view tests/type_classMod2.ur @ 1240:beb67ff4c8a0

'also' policies and policy reduction; calendar in good shape
author Adam Chlipala <adamc@hcoop.net>
date Thu, 15 Apr 2010 10:00:30 -0400
parents 71bafe66dbe1
children
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line source
signature S = sig
        class c
        val default : t :: Type -> c t -> t

        val string_c : c string
        val int_c : c int
end

structure M : S = struct
        class c t = t
        val default = fn t :: Type => fn v : c t => v

        val int_c : c int = 0
        val string_c : c string = "Hi"
end

val hi = M.default [string] _
val zero = M.default [int] _