[Haskell-beginners] Defining custom parser using Parsec

[Jimmy Wylie]

> This sounds awfully lot like a premature optimisation, which as we all
> know, is the root of evil :-)
>
> Why do you think that using Parsec will result in fewer
> transformations?  (It will most likely result in fewer transformations
> *that you see*, but that doesn't mean much.)
>
I think you're right.  I misunderstood the way the parsec library 
worked, and was trying to run before I could walk.
However, it is a priority that I make this tool as fast as possible (as 
close to drive speed as I can).  I wanted to take an "incremental" 
approach to optimization: writing small pieces, optimizing them, and 
then putting them together. I am also facing faculty skeptical that I 
can make things "fast" in haskell. (Currently, most DF applications are 
written in Python and C).

> http://therning.org/magnus/archives/289
> http://therning.org/magnus/archives/290
> http://therning.org/magnus/archives/295
> http://therning.org/magnus/archives/296
>
> /M
>
> [1]: http://hackage.haskell.org/package/attoparsec-0.8.1.1
>
Thanks for the references. They're great blog posts, very easy to 
follow.  I didn't realize how simple Parsec was to use, at least in the 
Monadic form.  For some reason, I thought it was more complex.

I do have one question though.  Do you always have to define your own 
Applicative instance for GenParser when trying to use the Applicative 
form? I noticed that both you and also RWH defined your own when 
explaining this form of Parsec.  Is there no standard Parsec.Applicative 
in the library.

Thanks again for your help,
Jimmy