Case insensitive comparison through Quality of Life method `String#=~(other : String)`

[Sija]

Feature Request

I propose adding a new QoL method String#=~(other : String) with the implementation like below:

class String
  def =~(other : String, *, options : Unicode::CaseOptions = :none) : Bool
    compare(other, case_insensitive: true, options: options).zero?
  end
end

This IMO supplements String#=~(regex : Regex).

[straight-shoota]

A short cut for case-insensitive comparison could be handy.

But there are some issues with =~: It's not explicit about its behaviour, and that can lead to misinterpretation.

From x =~ y, knowing both arguments are strings, it's far from obvious what the operator would mean.
For example, deriving from the behaviour of =~ with Regex ("a b c" =~ /b/ # => 2) could suggest semantics more similar to String#includes?.

x.compare(y, case_insensitive: false) is a lot more bulky, but that makes it explicit and thus it's very clear what it does.

[ysbaddaden]

I wish we had a case insensitive equality operator; #compare(case_insensitive: true) == 0 is painful; yet =~ already has too much meaning.

[Sija]

@ysbaddaden Yup, it was my wish as well, and the =~ operator was the closest (and only) one available. #compare has its counterpart in a form of <=> operator, whilst no such exist for case insensitive comparisons unfortunately.

[ysbaddaden]

Maybe just iequal?, #ieql?, #icompare, ... but now that I write them, they're too far from being descriptive.