On Jul 10, 10:28 am, James Edward Gray II <j... / grayproductions.net>
wrote:
> On Jul 10, 2007, at 9:24 AM, Paul Battley wrote:
>
> > On 10/07/07, James Edward Gray II <j... / grayproductions.net> wrote:
> >> I've also recently adopted the trick of using _ as an unused
> >> parameter name.  I believe it was Ara that first suggested this and I
> >> think it's a great idea:
>
> >>    hash.sort_by { |key, _| ... }...
>
> > I thought it came from Haskell, where _ is a wildcard parameter:
>
> I meant that I believe it was Ara who recommended it as a good name
> for an unused block parameter in Ruby.
>
> James Edward Gray II

Just as an aside, I believe Erlang adopts this style as a part of this
language, where it will warn if you have unused variables but allows
you to annotate them with _ (ex. _var) to denote that they will not be
used, or just replace the variable name with _ thus eliminating the
warning.

(I don't know Erlang yet, just remembered reading this in
http://pragdave.pragprog.com/pragdave/2007/04/a_first_erlang_.html)