#4235: deriving Enum fails for data instances
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Reporter: nestra | Owner:
Type: bug | Status: closed
Priority: normal | Milestone: 7.0.1
Component: Compiler (Type checker) | Version: 6.12.3
Resolution: fixed | Keywords: instance
deriving, type families, GADTs
Testcase: indexed-types/should_run/T4235 | Blockedby:
Difficulty: | Os: Linux
Blocking: | Architecture: x86_64 (amd64)
Failure: Compile-time performance bug |
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Comment(by simonpj):
Turned out there was a second bug relating to enumerations that have a
phantom type variable, that made the regresssion test fail with -O. Fixed
by
{{{
Wed Oct 6 08:52:23 PDT 2010 [email protected]
* Fix test T4235 with -O
The tag2Enum rule wasn't doing the right thing for
enumerations with a phantom type parameter, like
data T a = A | B
M ./compiler/prelude/PrelRules.lhs -14 +10
}}}
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4235#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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