[Haskell-cafe] Prelude.undefined

Ketil Malde ketil at malde.org
Thu Mar 4 16:37:48 EST 2010

Ivan Miljenovic <ivan.miljenovic at gmail.com> writes:

>> <GHC.Err.CAF>Test: Prelude.undefined

> Are you matching all patterns?  When compiling with -Wall does it make
> any complaints?

How would this help?  'Prelude.undefined' happens because somewhere
you're trying to evaluate a value defined with that particular literal,
doesn't it?

Using this in a library seems to me to be in poor taste, but grepping
the code should reveal it, if you're sure that's where the problem is
hiding.  I generally replace any 'undefined's with 'error string', with
each 'string' unique for that position.

If I haven't seen further, it is by standing in the footprints of giants

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