Opened 13 months ago

Last modified 13 months ago

#15522 new bug

Cannot bind symbolic names in a rule

Reported by: goldfire Owned by:
Priority: normal Milestone: 8.6.1
Component: Documentation Version: 8.4.3
Keywords: Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: None/Unknown Test Case:
Blocked By: Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:

Description

I assumed the following would be accepted:

{-# RULES "blah" forall (+++). id (+++) = (+++) #-}

But it's not, as the parser doesn't like my +++. I find this inconsistent with the way that GHC normally treats term-level variables, which can generally be symbolic.

That said, I have no need for this feature, and allowing it creates more headaches (it potentially creates parsing challenges, especially with #2600; and soon people will want to specify fixities). I thus propose simply to document that we don't allow it and move on.

If you agree (for any definition of "you"), please post, as I'd love other opinions.

Change History (1)

comment:1 Changed 13 months ago by monoidal

+1, this doesn't seem to be worth the maintenance burden.

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