From: "David A. Black" <dblack@...>
Date: 2004-08-07T01:32:31+09:00
Subject: Re: %w for symbols

Hi --

On Sat, 7 Aug 2004, Ara.T.Howard wrote:

> On Fri, 6 Aug 2004, David A. Black wrote:
> 
> > That actually points to another thing I was wondering about, namely,
> > what would be the %?{ } equivalent of:
> >
> >  ["abc".intern, "hi there".intern]
> >
> > You couldn't do (using %m as a placeholder here):
> >
> >  %m{abc hi there}
> >
> > It would have to be
> >
> >  %m{abc "hi there"}
> >
> > I'm just wondering whether that would lead down a path of escape syntax that
> > would make it less streamlined.
> 
> we are already down that path
> 
>    jib:~ > ruby -r yaml -e 'y %w(abc hi there)'
>    ---
>    - abc
>    - hi
>    - there
> 
> eg.  there is not %w equivalent of ["abc", "hi there"] and this has not been a
> problem.

OK... but that's not exactly the same as the question of the costs and
benefits of introducing a new %? construct.

> i don't think it would be a problem for symbols either since you could never
> really need to do
> 
>    obj.send 'hi there'.intern
> 
> since you could never define
> 
>    def hi there
>      42
>    end
> 
> and you could never need
> 
>    hash['hi there'.intern]
> 
> since you could not type
> 
>    hash[:hi there]

You could do it like this:

  irb(main):007:0> h = {}
  => {}
  irb(main):008:0> h["hi there".intern] = 1
  => 1
  irb(main):009:0> h[:"hi there"]
  => 1

(i.e., not being able to do [:hi there] doesn't rule this out)

> well, never is a strong word - but this issue seems even more unlikely to
> occur than needing to do it via a wordlist since symbols containing white
> space are far and few between.

Maybe, but people are always talking about using symbols to speed up
hashes, etc....  And symbols *can* act that way, so not accomodating
it in some way would be somewhat arbitrary.


David

-- 
David A. Black
dblack@wobblini.net