#1702: type operator precedences don't work in contexts
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Reporter: [EMAIL PROTECTED] | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 6.8
Severity: normal | Keywords:
Difficulty: Unknown | Os: MacOS X
Testcase: | Architecture: powerpc
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Type contexts don't parse correctly when a type class is used infix. The
following example:
> infixr 4 :=:
> infixl 3 :+:
> infix 2 `Disjoint`
>
> labelZip :: (n :=: a `Disjoint` m :=: b) => n -> m -> [a] -> [b] ->
[n :=: a :+: m :=: b]
gives the error:
Type constructor `:=:' used as a class
In the type `(:=: n (a Disjoint (m :=: b))) =>
n -> m -> [a] -> [b] -> [(n :=: a) :+: (m :=: b)]'
In the type signature for `labelZip':
labelZip :: (:=: n (a Disjoint (m :=: b))) =>
n -> m -> [a] -> [b] -> [(n :=: a) :+: (m :=: b)]
where the parenthesised version works.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1702>
GHC <http://www.haskell.org/ghc/>
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