[Haskell] [mini-announce] Attribute grammars in happy

Robert Dockins robdockins at fastmail.fm
Tue Oct 25 18:26:57 EDT 2005

Fellow Haskellers,

I have hacked up Happy (http://www.haskell.org/happy/) to support attribute 
grammars.  Attribute grammars are a way of annotating context-free grammars 
to support syntax directed translation and the checking of context-sensitive 

What we have:

 * Support for attribute grammars using a slight modification to
   the Happy grammar syntax

 * Haskell 98! No language extensions required.

 * Support for all well-defined attribute grammars (conjecture,
   but I'm pretty sure)

What we don't have:

 * Support for GLR parsing (mostly because I don't completely understand it)

 * Checks for proper attribute usage

There is a darcs repo at based on the Happy 1.15 source distribution at:


And documentation for the extension can be found at:


If there is sufficient interest I can clean up the code and write test cases 
and submit an official patch to Happy.  Let me know what you think. Comments 
and suggestions are welcome.

Robert Dockins

P.S. Discussion should probably move to haskell-cafe.

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