Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!hp4nl!mhres!squirrel!pronto!jv
From: jv@mh.nl (Johan Vromans)
Newsgroups: comp.lang.perl
Subject: Re: alpha numbers
Message-ID: <1991Jun25.134732.1668@pronto.mh.nl>
Date: 25 Jun 91 13:47:32 GMT
References: <1991Jun23.200134.18835@pronto.mh.nl>
	<1991Jun24.231628.14446@jpl-devvax.jpl.nasa.gov>
Sender: jv@pronto.mh.nl (Johan Vromans)
Reply-To: Johan Vromans <jv@mh.nl>
Organization: Multihouse Automation, the Netherlands
Lines: 49
In-Reply-To: lwall@jpl-devvax.jpl.nasa.gov's message of 24 Jun 91 23:16:28 GMT
X-Md4-Signature: 3ae076a4284dcf2602e23534433d72fd


(Tom Christiansen) writes:
| (Johan Vromans) writes:
| ::
| ::	$a = "1a";
| ::	$a++;
| ::
| ::IMHO, the correct value for $a should now be "1b", not 2.
| 
| Silly me -- as I was gently reminded in mail,  the regexp for 
| string magic is documented in the man page to be:
| 
|     /^[a-zA-Z]*[0-9]*$/

I know. That's why I wrote 'IMHO'.

(Larry Wall) writes:

| Would you have expected an error for this?
| 
| 	$a = "1\n";
| 	$b = $a + 1;

Why not? (See below.)

| There are many times when you want it to ignore the rest of the string just
| like atof() does.  Oddly enough, Perl calls atof().  How convenient.  :-)

This is debatable. Since perl's nature is forgiving, I can live with
its current behaviour. However, if the '-w' option is used, I'd like
to have a warning issued.

| Okay, tell me the correct value for this:
| 
| 	$a = "1e0";
| 	$a++;

If $a is a valid number, use aritmetic. Otherwise, treat it as a string
and use magical increment. You might limit validity to /\w+/.
In all cases, issue a warning when '-w' is used and the syntax of the
argument is not OK.

	Johan

-- 
Johan Vromans				       jv@mh.nl via internet backbones
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