Feature #17140: Merge Enumerable#grep(_v) with Enumerable#select/reject

• Status: Open
• Assignee: -
• Target version: -

[baweaver (Brandon Weaver)]

In recent versions of Ruby we've gotten new behavior of some Enumerable methods like any?, all?, none?, one?, and others to support a single argument pattern that responds to ===. This is very powerful, and very useful.

Currently Enumerable has grep and grep_v which allow this as a way to filter lists.

These names require some understanding of Unix to be familiar with, but naming aside, I feel it may make sense to implement === pattern arguments in Enumerable#select and Enumerable#reject as with the above.

Proposed Syntax:

list_of_numbers.select(1..10)
words.reject({ 'and', 'the', 'of' })

I believe this would help with readability and would simplify syntax options by unifying on this standard.

My concern is that Enumerable#find already takes a single argument, ifnone, and may not be able to implement this behavior. I would be curious to see how many use ifnone but feel this would be more critically breaking to do.

[duerst (Martin Dürst)]

I guess I understand the first example. Just to make sure:

[-3, 4, 0, 8.5, 20, 5].select(1..10) #=> [4, 8.5, 5]

But for the second example, I don't understand { 'and', 'the', 'of' }. Is that supposed to be an array, or what?

[marcandre (Marc-Andre Lafortune)]

I imagine that Set['and', 'the', 'of'] was meant.

[matz (Yukihiro Matsumoto)]

Enhancing select and reject seems a good idea.

Matz.

[nobu (Nobuyoshi Nakada)]

I made select parts.
https://github.com/nobu/ruby/pull/new/feature/17140-enum_select

[baweaver (Brandon Weaver)]

Would this feature still be of interest?