Proposal and discussion: Deprecate Data.Set.mapMonotonic and Data.Map.mapKeysMonotonic; add correctly named functions

[Andreas Abel]

+1  That would be consistent ;)  (in some sense at least).

On 12.07.2016 07:49, David Feuer wrote:
> Fine. Sounds like I lose this one. Should the duals be mapAntitone and
> mapKeysAntitone?
>
> On Jul 12, 2016 1:44 AM, "Edward Kmett" <ekmett at gmail.com
> <mailto:ekmett at gmail.com>> wrote:
>
>     I'm also slightly biased against renaming, as the intent is signaled
>     pretty clearly.
>
>     -Edward
>
>     On Mon, Jul 11, 2016 at 6:12 AM, Andreas Abel <abela at chalmers.se
>     <mailto:abela at chalmers.se>> wrote:
>
>         I thought the current functions are quite clear with a bit of
>         common sense.  They assume the renaming of keys does not change
>         their relative order, so the underlying tree structure of the
>         map/set can remain as-is.
>
>         Of course, as you point out, the names are not precise, but
>         cannot the documentation add what is not reflected in the names?
>
>         The question is, as always, if the breakage caused by the
>         renaming compensates for having the optimal name.  I am slightly
>         biased against the renaming.
>
>         --Andreas
>
>
>         On 09.07.2016 02:28, David Feuer wrote:
>
>
>             On Jul 8, 2016 7:18 PM, "Ivan Lazar Miljenovic"
>             <ivan.miljenovic at gmail.com
>             <mailto:ivan.miljenovic at gmail.com>
>             <mailto:ivan.miljenovic at gmail.com
>             <mailto:ivan.miljenovic at gmail.com>>> wrote:
>               >
>               > On 9 July 2016 at 03:49, David Feuer
>             <david.feuer at gmail.com <mailto:david.feuer at gmail.com>
>             <mailto:david.feuer at gmail.com
>             <mailto:david.feuer at gmail.com>>> wrote:
>
>               > > Data.Set: mapStrictlyIncreasing and mapStrictlyDecreasing
>               > > Data.Map: mapKeysStrictlyIncreasing and
>             mapKeysStrictlyDecreasing
>               >
>               > With the latter function also flipping the underlying
>             tree structure?
>
>             I'm not quite sure what you mean, but I think the answer is yes.
>
>             mapKeysStrictlyDecreasing (\x -> -x) (fromList [1..10]) ===
>             fromList
>             [(-10) .. (-1)]
>
>               >
>               > > Data.Map presents another possibility, however. We
>             could make the
>               > > replacements more general, giving them types
>               > >
>               > > Ord k => (k -> v -> (k', v')) -> Map k v -> Map k' v'
>               > >
>               > > and allowing the user to map over both keys and values
>             in one pass.
>               >
>               > Though IIUC this provides no way of specifying that "I'm
>             sure this
>               > function has a 1-1 monotonic relationship so you can
>             just update the
>               > keys without changing the structure" (in the sense of
>             there's no way
>               > to distinguish between the increasing and decreasing sense).
>
>             That is the pre-condition. There still needs to be one for
>             strictly
>             increasing functions and another for strictly decreasing
>             ones, since
>             they lead to reversed tree structures.
>
>               >
>               > Overall, I'm about +0.5 from the naming sense of the current
>               > functions, but have used these in the past.
>
>             I don't understand this statement.
>
>
>
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>
>
>         --
>         Andreas Abel  <><      Du bist der geliebte Mensch.
>
>         Department of Computer Science and Engineering
>         Chalmers and Gothenburg University, Sweden
>
>         andreas.abel at gu.se <mailto:andreas.abel at gu.se>
>         http://www2.tcs.ifi.lmu.de/~abel/
>
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>

-- 
Andreas Abel  <><      Du bist der geliebte Mensch.

Department of Computer Science and Engineering
Chalmers and Gothenburg University, Sweden

andreas.abel at gu.se
http://www2.tcs.ifi.lmu.de/~abel/