[Haskell-cafe] Re: Optimizing Parsec 3 -- was: Wiki software?

Evan Laforge qdunkan at gmail.com
Sat Dec 5 00:01:49 EST 2009

On Fri, Dec 4, 2009 at 1:09 PM, John MacFarlane <jgm at berkeley.edu> wrote:
>> On Mon, Nov 23, 2009 at 12:29 PM, Antoine Latter <aslatter at gmail.com> wrote:
>> I finally had some time to test it.  After running it multiple times
>> (of course, it would be nice to use criterion here), I'm getting
>> numbers in this neighborhood:
> I used criterion to compare pandoc compiled with parsec2 to
> pandoc compiled with your version of parsec3.  (The benchmark
> is converting testsuite.txt from markdown to HTML.) The difference was
> minor:

Very nice, I was interested in parsec 3 but scared off by the reports
of slowness, as I'm sure many others were.

Is there any document out there describing the differences between 2
and 3?  I gathered 3 allows more flexibility wrt the input, so you can
more easily use ByteString or Text, but it would be nice to have a doc
saying what the new features are and why we should be interested in

The old parsec docs were out of date even for parsec 2, and looks like
they haven't been updated.  The new ones look like they use haddock
which is great, that was a gripe I had about the old doc.  However,
the haddock docs are less friendly than the old doc.  So my suggestion
is to paste the old introduction (with Daan permission, of course) or
something similar into the Text.Parsec description field, along with
links to more detailed descriptions and tutorial in the style of v2 on
haskell.org along with a 2 vs. 3 doc, even if they're sketchy and

Or if it's ok I could just send some darcs patches :)

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