[GHC] #595: Overhaul GHC's overlapping/non-exhaustive pattern checking

[GHC]

#595: Overhaul GHC's overlapping/non-exhaustive pattern checking
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 Reporter:  simonmar  |        Owner:      
     Type:  task      |       Status:  new 
 Priority:  normal    |    Milestone:      
Component:  Compiler  |      Version:  None
 Severity:  normal    |   Resolution:  None
 Keywords:            |  
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Changes (by simonmar):

  * component:  None => Compiler

Old description:

> {{{
> GHC has a module in the desugarer (Check) which checks whether patterns
> are overlapping and/or exhaustive, to support the flags -fwarn-
> overlapping-patterns and -fwarn-non-exhaustive-patterns.  The code is old
> and crufty, and has several outstanding bugs.  A rewrite is needed.
> }}}

New description:

 GHC has a module in the desugarer (Check) which checks whether patterns
 are overlapping and/or exhaustive, to support the flags -fwarn-
 overlapping-patterns and -fwarn-non-exhaustive-patterns.  The code is old
 and crufty, and has several outstanding bugs.  A rewrite is needed.

-- 
Ticket URL: <http://cvs.haskell.org/trac/ghc/ticket/595>
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