Added Enumerable#first_match

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2578 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Added Enumerable#first_match [Nicholas Seckar]
+
 * Fixed that Time#change should also reset usec when also resetting minutes #2459 [ikeda@dream.big.or.jp]
 
 * Fix Logger compatibility for distributions that don't keep Ruby and its standard library in sync.

activesupport/lib/active_support/core_ext/enumerable.rb

@@ -0,0 +1,9 @@
+module Enumerable
+  def first_match
+    match = nil
+    each do |items|
+      break if match = yield(items)
+    end
+    match
+  end
+end

activesupport/test/core_ext/enumerable_test.rb

@@ -0,0 +1,15 @@
+require 'test/unit'
+require File.dirname(__FILE__) + '/../../lib/active_support/core_ext/enumerable'
+
+class EnumerableTests < Test::Unit::TestCase
+  
+  def test_first_match_no_match
+    [[1, 2, 3, 4, 5], (1..9)].each {|a| a.first_match {|x| x > 10}}
+  end
+  
+  def test_first_match_with_match
+    assert_equal true, [1, 2, 3, 4, 5, 6].first_match {|x| x > 4}
+    assert_equal true, (1..10).first_match {|x| x > 9}
+    assert_equal :aba, {:a => 10, :aba => 50, :bac => 40}.first_match {|k, v| k if v > 45}
+  end
+end