#14479 closed bug (fixed)

Partial type signatures and generalisation

Reported by: simonpj Owned by:
Priority: normal Milestone:
Component: Compiler Version: 8.2.1
Keywords: Cc:
Operating System: Unknown/Multiple Architecture: Unknown/Multiple
Type of failure: None/Unknown Test Case: partial-sigs/should_fail/T14479
Blocked By: Blocking:
Related Tickets: Differential Rev(s):
Wiki Page:

Description

This should be rejected

foo :: Num a => a -> a
foo x = g x x
 where
   g :: Num b => _ -> b -> b
   g _ y = x + y

But it isn't.

Change History (2)

comment:1 Changed 12 months ago by Simon Peyton Jones <simonpj@…>

In 72938f58/ghc:

Check for bogus quantified tyvars in partial type sigs

This fixes Trac #14479.  Not difficult.

See Note [Quantification and partial signatures] Wrinkle 4,
in TcSimplify.

comment:2 Changed 12 months ago by simonpj

Resolution: fixed
Status: newclosed
Test Case: partial-sigs/should_fail/T14479
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