Haskell Platform Proposal: add transformers and revise the mtl package to depend on it

Conrad Parker conrad at metadecks.org
Thu Sep 16 21:20:20 EDT 2010

+1 for the proposal in general

On 16 September 2010 23:47, Felipe Lessa <felipe.lessa at gmail.com> wrote:
> On Thu, Sep 16, 2010 at 11:42 AM, Duncan Coutts
> <duncan.coutts at googlemail.com> wrote:
>>> This is probably the last chance we have to deprecate the name 'mtl'.
>> Is this actually a problem?
> Not really.  It's just for consistency.

I like Felipe's idea of deprecating the name mtl (in the form of the
not-yet-existing library mtl-2) in favour of the existing
(name+library) monads-fd.

Many actively maintained packages already have a
transformers+monads-fd dependency anyway. I'd expect the changes of
this proposal will take about a year or so to shake out (eg. by the
time the change is reflected in Debian stable / on random hackers'
machines), and introducing the mtl-2 name would encourage maintainers
to have (mtl-2 || monads-fd) dependencies in cabal files during that
time. I think it'd be neater to just stick to the existing monads-fd

(Also I think monads-fd is a more descriptive name than mtl, but
perhaps I just don't like TLAs :)


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