Re: [Haskell-cafe] monadic parser with Happy and Alex

On Sat, 2008-10-04 at 17:05 +0200, Manlio Perillo wrote:

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.

See c2hs or Language.C it uses a monadic lexer. Duncan