Question about Haskell AST

Max Bolingbroke batterseapower at
Tue Jan 25 10:34:33 CET 2011

On 24 January 2011 17:20, Jane Ren <j2ren at> wrote:
> When I try this, I get
> "AstWalker: panic! (the 'impossible' happened)
>  (GHC version 7.0.1 for x86_64-apple-darwin):
>        lexical error at character 'i'

It looks like you need to add the CPP extension to the DynFlags:

  setSessionDynFlags dflags { extensionFlags = Opt_Cpp : extensionFlags dflags }

You might have to iterate a few times to find the correct set of flags.


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