From 7ee5be674d9456f15ea419fc9a69ee3b635fcc17 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Sat, 2 Jan 2010 00:20:24 -0500
Subject: [PATCH] adding splice literals, with tests

---
 lib/coffee_script/nodes.rb                  | 16 ++++++++++++++--
 test/fixtures/execution/test_splices.coffee |  5 +++++
 2 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 test/fixtures/execution/test_splices.coffee

diff --git a/lib/coffee_script/nodes.rb b/lib/coffee_script/nodes.rb
index 2ea0a336..29ab1aa1 100644
--- a/lib/coffee_script/nodes.rb
+++ b/lib/coffee_script/nodes.rb
@@ -294,8 +294,10 @@ module CoffeeScript
     end
 
     def compile(o={})
-      o = super(o)
-      parts = [@literal, @properties].flatten.map do |val|
+      o     = super(o)
+      only  = o.delete(:only_first)
+      props = only ? @properties[0...-1] : @properties
+      parts = [@literal, props].flatten.map do |val|
         val.respond_to?(:compile) ? val.compile(o) : val.to_s
       end
       @last = parts.last
@@ -413,6 +415,7 @@ module CoffeeScript
 
     def compile(o={})
       o = super(o)
+      return compile_splice(o) if @variable.properties.last.is_a?(SliceNode)
       name      = @variable.compile(o)
       last      = @variable.last.to_s.sub(LEADING_DOT, '')
       proto     = name[PROTO_ASSIGN, 1]
@@ -424,6 +427,15 @@ module CoffeeScript
       val = "#{name} = #{@value.compile(o)}"
       write(o[:return] && !@value.custom_return? ? "#{o[:indent]}return (#{val})" : val)
     end
+
+    def compile_splice(o)
+      var   = @variable.compile(o.merge(:only_first => true))
+      range = @variable.properties.last.range
+      plus  = range.exclusive? ? '' : ' + 1'
+      from  = range.from.compile(o)
+      to    = "#{range.to.compile(o)} - #{from}#{plus}"
+      write("#{var}.splice.apply(#{var}, [#{from}, #{to}].concat(#{@value.compile(o)}))")
+    end
   end
 
   # Simple Arithmetic and logical operations. Performs some conversion from
diff --git a/test/fixtures/execution/test_splices.coffee b/test/fixtures/execution/test_splices.coffee
new file mode 100644
index 00000000..0ac1135f
--- /dev/null
+++ b/test/fixtures/execution/test_splices.coffee
@@ -0,0 +1,5 @@
+array: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+
+array[5..10]: [0, 0, 0]
+
+print(array.join(' ') is '0 1 2 3 4 0 0 0')
\ No newline at end of file