diff options
Diffstat (limited to 'lib/rubygems/util/list.rb')
-rw-r--r-- | lib/rubygems/util/list.rb | 44 |
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 |