Mercurial > urweb
diff demo/list.ur @ 501:7ef4b2911b09
Some demo improvements
author | Adam Chlipala <adamc@hcoop.net> |
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date | Thu, 20 Nov 2008 11:34:36 -0500 |
parents | 4d519baf357c |
children | 669ac5e9a69e |
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--- a/demo/list.ur Thu Nov 20 10:44:28 2008 -0500 +++ b/demo/list.ur Thu Nov 20 11:34:36 2008 -0500 @@ -1,15 +1,21 @@ 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) = + let + fun length' (ls : list t) (acc : int) = + case ls of + Nil => acc + | Cons (_, ls') => length' ls' (acc + 1) + in + length' ls 0 + end -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 +fun rev (t ::: Type) (ls : list t) = + let + fun rev' (ls : list t) (acc : list t) = + case ls of + Nil => acc + | Cons (x, ls') => rev' ls' (Cons (x, acc)) + in + rev' ls Nil + end