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  • Glasgow Haskell CompilerGlasgow Haskell Compiler
  • GHCGHC
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  • #4325
Closed
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Issue created Sep 19, 2010 by Ian Lynagh <igloo@earth.li>@trac-igloo

Deriving regression

First reported here: http://www.haskell.org/pipermail/cvs-ghc/2010-September/056008.html

This module:

module Foo where

data Ord a => Heap a b = Empty | Node a b [Heap a b]
    deriving Eq

is rejected by HEAD:

$ hd -c h.hs

h.hs:1:1:
    No instance for (Ord a)
      arising from a use of `Node'
    In the pattern: Node _ _ _
    In an equation for `$con2tag_Heap': $con2tag_Heap (Node _ _ _) = 1#
Trac metadata
Trac field Value
Version 6.13
Type Bug
TypeOfFailure OtherFailure
Priority highest
Resolution Unresolved
Component Compiler
Test case
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