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From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.lang.perl
Subject: Re: null? or not null?
Message-ID: <11124@jpl-devvax.JPL.NASA.GOV>
Date: 19 Jan 91 20:51:10 GMT
References: <YbZGbb600VpQ82Jl1T@andrew.cmu.edu>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 27

In article <YbZGbb600VpQ82Jl1T@andrew.cmu.edu> rm55+@andrew.cmu.edu (Rudolph T. Maceyko) writes:
: while (($a,$b) = (&function)[7,8]) {
: 
: My problem is that the condition is always true!
: ...
: So how do I do what I want to do without using "dummy" variables like
: this:
: 
: while (($x,$y,$z,$a,$b) = &function) {

There's More Than One Way To Do It:

    while (($a,$b) = grep(defined, (&function)[7,8]))

    while (($a,$b) = (&function)[7,8], defined $a)

    while (grep(defined, ($a,$b) = (&function)[7,8]))

    while (join(' ', ($a,$b) = (&function)[7,8]))

If $a will always be true on successful return:

    while (($a,$b) = (&function)[7,8], $a)

    while ((($a,$b) = (&function)[7,8])[0])

Larry