[ruby-core:65900] [ruby-trunk - Feature #10426] [Open] A predicate to express congruence

Issue #10426 has been reported by Tsuyoshi Sawada.

----------------------------------------
Feature #10426: A predicate to express congruence
https://bugs.ruby-lang.org/issues/10426

* Author: Tsuyoshi Sawada
* Status: Open
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
----------------------------------------
I occasionally felt the necessity of a predicate that checks congruence with respect to some operations:

~~~ruby
class Object
	def equal_by? other, &pr
		pr.call(self) == pr.call(other)
	end
	alias congruent? equal_by?
end

5.congruent?(2){|e| e % 3} #=> true
"HELLO".equal_by?("Hello", &:downcase) #=> true
~~~



-- 
https://bugs.ruby-lang.org/