Proposal: Add concatMapM function (#2042)

Aaron Denney wnoise at
Fri Feb 1 04:01:24 EST 2008

On 2008-02-01, Roman Leshchinskiy <rl at> wrote:
> Bulat Ziganshin wrote:
>> the right way to deal with "modifiers" is to attach them to the Handle
>> itself like this:
>> f <- openFile "name" >>= withLocking >>= withEncoding utf8
> IMO, global state is never "the right way" if it can be avoided. It will 
> always lead to problems. Especially in a functional language like Haskell.

This isn't global state, but local to the handle, and only affects where
the handle is passed in.  It's just extending an opaque data type.

Aaron Denney

More information about the Libraries mailing list