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comparison tests/case.lac @ 171:c7a6e6dbc318

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Elaborating some basic pattern matching
author Adam Chlipala <adamc@hcoop.net>
date Thu, 31 Jul 2008 10:06:27 -0400
parents a158f8c5aa55
children
comparison
equal deleted inserted replaced
170:a158f8c5aa55 171:c7a6e6dbc318
6 6
7 val out = fn x : u => case x of C y => y | D => A 7 val out = fn x : u => case x of C y => y | D => A
8 8
9 datatype nat = O | S of nat 9 datatype nat = O | S of nat
10 10
11 val is_two = fn x : int_list => 11 val is_two = fn x : nat =>
12 case x of S (S O) => A | _ => B 12 case x of S (S O) => A | _ => B
13
14 val zero_is_two = is_two O
15 val one_is_two = is_two (S O)
16 val two_is_two = is_two (S (S O))