in reply to Re^4: Unmatched [ in regex; marked by <-- HERE in m/[ <-- HERE ^]/ (updated)
in thread Unmatched [ in regex; marked by <-- HERE in m/[ <-- HERE ^]/

> where it would otherwise put a sub call.

which isn't trivial within strings/regexes.

the "@{[...]}" trick works but is IMHO a bit oversized for this task.

  DB<109> use constant STR => 1..3

  DB<110> qr/[@{[ STR ]}]/
 => qr/[1 2 3]/

[download]

thats not interpolation anymore but inline eval.

Cheers Rolf

( addicted to the Perl Programming Language)

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Re^6: Unmatched [ in regex; marked by <-- HERE in m/[ <-- HERE ^]/
by AnomalousMonk (Archbishop) on Apr 30, 2014 at 11:07 UTC

    Here's another way, but I can't say it's any less klutzy. There seems to be no way to avoid the use of some kind of operator for disambiguation. 

    use warnings;
use strict;

use constant STR   => 'a string';
use constant STREF => \'ref to a string';

print qq{one way '${ \STR }' and another '${ +STREF   }' \n};
print qq{and with another disambiguation '${  STREF() }' \n};

    [download]

    Output: 

    c:\@Work\Perl\monks>perl constant_interpolation_1.pl
one way 'a string' and another 'ref to a string'
and with another disambiguation 'ref to a string'

    [download]

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