parsec3 vs parsec-3.x

Christian Maeder Christian.Maeder at
Mon Jan 31 09:34:47 CET 2011

Am 29.01.2011 09:29, schrieb Roman Cheplyaka:
> * Antoine Latter <aslatter at> [2011-01-28 11:00:56-0600]
>>> I'd be happy to apply a patch for this.
>> To be more clear, to the 'parsec' package. I think Christian would
>> have to do it for the new 'parsec3' package.
> Perhaps I missed something. Can someone please explain why do we have to
> have two different third parsecs? Should one of them be deprecated? When
> would a user prefer one to another?

parsec-2 (and possibly its compatibility layer) may be deprecated or
superseded at some stage.

> I read the description of parsec3 package on hackage, it tries to give
> some explanation, but still:
> 1. It's not clear why "you may want to develop your code using this
>    subset of parsec3 modules". What advantage does it give?

The parsec3 package only ensures that you are not using the
compatibility layer for parsec2 given by the modules
Text.ParserCombinators.Parsec*, because parsec3 code developed with
these modules might not work with parsec2 or parsec-2.x.

> 2. If the packages are supposed to be compatible (as follows from the
>    above quote), the fact that they have different maintainers (and
>    different code repositories, I suppose) does not help.

(I've got not code repository for parsec3)

HTH Christian

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