use strict;
my $str = 'type == \'prova\' && padposition == "stefano" or 10>var_name';
my $regex = qr~# you define first the basic elements (as for a lexer) with named groups
(?(DEFINE)
(?<var> [a-z_]\w*)
(?<dqstr> (?<=") [^\\"]*+ (?s:\\.[^\\"]*)*+ (?=") )
(?<sqstr> (?<=') [^\\']*+ (?s:\\.[^\\']*)*+ (?=') )
(?<string> \g<dqstr> | \g<sqstr> )
(?<num> [0-9]+(?:\.[0-9]+)? )
(?<value> \g<string> | \g<num> )
(?<comp> [!><=]= | =?[><])
)
# Then you write the pattern using these named groups
(?J) # allow duplicate named groups
# variable op value
(?<key> \g<var> ) \h* \g<comp> \h* ["']?(?<val> \g<value>) ["']?
| # OR
# value op variable
["']?(?<val> \g<value>) ["']? \h* \g<comp> \h* (?<key> \g<var> )
~xip;
if ( $str =~ /$regex/g ) {
print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n";
# print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n";
# print "Capture Group 2 is $2 ... and so on\n";
}
# ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p'
# Named capture groups can be called via $+{name}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html