From: "Shot (Piotr Szotkowski)" <shot@...>
Date: 2009-06-12T03:25:56+09:00
Subject: Re: Idiomatic way to detect first/last iteration?

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Kendall Gifford:

> Hi there, is there any recognized ruby idiomatic way for detecting
> when you're on the first and/or last iteration over a collection? [=E2=80=
=A6]

> genres =3D %w{ classical punk rock jazz }
> genres.each_with_index do |genre, i|
>   desc =3D "one of my favorites"
>   desc =3D "my absolute favorite" if i.zero?
>   desc =3D "my least fav. of all my favorites" if i + 1 =3D=3D genres.len=
gth
>   puts "#{genre} is #{desc}"
> end

In general, #equal? should check object identity:

genres =3D %w{ classical punk rock jazz }
genres.each do |genre|
  case
  when genre.equal?(genres.first) then puts "#{genre} is my absolute favori=
te"
  when genre.equal?(genres.last)  then puts "#{genre} is my least fav. of a=
ll my favorites"
  else                                 puts "#{genre} is one of my favorite=
s"
  end
end

=E2=80=94 Shot
--=20
Wife likes =E2=80=98Go Diego Go=E2=80=99 because =E2=80=98it teaches the bo=
ys Spanish=E2=80=99. That shit
teaches you Spanish like porn teaches you social skills.   [Mark Pilgrim]

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