$'name

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

If the $' in $'var is not at all related to $', how does Perl keep them straight?
ex:

#!/usr/bin/perl -wl
use strict;

$main::var       =  "a rose by ";         #$main::var
$main'var        =  $'var."another name"; #$main::var again

use vars q($var);
$var             =~ s/(\b\w)/uc($1)/ge;  #$main::var 
$var             =~ /N/;
print $'var;                              #print $main::var

print 'G'.$'." With $'var";               #games with $'

use English;
print "s$' and s$POSTMATCH";
[download]

mkmcconn

Comment on $'name Select or Download Code

Replies are listed 'Best First'.
(tye)Re: $'name by tye (Sage) on Mar 01, 2001 at 01:43 UTC
See line 5811 of toke.c (for Perl5.6.0): `else if (*s == '\'' && isIDFIRST_lazy_if(s+1,UTF)) {` [download] So, in effect, `/\$'[a-zA-Z_]/` is treated differently than `/\$'[^a-zA-Z_]/` [note the caret (^)]. - tye (but my friends call me "Tye")	[reply] [d/l] [select]
The $'name G'ame. by tadman (Prior) on Mar 01, 2001 at 01:18 UTC
I would suppose that the lexer in the perl parser is intelligent enough to recognize the pattern for variables of that sort. It could loosely be described as: `\$'([a-zA-Z_][a-zA-Z0-9_]*)?` Which could define a valid variable name. Otherwise, how would you distinguish between $x and $xy? Or, $_ and $_x for that matter.	[reply] [d/l]

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