Legal variable names

On Wed, 22 Nov 2000, Stanislav Malyshev wrote:

> AL>> you don't hinder me doing ${' asdf asdlkfj'}=5; so why should you strip
> AL>> leading spaces?
>
> That's what I was asking. I just am rather careful there because somebody
> wrote that code so he should have meant something by it - maybe there are
> reasons I'm not aware of.

    With regard to php-lang, are there any opinions on whether
    a construct like this should be legal?

        '${' expression '}'

    where expression evaluates to an arbitrary string, not
    necessarily to an identifier (which is basically
    [a-z][a-z0-9]*).

    - Sascha