It well might.  I believe you can do this yourself.  Jeremy Shaw wrote a parser for Debian control files, which was useless on the really large package index files.  He switched it over to using bytestrings and that solved the problem.  You can find the code in a darcs repository at:   
<a href="http://src.seereason.com/haskell-debian">http://src.seereason.com/haskell-debian</a>.&nbsp; It may reference other libraries hosted at that URL, which you can browse from the base URL.<br><br><br><div class="gmail_quote">
On Jan 24, 2008 1:34 PM, Matthew Pocock &lt;<a href="mailto:matthew.pocock@ncl.ac.uk">matthew.pocock@ncl.ac.uk</a>&gt; wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Would a bytestring-backed implementation of parsec solve my problems? Is there<br>such a beast out there?<br><br>Matthew<br>_______________________________________________<br>Haskell-Cafe mailing list<br><a href="mailto:Haskell-Cafe@haskell.org">
Haskell-Cafe@haskell.org</a><br><a href="http://www.haskell.org/mailman/listinfo/haskell-cafe" target="_blank">http://www.haskell.org/mailman/listinfo/haskell-cafe</a><br></blockquote></div><br>