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annotate tests/type_classMod2.ur @ 1886:b7cd3c7c7edd

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Interpret 'table' signature items more flexibly, automatically adding (Ur) constraints to support a kind of subtyping over (SQL) constraint sets
author Adam Chlipala <adam@chlipala.net>
date Mon, 04 Nov 2013 15:14:23 -0500
parents 71bafe66dbe1
children
rev   line source
adamc@218 1 signature S = sig
adamc@218 2 class c
adamc@218 3 val default : t :: Type -> c t -> t
adamc@218 4
adamc@218 5 val string_c : c string
adamc@218 6 val int_c : c int
adamc@218 7 end
adamc@218 8
adamc@218 9 structure M : S = struct
adamc@218 10 class c t = t
adamc@218 11 val default = fn t :: Type => fn v : c t => v
adamc@218 12
adamc@218 13 val int_c : c int = 0
adamc@218 14 val string_c : c string = "Hi"
adamc@218 15 end
adamc@218 16
adamc@218 17 val hi = M.default [string] _
adamc@218 18 val zero = M.default [int] _