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records with polymorphic variants?
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Date: | 2007-03-04 (16:49) |
From: | Eliot Handelman <eliot@g...> |
Subject: | Re: [Caml-list] Re: records with polymorphic variants? |
Lukasz Stafiniak wrote: > On 3/4/07, Zheng Li <li@pps.jussieu.fr> wrote: > > Yes, but the type f itself is not polymorphic, it is not [> f]. >> >> I guess you want the follows >> >> # type 'a r = { x : 'a } constraint 'a = [> f] >> type 'a r = { x : 'a; } constraint 'a = [> f ] >> # {x = "test"} >> Characters 6-12: >> { x = "test"};; >> ^^^^^^ >> This expression has type string but is here used with type [> f ] >> # {x = `B "test"} >> - : [> `A of int | `B of string ] r = {x = `B "test"} >> > Nice! I didn't realize this is possible. Thanks. Just what I was looking for -- many thanks. -- eliot