From: sawadatsuyoshi@...
Date: 2014-10-26T00:38:59+00:00
Subject: [ruby-core:65898] [ruby-trunk - Feature #10425] [Open] A predicate method to tell if a number is near another

Issue #10425 has been reported by Tsuyoshi Sawada.

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Feature #10425: A predicate method to tell if a number is near another
https://bugs.ruby-lang.org/issues/10425

* Author: Tsuyoshi Sawada
* Status: Open
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
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A method `near?` like the following would be useful.

~~~ruby
class Numeric
	def near? other, delta: Float::EPSILON
		(other.to_f - to_f).abs <= delta.to_f
	end
end

class Time
	def near? other, delta: Float::EPSILON
		to_f.near?(other.to_f, delta: delta)
	end
end
~~~

It can be used to check errors, or whether something is around something.

~~~ruby
23.24324.near?(23.23, delta: 0.5) # => true
t1 = t2 = Time.now
t3 = Time.now
t1.near?(t2) #=> true
t1.near?(t3) #=> false
5.near?(3, delta: 1) #=> true
~~~

Some testing frameworks have something similar to this, but I think this is an elementary concept that Ruby should support at it core.




-- 
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