Issue #13784 has been updated by davidarnold (David Arnold).


> I decided to update the pull request so that 'filter' and 'filter!' would work like 'select' and 'select!' for Array, Hash, Set, SortedSet, and ENV. I added spec and tests for filter to each of these, and given find_all's strange lack of testing or documentation, basing it on select seemed like the best course of action.

Awesome!  Thank you.  I am beginning to get a little suspicious that find_all keeps getting left behind because almost no one uses that name.  I personally haven't seen any books or online examples where someone favored find_all over select.

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Feature #13784: Add Enumerable#filter as an alias of Enumerable#select
https://bugs.ruby-lang.org/issues/13784#change-66105

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

For example, Swift, Python, and ECMAScript all use the names map, filter, and reduce to describe these methods.  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.  This feature request is simply to add an alias to Enumerable for filter.  This will ease the transition of developers from other languages to Ruby.

Desired behavior:

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

Current behavior:

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



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