2014 Applicative => Monad proposal

[Ivan Lazar Miljenovic]

On 24 May 2013 05:39, David Luposchainsky <dluposchainsky at googlemail.com> wrote:
> Hello libraries,
>
> it's on! Time to tackle the Applicative-Monad issue, hopefully once and
> for all. Over the last couple of weeks I've looked through previous
> proposals, asked #haskell about their opinions, and compiled it all into
> one file that sums up what I made of that. It's a bit long for an email
> and uses markdown, so I'll just provide links at the end of this mail
> instead of pasting it in here. In there, the whole thing and how to
> approach it is explained in more detail. Here's an abstract of what it
> the proposal consists of:
>
>
> - Don't break compatibility
> - Apply it gently
>
> - Applicative m => Monad m
> - Applicative into Prelude (and therefore into the Report)
> - (Alternative m, Monad m) => MonadPlus m
> - Promote `join` into the Monad typeclass

How about removing `return' from the Monad typeclass and just making
it an alias for pure?  Or is it being kept just to minimise breakage
from existing instance declarations?

Anyway, I agree with the first three; I'm not fussed either way with
including `join' into the typeclass.

>
>
> Let's make this happen! I'm going to give a ballpark discussion period
> of four weeks, but since I can imagine this discussion could become
> quite complex we shouldn't take it too serious. I'll summarize what's
> been going on periodically though.
>
> David
>
>
>
> Links:
>
> The proposal text on Github (link fixed, sorry for the deadlink yesterday):
> https://github.com/quchen/articles/blob/master/applicative_monad.md
> (This file is subject to changes, depending on how this discussion goes.
> I'll try to make it reflect the current consensus.)
>
> And just in case Github silentbans me again for submitting too many
> edits to my Gist (grrr), here's a copy of the file on HPaste as backup:
> http://hpaste.org/88423
>
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-- 
Ivan Lazar Miljenovic
Ivan.Miljenovic at gmail.com
http://IvanMiljenovic.wordpress.com