Mercurial > urweb
view tests/type_classMod2.ur @ 1886:b7cd3c7c7edd
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> |
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date | Mon, 04 Nov 2013 15:14:23 -0500 |
parents | 71bafe66dbe1 |
children |
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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] _