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GHC/Error messages

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(will fill this out once i find a small example)
 
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GHC error messages and their meaning.
 
GHC error messages and their meaning.
   
== Parse error in pattern ==
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== "`foo' is not applied to enough type arguments" ==
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TODO
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Example: TODO
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== "`foo' is not a (visible) method of class `Bar'" ==
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This error message occurs when one tries to instantiate a class, but did not import the functions one tries to implement.
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Example:
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<haskell>
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import Prelude hiding ((==))
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data Foo = Foo
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instance Eq Foo where
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(==) a b = True
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</haskell>
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== "Cannot match a monotype with `Foo'" ==
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See [http://www.haskell.org/pipermail/haskell-cafe/2009-October/067806.html this] Haskell-Cafe thread.
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== "Parse error in pattern" ==
   
 
TODO
 
TODO

Latest revision as of 13:49, 3 December 2009

GHC error messages and their meaning.

Contents

[edit] 1 "`foo' is not applied to enough type arguments"

TODO

Example: TODO

[edit] 2 "`foo' is not a (visible) method of class `Bar'"

This error message occurs when one tries to instantiate a class, but did not import the functions one tries to implement.

Example:

import Prelude hiding ((==))
 
data Foo = Foo
 
instance Eq Foo where 
    (==) a b = True

[edit] 3 "Cannot match a monotype with `Foo'"

See this Haskell-Cafe thread.


[edit] 4 "Parse error in pattern"

TODO

Example: TODO