[Haskell] Context of a pattern variable

[Malcolm Wallace]

Tomasz Zielonka <tomasz.zielonka at gmail.com> writes:

> I have an idea for a funny extension to pattern matching in Haskell. I
> wonder if it was proposed before, and most importantly, if it would be seen
> as useful.

Yes, it has been proposed before.  See

    Marcus Mohnen, "Context Patterns", Proceedings of IFL'96 (LNCS 1268)
    Marcus Mohnen, "Context Patterns II", Proceedings of IFL'97 (LNCS 1467)

Regards,
    Malcolm