Multiple variable assignments with RexExp

blackjudas has asked for the wisdom of the Perl Monks concerning the following question:

I'm sure this can be done, it just escapes me what the exact syntax is. I would like to modify a set of variables by one regex command. How can I do this? I've seen it done with a shortcut for plain assignment:

$var1 = $var2 = $var3 = 0;
[download]

How can this be done for the following with regex search/replace?

$var1 =~ $var2 =~ s/\n/<br>/g;
[download]

Thank ya!

blackjudas

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Re: Multiple variable assignments with RexExp by FoxtrotUniform (Prior) on May 21, 2002 at 20:29 UTC
I've never seen it done that way. My approach would be a bit more idiomatic and (probably) easier to read, but the mechanism's a tiny bit obscure: `s/\n/<br>/g foreach ($var1, $var2);` [download] `-- :wq`	[reply] [d/l]
Re: Multiple variable assignments with RexExp by particle (Vicar) on May 21, 2002 at 20:56 UTC
perl 6 hyper-operator, anyone? `($var1, $var2) ^=~ s/\n/<br>/g;` [download] i think this will be the idiom in the near future. i can't wait! ~Particle jonesin' for perl 6	[reply] [d/l]
Re: Multiple variable assignments with RexExp by Zaxo (Archbishop) on May 22, 2002 at 03:58 UTC
Here's a somewhat heretical solution: `map {s/\n/<br\/>/g} $var1, $var2;` [download] Yes, map in void context. It is acting as an operator, modifying its arguments as do chomp, splice, and others. The substution acts on $_ which is, in map's codeblock, an alias to the current list argument This won't work for constant arguments, of course. Go ahead and assign from it if you need statistics on the number of substitutions. The style campaign against map in void context makes the device all the more helpful at calling attention to using map for side effects. After Compline, Zaxo	[reply] [d/l]
Re: Re: Multiple variable assignments with RexExp by rob_au (Abbot) on May 22, 2002 at 05:23 UTC
Map in a void context! Bad Zaxo! :-) I cannot fathom why you would take this approach when the following would be much clearer and avoid the building of a list return which is being discarded: `s/\n/<br\/>/g for $var1, $var2;` [download] Note too, that this isn't a "style" issue, but one of using the best function for a given task - Yes, `map` does fit the task here, however it is only the loop function of `map` which you are making use of, not the list return, a function better suited to a `for` or `foreach` loop.	[reply] [d/l] [select]