[Haskell-cafe] monadic parser with Happy and Alex

[Manlio Perillo]

Hi.

I have completed a draft of a CSS lexer, using Alex.
http://hg.mperillo.ath.cx/haskell/webtools/file/tip/src/CSS/Lexer.x

The lexer use the posn wrapper.

Now I'm starting to write the parser with Happy, however for the final 
product I would like to:
1) Be able to do I/O in the lexer, for stylesheets inclusion
    (@import rule)
2) be able to keep state in the parser (or lexer?), for character
    transcoding (@charset rule)


This should be possible with Happy (and there are some example), however 
  I don't find examples that make use of a lexer written with Alex.

Should I write a lexer using only the Alex basic interface (without 
wrappers)?



Thanks   Manlio Perillo