diff options
author | Adam Chlipala <adamc@hcoop.net> | 2009-06-06 14:09:30 -0400 |
---|---|---|
committer | Adam Chlipala <adamc@hcoop.net> | 2009-06-06 14:09:30 -0400 |
commit | 3ad616e1188527cfd92bf322d5884fa633d40208 (patch) | |
tree | 1d3da14055d91262a0e36315573406b564790fdc /lib/ur/list.ur | |
parent | 07f80839011b33db760cdac421ccea6226b07111 (diff) |
List library additions; fix another substructure unification bug
Diffstat (limited to 'lib/ur/list.ur')
-rw-r--r-- | lib/ur/list.ur | 28 |
1 files changed, 28 insertions, 0 deletions
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 + |