[Haskell-cafe] Re: regex package for yhc?
haskell at list.mightyreason.com
Thu Dec 6 16:41:47 EST 2007
Thomas Hartman wrote:
> Is there some way to use any of the various regex packages on hackage
> via yhc? Has anyone installed one them successfully?
> I'd like regex-tdfa, but would settle for regex-posix, or really,
> anything that brings the convenience of regex to yhc.
> In general, is there a straightforward way to install "extralibs" type
> packages for universal "import" availability in yhc?
> Is there a cabal equivalent for yhc? Documentation pointer would be
> appreciated; I searched but couldn't find anything. Maybe not using the
> right keywords...
I put the regex-* packages on hackage. I have had no reports of use with yhc.
Some of the convenience comes from the regex-base font end.
The high level (=~) and 'match' regex API depends on the MPTC's of regex-base,
and these currently use functional dependencies. This works on GHC and Hugs.
I cannot quickly find on http://www.haskell.org/haskellwiki/Yhc what YHC supports.
The regex-posix package is a backend, the oldest. It exposes the platform's
POSIX regex.h library through the FFI calls in Text/Regex/Posix/Wrap.hsc. This
C api is further layered in the data type specific modules:
And all of that is re-exported in
A similar design is followed by the regex-pcre backend (and the deprecated
One _could_ refactor regex-posix into two packages. One would give standalone
accesses to the backend and simply be Haskell98 + FFI. The other would declare
the instances to make this available though regex-base.
The regex-tdfa backend is my own creation, and is not a wrapper for another
library. It uses some non-Haskell98 syntax, such as the "mdo" syntactic sugar
for MonadFix (aka recursive do).
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