<div dir="ltr">Vanessa, I'm not proposing to replace base with relude in libraries like dir-traverse. Sorry if I wasn't clear enough, I didn't mean to introduce more confusion.<div><br></div><div>I don't use `relude` in my libraries as well because I prefer a low amount of external dependencies and I usually use alternative prelude only in big applications.</div><div><br>As David mentioned, I indeed just wanted to show one more place where `foldMapA` is introduced because it's not in base. Having `foldMapA` in base will make `relude` even better because it will have even fewer custom things in favour of mere reexports from base. I also think that if some data type / function has already been in some alternative prelude for some time, it could be a good addition to base.</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, May 9, 2019 at 10:28 PM Vanessa McHale <<a href="mailto:vanessa.mchale@iohk.io" target="_blank">vanessa.mchale@iohk.io</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>I appreciate the more efficient version, but I do not consider a
package like relude to be an alternative to base (due to
dependencies, maintenance).<br>
</p>
<div class="gmail-m_8354808836249172094gmail-m_-5193889276122435955moz-cite-prefix">On 5/8/19 10:50 PM, Dmitriy Kovanikov
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">I would like to add one more point of reference to
the discussion. The `foldMapA` function is also implemented in
the `relude` alternative prelude:
<div><br>
</div>
<div><a href="http://hackage.haskell.org/package/relude-0.5.0/docs/src/Relude.Foldable.Fold.html#foldMapA" target="_blank">http://hackage.haskell.org/package/relude-0.5.0/docs/src/Relude.Foldable.Fold.html#foldMapA</a><br>
</div>
<div><br>
</div>
<div>And the implementation already uses `Ap` and `getAp` as was
discussed here. Previous implementation used `fmap` and
`traverse` but it was changed to a more efficient one.</div>
<div><br>
</div>
<div>One possible improvement: instead of current implementation</div>
<div><br>
</div>
<div><span style="font-family:sans-serif">> foldMapA f =
getAp . foldMap (Ap . f)</span><br>
</div>
<div><span style="font-family:sans-serif"><br>
</span></div>
<div><span style="font-family:sans-serif">It can be slightly
more efficient (I guess) by using #. operator to coerce
newtypes</span></div>
<div><span style="font-family:sans-serif"><br>
</span></div>
<div><span style="font-family:sans-serif">> foldMapA f =
getAp #. foldMap (Ap . f)</span><span style="font-family:sans-serif"><br>
</span></div>
<div><span style="font-family:sans-serif"><br>
</span></div>
<div><span style="font-family:sans-serif">The implementation in
`relude` also contains recommended order of variables under
`forall`. After using `foldMapA` in production for a while
we've figured out in what order variables should go to
resolve most often ambiguities via TypeApplication.</span></div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Wed, May 8, 2019 at 12:36
PM David Feuer <<a href="mailto:david.feuer@gmail.com" target="_blank">david.feuer@gmail.com</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="auto">
<div>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Wed, May 8, 2019,
12:12 AM Bryan Richter <<a href="mailto:b@chreekat.net" target="_blank">b@chreekat.net</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="auto">
<div>Hi David,</div>
<div dir="auto"><br>
</div>
<div dir="auto">At the risk of invoking the gods of
Language Blorp, I will note that as a working
programmer I know exactly what Applicative,
Traversable, and Monoid are (from Vanessa's
original proposal), but the unfortunately-named
getAp is something I will only learn about
begrudgingly.</div>
</div>
</blockquote>
</div>
</div>
<div dir="auto"><br>
</div>
<div dir="auto">That seems unfortunate. Learning to use such
types is pretty useful. I'd recommend that every Haskell
programmer get to know all the types in Data.Monoid and
come to an understanding of what they're good for.</div>
<div dir="auto"><br>
</div>
<div dir="auto">
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="auto">
<div dir="auto"><br>
</div>
<div dir="auto">What you consider "so simple we
don't need to define it" took a rather lengthy
email to describe. Are you sure it's not worth
actually defining?</div>
</div>
</blockquote>
</div>
</div>
<div dir="auto"><br>
</div>
<div dir="auto">So ... that long post was about trying to
prove what I intuitively thought *must* be true. In the
end, I wasn't quite able to finish the proof, but I did at
least manage to convince myself that my intuition was
correct. It's true that this sort of intuition takes a
certain amount of time to develop. In the case of a really
important operation, yeah, we should package it up. But is
this operation important enough? I'm not really convinced
yet.</div>
<div dir="auto"><br>
</div>
<div dir="auto"><br>
</div>
<div dir="auto">
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="auto">
<div dir="auto"> If nothing else, the next time
someone searches Hoogle for a function matching
its type signature, perhaps it will be an
opportunity for someone like me to peer beneath
the hood and learn something new.</div>
</div>
</blockquote>
</div>
</div>
<div dir="auto"><br>
</div>
<div dir="auto">That's valid. But ... there are lots of
opportunities for that sort of thing already. Is it worth
the API clutter to add another one?</div>
</div>
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