Mercurial > urweb
annotate demo/list.ur @ 441:c5335613f31e
CURRENT_TIMESTAMP
author | Adam Chlipala <adamc@hcoop.net> |
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date | Thu, 30 Oct 2008 15:33:28 -0400 |
parents | 4d519baf357c |
children | 7ef4b2911b09 |
rev | line source |
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adamc@397 | 1 datatype list t = Nil | Cons of t * list t |
adamc@397 | 2 |
adamc@397 | 3 fun length' (t ::: Type) (ls : list t) (acc : int) = |
adamc@397 | 4 case ls of |
adamc@397 | 5 Nil => acc |
adamc@397 | 6 | Cons (_, ls') => length' ls' (acc + 1) |
adamc@397 | 7 |
adamc@397 | 8 fun length (t ::: Type) (ls : list t) = length' ls 0 |
adamc@397 | 9 |
adamc@397 | 10 fun rev' (t ::: Type) (ls : list t) (acc : list t) = |
adamc@397 | 11 case ls of |
adamc@397 | 12 Nil => acc |
adamc@397 | 13 | Cons (x, ls') => rev' ls' (Cons (x, acc)) |
adamc@397 | 14 |
adamc@397 | 15 fun rev (t ::: Type) (ls : list t) = rev' ls Nil |