Re^3: regex issue

You would have to do it with eval:

use strict;
use warnings;

my $ref;
my ($A,$B);
while (<DATA>) {
  chomp;
  if (s/^\s+//) { eval "\$$ref = $_" }
  else {$ref = $_}
}
print "A=$A and B=$B\n";
__DATA__
A
 33
B
 22
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Comment on Re^3: regex issue Download Code

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Re: Re^3: regex issue by CountZero (Bishop) on Mar 24, 2004 at 22:04 UTC
No, no, that's cheating. You cannot predeclare `my ($A,$B)` as you are not supposed to know what's in the data-file. It could be any variable name and any value. However, the `eval` suggestion is a good one. How about: `$name ='A'; $value =10; $string = 'my $' . $name . '=' . $value . '; print "result inside eval +: $A\n";'; eval ($string) or die "ERROR: $@"; print "result outside eval: $A\n";` [download] As can be expected the lexical declaration does not survive outside of the eval though :-( CountZero "If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law	[reply] [d/l] [select]

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Re: Re^3: regex issue
by CountZero (Bishop) on Mar 24, 2004 at 22:04 UTC

You cannot predeclare my ($A,$B) as you are not supposed to know what's in the data-file. It could be any variable name and any value.

However, the eval suggestion is a good one. How about:

$name ='A';
$value =10;
$string = 'my $' . $name . '=' . $value . '; print "result inside eval
+: $A\n";';
eval ($string) or die "ERROR: $@";
print "result outside eval: $A\n";
[download]

As can be expected the lexical declaration does not survive outside of the eval though :-(

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

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