* lib/rubygems: Import RubyGems 2.1

* test/rubygems:  Ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41873 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 44 insertions, 0 deletions

diff --git a/lib/rubygems/util/list.rb b/lib/rubygems/util/list.rb
new file mode 100644
index 0000000000..9f540adcc1
--- /dev/null
+++ b/lib/rubygems/util/list.rb
@@ -0,0 +1,44 @@
+module Gem
+  List = Struct.new(:value, :tail)
+
+  class List
+    def each
+      n = self
+      while n
+        yield n.value
+        n = n.tail
+      end
+    end
+
+    def to_a
+      ary = []
+      n = self
+      while n
+        ary.unshift n.value
+        n = n.tail
+      end
+
+      ary
+    end
+
+    def find
+      n = self
+      while n
+        v = n.value
+        return v if yield(v)
+        n = n.tail
+      end
+
+      nil
+    end
+
+    def prepend(value)
+      List.new value, self
+    end
+
+    def self.prepend(list, value)
+      return List.new(value) unless list
+      List.new value, list
+    end
+  end
+end