[Haskell-cafe] How to make Prelude.read: no parse more verbose ...

Georg Sauthoff g_sauthoff at web.de
Wed Dec 19 11:53:18 EST 2007


I try to debug some existing Haskell-Code. Out of the blue I get a
'progname: Prelude.read: no parse'
error message from GHC.


Well, the code includes

# grep '\<read\>' *| wc -l
23 (sic!)

calls to the read fn.

Well, how do I compile a Haskell program in such a way, that I
get a useful error message from read? I mean, like the
filename/linenumber of the calling expression for starters.

Really crazy would be the possibility to print out a backtrace,
if some (library) function calls error ...

Best regards

Fortune : 'Real programmers don't comment their code.
           It was hard to write, it should be hard to understand.' ;)

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