Feature #12734: `Array#flat?`

• Status: Closed
• Assignee: -
• Target version: -

[sos4nt (Stefan Schüßler)]

It might be useful to have a method that determines whether an array is flat, i.e. one-dimensional.

[1, 2, 3].flat?   #=> true
[1, [2, 3]].flat? #=> false

The result should be equivalent to ary == ary.flatten (without the overhead of actually flattening the array)

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Feedback

Please explain the use-case.
It doesn't seem useful to me.

[herwin (Herwin W)]

This is pretty trivial to implement yourself:

class Array
  def flat?
    none?{|e|e.is_a?(Array)}
  end
end
[1,2,3].flat?
=> true
[1,[2,3]].flat?
=> false

I have to agree with Nobuyoshi Nakada that I don't really see the use case here.

[sos4nt (Stefan Schüßler)]

Herwin W wrote:

This is pretty trivial to implement yourself:

Oh, you're right. I didn't realize that this is merely a type check.

May someone close this feature request?

[shyouhei (Shyouhei Urabe)]

• Status changed from Feedback to Closed

OK, closing as per request.