From: Luigi Ballabio <luigi.ballabio@...>
Date: 2001-04-10T16:08:27+09:00
Subject: [ruby-talk:13593] Re: All In A Row?

At 12:40 PM 4/10/01 +0900, you wrote:
>I thought I saw something like this in my early readings on Ruby, but I
>cannot find it now.
>
>Is there a Ruby method for arrays that will determine if all of the elements
>are in a sequence?

Not that I know, but you can easily add it.

>Something like:
>
>[1, 2, 3, 4].sequence? -> true
>[1, 3, 4, 5].sequence? -> false
>
>["a", "b", "c", "d"].sequence? -> true
>["a", "c", "d", "e"].sequence? -> false

This can be quickly done with ranges, i.e.,

class Array
   def sequence?
     self == (self[0]..self[-1]).to_a
   end
end

>Maybe extrapolated to take an argument:
>
>[1, 3, 5, 7].sequence?(2) -> true
>[1, 5, 7, 9].sequence?(2) -> false
>
>["a", "c", "e", "g"].sequence?(2) -> true
>["a", "e", "g", "i"].sequence?(2) -> false

This needs just a bit more coding, but you should find it easy enough.

Bye,
         Luigi