From 4d4d6e4aea6565fa167296d16f94f4b768d5414e Mon Sep 17 00:00:00 2001 From: Adam Chlipala Date: Sat, 6 Jun 2009 14:09:30 -0400 Subject: List library additions; fix another substructure unification bug --- lib/ur/list.ur | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'lib/ur/list.ur') diff --git a/lib/ur/list.ur b/lib/ur/list.ur index 0776ff30..0aae9010 100644 --- a/lib/ur/list.ur +++ b/lib/ur/list.ur @@ -122,3 +122,31 @@ fun foldlMap [a] [b] [c] f = in fold [] end + +fun assoc [a] [b] (_ : eq a) (x : a) = + let + fun assoc' ls = + case ls of + [] => None + | (y, z) :: ls => + if x = y then + Some z + else + assoc' ls + in + assoc' + end + +fun search [a] [b] f = + let + fun search' ls = + case ls of + [] => None + | x :: ls => + case f x of + None => search' ls + | v => v + in + search' + end + -- cgit v1.2.3