg_part = args.empty? ? '' : ", #{args}"
       "#{o[:proto_assign]}.__superClass__.#{methname}.call(this#{arg_part})"
     end
+
+    def compile_splat(o)
+      meth = @variable.compile(o)
+      obj  = @variable.source || 'this'
+      args = @arguments.map do |arg|
+        code = arg.compile(o)
+        code = arg == @splat ? code : "[#{code}]"
+        arg.equal?(@arguments.first) ? code : ".concat(#{code})"
+      end
+      "#{prefix}#{meth}.apply(#{obj}, #{args.join('')})"
+    end
   end
 
   # Node to extend an object's prototype with an ancestor object.
@@ -247,7 +263,7 @@ module CoffeeScript
 
   # A value, indexed or dotted into, or vanilla.
   class ValueNode < Node
-    attr_reader :literal, :properties, :last
+    attr_reader :literal, :properties, :last, :source
 
     def initialize(literal, properties=[])
       @literal, @properties = literal, properties
@@ -280,6 +296,7 @@ module CoffeeScript
         val.respond_to?(:compile) ? val.compile(o) : val.to_s
       end
       @last = parts.last
+      @source = parts.length > 1 ? parts[0...-1].join('') : nil
       write(parts.join(''))
     end
   end
@@ -463,7 +480,7 @@ module CoffeeScript
       o.delete(:assign)
       o.delete(:no_wrap)
       name = o.delete(:immediate_assign)
-      if @params.last.is_a?(SplatNode)
+      if @params.last.is_a?(ParamSplatNode)
         splat = @params.pop
         splat.index = @params.length
         @body.unshift(splat)
@@ -476,7 +493,7 @@ module CoffeeScript
   end
 
   # A parameter splat in a function definition.
-  class SplatNode < Node
+  class ParamSplatNode < Node
     attr_accessor :index
     attr_reader :name
 
@@ -486,10 +503,23 @@ module CoffeeScript
 
     def compile(o={})
       o[:scope].find(@name)
-      "#{@name} = Array.prototype.slice.call(arguments, #{@index})"
+      write("#{@name} = Array.prototype.slice.call(arguments, #{@index})")
     end
   end
 
+  class ArgSplatNode < Node
+    attr_reader :value
+
+    def initialize(value)
+      @value = value
+    end
+
+    def compile(o={})
+      write(@value.compile(o))
+    end
+
+  end
+
   # An object literal.
   class ObjectNode < Node
     attr_reader :properties

test/fixtures/execution/test_splats.coffee

@@ -3,4 +3,33 @@ func: first, second, *rest =>
 
 result: func(1, 2, 3, 4, 5)
 
-print(result is "3 4 5")
+print(result is "3 4 5")
+
+
+gold: silver: bronze: the_field: null
+
+medalists: first, second, third, *rest =>
+  gold:       first
+  silver:     second
+  bronze:     third
+  the_field:  rest
+
+contenders: [
+  "Michael Phelps"
+  "Liu Xiang"
+  "Yao Ming"
+  "Allyson Felix"
+  "Shawn Johnson"
+  "Roman Sebrle"
+  "Guo Jingjing"
+  "Tyson Gay"
+  "Asafa Powell"
+  "Usain Bolt"
+]
+
+medalists("Mighty Mouse", *contenders)
+
+print(gold is "Mighty Mouse")
+print(silver is "Michael Phelps")
+print(bronze is "Liu Xiang")
+print(the_field.length is 8)

test/unit/test_execution.rb

@@ -2,30 +2,35 @@ require 'test_helper'
 
 class ExecutionTest < Test::Unit::TestCase
 
-  NO_WARNINGS = /\A(0 error\(s\), 0 warning\(s\)\n)+\Z/
-  ALLS_WELL   = /\A\n?(true\n)+\Z/m
+  NO_WARNINGS = "0 error(s), 0 warning(s)"
 
   # This is by far the most important test. It evaluates all of the
   # CoffeeScript in test/fixtures/execution, ensuring that all our
   # syntax actually works.
   def test_execution_of_coffeescript
     sources = ['test/fixtures/execution/*.coffee'].join(' ')
-    assert `bin/coffee -r #{sources}`.match(ALLS_WELL)
+    (`bin/coffee -r #{sources}`).split("\n").each do |line|
+      assert line == "true"
+    end
   end
 
   def test_lintless_coffeescript
-    lint_results = `bin/coffee -l test/fixtures/execution/*.coffee`
-    assert lint_results.match(NO_WARNINGS)
+    no_warnings `bin/coffee -l test/fixtures/execution/*.coffee`
   end
 
   def test_lintless_examples
-    lint_results = `bin/coffee -l examples/*.coffee`
-    assert lint_results.match(NO_WARNINGS)
+    no_warnings `bin/coffee -l examples/*.coffee`
   end
 
   def test_lintless_documentation
-    lint_results = `bin/coffee -l documentation/coffee/*.coffee`
-    assert lint_results.match(NO_WARNINGS)
+    no_warnings `bin/coffee -l documentation/coffee/*.coffee`
+  end
+
+
+  private
+
+  def no_warnings(output)
+    output.split("\n").each {|line| assert line == NO_WARNINGS }
   end
 
 end