On Saturday 06 October 2001 03:47 pm, Erik Lechak wrote:
> Thank you for the info. I am more engineer than computer scientist,
> so please excuse the ignorance behind these questions.
No problem.
>
> > Except that the operator truly is simply an underscore. But it's also a
> > valid identifier character, so where it may be confused with that, you
> > are simply required to make it less ambiguous to the parser.
> >
> > $a _= $b _ $c; # $a _= $b _$c;
> > ${a}_=${b}_$c;
> > %h{$s}_="Hello, "_"world!\n";
> >
> > As Larry said, no different that the other operators that also consist
> > of valid character identifiers.
>
> I understand that the operator is just the underscore. However, in the
> third edition of the camel book on page 49, the second paragraph, it
> states that "An identifier is a token that starts with a letter or
> underscore and contains only letters, digits, and underscores." Since
> there are no singel letter operators, no single digit operators, but now
> we see the advent of the underscore operator, it follows that the
> underscore will be the only operator that could be confused as part of the
> variable name.
'x' is a single letter operator.
>
> 1) My question is what other operator could be confused with an
> identifier?
Not including the list operators or control flow keywords:
eq, ne, gt, lt, ge, le, cmp, x, and, or, not, xor
$a = $bx4; # $a = "$b"x4; $a = $b x 4;
if ($one foo || $o nefoo) # if ("$o"ne foo); if ($o ne foo) ; if (${o}ne&foo)
etc...
>
> 2) Where did Larry say "no different that the other operators that also
> consist of valid character identifiers." ?
Hmm. It looks like he didn't. That must have been a point someone had made
in a subsequent posting. I apologize.
>
> > IIRC, '^' was considered earlier. (And it's shifted, BTW.)
>
> 3) What do you mean by shifted?
A caret on a standard US qwerty keyboard is "shift-6'. (In reponse to your
complaint (a), about the underscore requiring the shift key.)
--
Bryan C. Warnock
[EMAIL PROTECTED]
