Opened 4 years ago

Closed 4 years ago

Last modified 3 years ago

#9972 closed bug (fixed)

t7861 gives unexpected result (deferred type error)

Reported by: luite Owned by:
Priority: normal Milestone: 8.0.1
Component: Compiler Version: 7.10.1-rc1
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'm not sure why validate does not trip on this, but the test case does not look obviously disabled to me, so I thought I'd just report it so at least it doesn't get unnoticed.

GHC 7.8:

"Hello"
t7861: t7861.hs:11:5:
    Couldn't match type ‘a’ with ‘[a]’
      ‘a’ is a rigid type variable bound by
          the type signature for f :: A a -> a at t7861.hs:10:6
    Expected type: A a -> a
      Actual type: A a -> [a]
    Relevant bindings include f :: A a -> a (bound at t7861.hs:11:1)
    In the expression: doA
    In an equation for ‘f’: f = doA
(deferred type error)

On GHC 7.10 the result is (both with and without optimization)

"Hello"
"Bad"

Change History (3)

comment:1 Changed 4 years ago by Simon Peyton Jones <simonpj@…>

In 678df4c2930c4aef61b083edb0f5c4d8c8914a76/ghc:

Fix up test for T7861

Fixes Trac #9972

comment:2 Changed 4 years ago by simonpj

Resolution: fixed
Status: newclosed

Ah yes, thanks

comment:3 Changed 3 years ago by thomie

Milestone: 8.0.1
Note: See TracTickets for help on using tickets.