Cpphs does not expand macros inside haskell comments

[phischu]

The vector package makes use of cpp to abstract over inlining phases.
From "vector.h"

#define PHASE_STREAM [1]
#define PHASE_INNER  [0]

#define INLINE_STREAM INLINE PHASE_STREAM
#define INLINE_INNER  INLINE PHASE_INNER
....

From "Data/Vector/Fusion/Stream/Monadic.hs"

....
#include "vector.h"
....
-- | Attach a 'Size' hint to a 'Stream'
sized :: Stream m a -> Size -> Stream m a
{-# INLINE_STREAM sized #-}
sized (Stream step s _) sz = Stream step s sz
....

But cpphs ignores haskell comments when expanding macros.
From input.txt

#define INLINE_STREAM INLINE [1]
{-# INLINE_STREAM sized #-}
INLINE_STREAM

But

>readFile "input.txt" >>= runCpphs defaultCpphsOptions "input.txt" >>= putStrLn
#line 1 "reproduce.hs"

{-# INLINE_STREAM sized #-}
INLINE [1]

[UnkindPartition]

I'm not sure whether this should be considered a bug in cpphs or in vector.

@malcolmwallace what do you think?

[malcolmwallace]

Could be a feature rather than a bug. :-) You can try flipping the option to lex input as Haskell, and lex it as plaintext instead. defaultCpphsOptions{ boolopts = defaultBoolOptions { lang=False }}

[phischu]

Thank you this indeed solved my problem. I can now parse the vector package. Although this required an unrelated workaround. Should I submit a pull request to change the default behavior in hse-cpp? What would be the impact on the other packages?

[UnkindPartition]

Yeah, I guess submit a patch and include a comment with a link to this issue.