[Haskell-cafe] What is the consensus about -fwarn-unused-do-bind ?

John Meacham john at repetae.net
Wed Apr 14 14:42:18 EDT 2010

On Fri, Apr 09, 2010 at 09:07:29AM -0700, Bryan O'Sullivan wrote:
> On Fri, Apr 9, 2010 at 6:44 AM, Ivan Lazar Miljenovic <
> ivan.miljenovic at gmail.com> wrote:
> > As of 6.12.1, the new -fwarn-unused-do-bind warning is activated with
> > -Wall.  This is based off a bug report by Neil Mitchell:
> > http://hackage.haskell.org/trac/ghc/ticket/3263 .
> >
> > However, does it make sense for this to be turned on with -Wall?
> Personally, I find it to be tremendously noisy and unhelpful, and I always
> edit my .cabal files to turn it off. I think of it as a usability
> regression.

I strongly agree.

I do not even think it is bad style to ignore the result of a monad,
depending on the particular monad used, it could be extremely common. If
anything there should be a pragma one can attach to ceratin functions to
warn if the result is unused, like 'mapM'. This would be similar to what
gcc does, where you can specify an attribute saying a functions result
should be used or the compiler should complain.


John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/

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