[m-users.] Predicate inside of maybe ?

[Volker Wysk]

Hi!

I'm puzzled. I'm trying to store a predicate inside of a maybe. The
following code:

:- type argdesc(Arg)
 ---> argdesc(
        (...)
        maybe(pred(string)::pred(in) is det) 
      ).

... causes this compiler error message:

colipa.m:255: In type definition: in the first argument of higher-order
colipa.m:255: predicate type:
colipa.m:255: error: missing `::mode' suffix.


How should this be done?

Bye, Volker
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: This is a digitally signed message part
URL: <http://lists.mercurylang.org/archives/users/attachments/20220927/700bc0cf/attachment.sig>