Map with a different Monoid instance

[Michael Snoyman]

That's a really good question, and could theoretically even generalize more
than that: should `insert` have a `Monoid` or `Semigroup` constraint on the
key as well? Should this API explicitly avoid any form of throwing away
values, and insist that, if that's the behavior you want, you do something
like `insertWith const`?

I think my guess is in line with yours, that the rest of the API functions
should continue with the discard behavior of the current API, but it's
worth at least raising the question.

On Thu, May 25, 2017 at 2:08 PM, David Feuer <david.feuer at gmail.com> wrote:

> Unbiased sounds nice, but I'm a bit concerned that it might suggest
> bigger differences than just the Monoid instance. I assume people
> still want the same left-biased union function.
>
> On Thu, May 25, 2017 at 3:43 PM, Michael Snoyman <michael at snoyman.com>
> wrote:
> >
> >
> > On Thu, May 25, 2017 at 11:38 AM, Mario Blažević <mblazevic at stilo.com>
> > wrote:
> >>
> >> On 2017-05-25 12:55 PM, David Feuer wrote:
> >>>
> >>> A lot of people have wrappers around Data.Map and Data.IntMap to give
> >>> them more useful (Semigroup and) Monoid instances. I'd like to add such
> >>> wrappers to containers. What we need to be able to do that are *names*
> for
> >>> the new modules. I can't think of any, so I'm reaching out to the list.
> >>> Please suggest names!
> >>
> >>
> >> Data.Map.Monoidal is not strictly correct but would give a pretty good
> >> idea at first glance.
> >>
> >> Data.Map.Symmetric would be more correct, since its Semigroup and Monoid
> >> instances would be symmetric, with no preference for the left argument
> as
> >> currently.
> >>
> >>
> >
> > Just to throw out an option here: Unbiased. I don't feel strongly about
> it,
> > but thought throwing it out may be helpful.
> >
> >>>
> >>> Another question is whether we should take the opportunity of new
> modules
> >>> to modernize and streamline the API a bit. I'd like, at least, to
> separate
> >>> "safe" from "unsafe" functions, putting the unsafe ones in .Unsafe
> modules.
> >>
> >>
> >>         I think it would be better to keep the API exactly the same,
> much
> >> like Data.Map.Strict does. I don't want to think about the incidental
> API
> >> differences when I switch from one module to another. If you're going to
> >> modernize, modernize all the modules at once. That's what version
> numbers
> >> are for.
> >
> >
> > +1. I'd also argue against changing the API right now.
> >
> > Michael
> >
> > _______________________________________________
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> >
>
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