From: ahoward <ahoward@...>
Date: 2003-06-18T03:06:24+09:00
Subject: Re: [RCR] Array#push(empty array expanded) => no exception

On Tue, 17 Jun 2003, Simon Strandgaard wrote:

> This strange behavier really surprised me..
>
> irb(main):006:0> [].push(*[])
> ArgumentError: wrong number arguments (at least 1)
>         from (irb):6:in `push'
>         from (irb):6
>
>
> Why is it illigal to concatenate an empty set ?
> I expected Rubys Array class to work just like a normal set.
> This seems *VERY* non-intuitive to me (POLS).
>
> Array#unshift doesn't like zero arguments neither.
>
>
> An ugly hack to avoid it could be:
>    @data.unshift(*objs) unless objs.empty?
>
>
>
> Can it be made legal to push/unshift with zero arguments ?

and what would it do?  create a stack frame, and then return?  to call a
function which does nothing is much more an expense than simply doing

  [].push *[] unless [].empty?
  [].unshift *[] unless [].empty?

or even

  [].push *[] rescue nil
  [].unshift *[] rescue nil

i think under normal conditions people would consider it an error to call a
method which becomes a no-op, without so much as a warning, when called with
no arguments.  *that* would violate my POLS.

my 2 cents.


-a
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