GHC/Error messages
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m (→"Foo' is not a (visible) method of class `Bar'") |
("Cannot match a monotype with `Foo'") |
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GHC error messages and their meaning. | GHC error messages and their meaning. | ||
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== "Foo' is not a (visible) method of class `Bar'" == | == "Foo' is not a (visible) method of class `Bar'" == | ||
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(==) a b = True | (==) a b = True | ||
</haskell> | </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" == | ||
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| + | TODO | ||
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| + | Example: TODO | ||
Revision as of 06:20, 15 October 2009
GHC error messages and their meaning.
1 "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
2 "Cannot match a monotype with `Foo'"
See this Haskell-Cafe thread.
3 "Parse error in pattern"
TODO
Example: TODO
