haddock-2.3.0 literate comments discarded from .lhs input

David Waern david.waern at gmail.com
Fri Feb 6 05:48:48 EST 2009

2009/2/6 Alistair Bayley <alistair at abayley.org>:
>>> [1 of 1] Compiling Test.Fail        ( Test\Fail.hs, Test\Fail.o )
>>> Test\Fail.hs:11:26:
>>>    Can't make a derived instance of `Typeable Fail'
>>>      (You need -XDeriveDataTypeable to derive an instance for this class)
>>>    In the data type declaration for `Fail'
>> Are you processing the above module but it is called Test.Fail in
>> reality? Have you stripped out a deriving statement from the example
>> above? I'm very confused by this message :)
> Sorry, my mistake. I pasted the error message from a different
> problem. This is the error I get from haddock:
> C:\bayleya\eclipse\workspace\takusen\src>haddock -h --odir=doc Test/Haddock.lhs
> Cannot find documentation for: $named_block

Okay, then I understand.

My guess is (without looking at ghc code) that ghc just throws the
literate comments away before lexing the file. This means that the
Haddock comments won't be recognized.

As you say, there is also an unlitter in Cabal. I don't remember if it
is invoked when using Haddock 2, but if it is, it would solve this


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