Difference between revisions of "GHC/Error messages"

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("`foo' is not applied to enough type arguments")
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Example: TODO
 
Example: TODO
   
== "foo' is not a (visible) method of class `Bar'" ==
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== "`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.
 
This error message occurs when one tries to instantiate a class, but did not import the functions one tries to implement.

Revision as of 13:49, 3 December 2009

GHC error messages and their meaning.

"`foo' is not applied to enough type arguments"

TODO

Example: TODO

"`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

"Cannot match a monotype with `Foo'"

See this Haskell-Cafe thread.


"Parse error in pattern"

TODO

Example: TODO