lstrojny/functional-php — pull request #10 by maxbeutel (2011-11-27 12:25:19+00:00)
Title: added c impl of unique compatible with userland impl

Didnt use a linked-list for lookup though, iterating over a linked list is still O(n) in worst case, most of the implementation functional_in_array is similiar to php´s own in_array function.