From: quixoticsycophant@... (Jeff Mitchell)
Date: 2003-09-08T01:36:06+09:00
Subject: Re: proposal for a named parameter prefix

nobu.nokada@softhome.net wrote in message news:<200309071005.h87A5o4D004546@sharui.nakada.kanuma.tochigi.jp>...
> Hi,
> 
> At Sun, 7 Sep 2003 04:13:18 +0900,
> Jeff Mitchell wrote:
> > I propose:
> > 
> > def foo4(*array,%params,&block)
> >   array.each do |a|
> >     # ...
> >   end
> >   params.each do |key, value|
> >     # ...
> >   end
> >   @callback = block
> > end
> > 
> > from above,
> > 
> > def foo3(%what_is_this)
> >   # ...
> > end
> > 
> > Aha there's a percent sign so we know it's a hash.
> 
> Why does a percent sign mean a hash?

Because it was the arbitrary character I chose in the proposal above.

Also, "coincidentally", it happens to be perl's sigil for hash (just like
"&" happens to be perl's sigil for code block).

It doesn't have to be a hash per se, just "the thing that holds named
parameters".

> 
> > To summerize, "%" gets us two things
> > 
> >   (1) a nice signal to let everyone know a named parameter hash is
> >       there
> > 
> >   (2) the ability to mix variable-length arguments with named
> >       parameters (in a nice way)
> 
> IIRC, matz has thought ** for it.

Hm?  My first reaction is that it would be confusing since ** suggests
"splat twice" (whatever that means).
--
Jeff