Mercurial > urweb
diff demo/list.ur @ 397:4d519baf357c
ListShop skeleton
author | Adam Chlipala <adamc@hcoop.net> |
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date | Tue, 21 Oct 2008 12:06:35 -0400 |
parents | |
children | 7ef4b2911b09 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/demo/list.ur Tue Oct 21 12:06:35 2008 -0400 @@ -0,0 +1,15 @@ +datatype list t = Nil | Cons of t * list t + +fun length' (t ::: Type) (ls : list t) (acc : int) = + case ls of + Nil => acc + | Cons (_, ls') => length' ls' (acc + 1) + +fun length (t ::: Type) (ls : list t) = length' ls 0 + +fun rev' (t ::: Type) (ls : list t) (acc : list t) = + case ls of + Nil => acc + | Cons (x, ls') => rev' ls' (Cons (x, acc)) + +fun rev (t ::: Type) (ls : list t) = rev' ls Nil