Opened 8 years ago

Last modified 23 months ago

#3547 new feature request

Improve granularity of UndecidableInstances

Reported by: ksf Owned by:
Priority: low Milestone:
Component: Compiler Version: 6.10.4
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

Currently, as a LANGUAGE pragma, UndecidableInstances can only be set once per file: Assuming that there are enough occasions where one would only need to enable it for one or two instances in a bigger source and considering that the warnings emitted if UndecidableInstances is not set are actually useful, it makes sense to support enabling the extension only on a per-instance basis.

proposed syntax:

{-# LANGUAGE UndecidableInstances #-} 
[code]
{-# NOLANGUAGE UndecidableInstances #-}

Change History (10)

comment:1 Changed 8 years ago by igloo

difficulty: Unknown
Milestone: 6.14.1

comment:2 Changed 7 years ago by igloo

Milestone: 7.0.17.0.2

comment:3 Changed 7 years ago by igloo

Milestone: 7.0.27.2.1

comment:4 Changed 6 years ago by igloo

Milestone: 7.2.17.4.1

comment:5 Changed 6 years ago by igloo

Milestone: 7.4.17.6.1
Priority: normallow

comment:6 Changed 5 years ago by igloo

Milestone: 7.6.17.6.2

comment:7 Changed 3 years ago by thoughtpolice

Milestone: 7.6.27.10.1

Moving to 7.10.1.

comment:8 Changed 3 years ago by thoughtpolice

Milestone: 7.10.17.12.1

Moving to 7.12.1 milestone; if you feel this is an error and should be addressed sooner, please move it back to the 7.10.1 milestone.

comment:9 Changed 2 years ago by thoughtpolice

Milestone: 7.12.18.0.1

Milestone renamed

comment:10 Changed 23 months ago by thomie

Milestone: 8.0.1
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