I think if select and filter are aliases on Enumerab= le they should also be aliases on Hash. I think it could be quite confusing= and almost seems like it violates some rule to override a method but not r= e-alias in the child class to the overriddden method unless there's a v= ery specific reason why.=C2=A0

On = Tue, Aug 8, 2017 at 17:35 <adp90@case.= edu> wrote:

Issue #13784 has= been updated by adp90 (Alexander Patrick).

A potential concern could be language bloat. Having too many aliases for th= e same methods could be confusing.
I was curious which underlying methods have the most aliases, so I wrote a = quick script to look through the code.

[C method name, number of aliases]
-------------------
["lazy_super", 5]
["rb_hash_has_key", 4]
["proc_call", 4]
["wmap_has_key", 3]
["time_utc_offset", 3]

All other methods have 1 or 2 aliases. Furthermore, lazy_super (chunk and s= lice methods) and proc_call aliases each do different things so they don= 9;t really count.

Filter would be enum_find_all's third alias. That could be fine, but I&= #39;m interested in others' thoughts on this.

On another note, there is a small difference between 'find_all' and= 'select', due to 'select' being overridden for hashes. (https://stackoverflo= w.com/questions/20999192/is-find-all-and-select-the-same-thing)
It might be inconsequential, but the 'filter' method in my pull req= uest acts more like 'find_all'.

hash =3D {a: 1, b: 2, c: 3, d: 4, e: 5, f: 6}

hash.select { |k,v| v.even? }
=3D> {:b=3D>2, :d=3D>4, :f=3D>6}

hash.find_all { |k,v| v.even? }
=3D> [[:b, 2], [:d, 4], [:f, 6]]

hash.filter { |k,v| v.even? }
=3D> [[:b, 2], [:d, 4], [:f, 6]]

----------------------------------------
Feature #13784: Add Enumerable#filter as an alias of Enumerable#select
https://bugs.ruby-lang.org/issues/13784#change-6= 6072

* Author: davidarnold (David Arnold)
* Status: Open
* Priority: Normal
* Assignee:
* Target version:
----------------------------------------
Ruby has a full set of functional tools in the Enumerable module under the = "-ect" methods (viz. collect, select, inject).=C2=A0 However the = usual industry terms for these are map, filter, and reduce.

For example, Swift, Python, and ECMAScript all use the names map, filter, a= nd reduce to describe these methods.=C2=A0 Also, this language independent = MIT course uses map, filter and reduce: http://web.mit.edu/6.005/www/fa15/classes/25-map-filter-reduce/

Ruby has aliases for map and reduce, but filter is noticeably absent.=C2=A0= This feature request is simply to add an alias to Enumerable for filter.= =C2=A0 This will ease the transition of developers from other languages to = Ruby.

Desired behavior:

[:foo, :bar].filter { |x| x =3D=3D :foo } # =3D> [:foo]

Current behavior:

[:foo, :bar].filter { |x| x =3D=3D :foo } # NoMethodError: undefined method= `filter'

--
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