variable $/
Documentation for variable $/ assembled from the following types:
language documentation Variables
From Variables
(Variables) variable $/
$/ is the match variable. It stores the result of the last Regex match and so usually contains objects of type Match.
'abc 12' ~~ /\w+/; # sets $/ to a Match object say $/.Str; # OUTPUT: «abc»
The Grammar.parse method also sets the caller's $/ to the resulting Match object. For the following code:
use XML::Grammar; # zef install XML
XML::Grammar.parse("<p>some text</p>");
say $/;
# OUTPUT: «「<p>some text</p>」
# root => 「<p>some text</p>」
# name => 「p」
# child => 「some text」
# text => 「some text」
# textnode => 「some text」
# element => 「<p>some text</p>」
# name => 「p」
# child => 「some text」
# text => 「some text」
# textnode => 「some text」»
Prior to the 6.d version, you could use $() shortcut to get the ast value from $/ Match if that value is truthy, or the stringification of the Match object otherwise.
'test' ~~ /.../; # 6.c language only: say $(); # OUTPUT: «tes»; $/.make: 'McTesty'; say $(); # OUTPUT: «McTesty»;
This (non-)feature has been deprecated as of version 6.d.
Positional attributes
$/ can have positional attributes if the Regex had capture-groups in it, which are just formed with parentheses.
'abbbbbcdddddeffg' ~~ / a (b+) c (d+ef+) g /; say $/[0]; # OUTPUT: «「bbbbb」» say $/[1]; # OUTPUT: «「dddddeff」»
These can also be accessed by the shortcuts $0, $1, $2, etc.
say $0; # OUTPUT: «「bbbbb」» say $1; # OUTPUT: «「dddddeff」»
To get all of the positional attributes, you can use $/.list or @$/. Before 6.d, you can also use the @() shortcut (no spaces inside the parentheses).
say @$/.join; # OUTPUT: «bbbbbdddddeff» # 6.c language only: say @().join; # OUTPUT: «bbbbbdddddeff»
This magic behavior of @() has been deprecated as of 6.d
Named attributes
$/ can have named attributes if the Regex had named capture-groups in it, or if the Regex called out to another Regex.
'I... see?' ~~ / \w+ $<punctuation>=[ <-[\w\s]>+ ] \s* $<final-word> = [ \w+ . ] /; say $/<punctuation>; # OUTPUT: «「....」» say $/<final-word>; # OUTPUT: «「see?」»
These can also be accessed by the shortcut $<named>.
say $<punctuation>; # OUTPUT: «「....」» say $<final-word>; # OUTPUT: «「see?」»
To get all of the named attributes, you can use $/.hash or %$/. Before 6.d language, you could also use the %() shortcut (no spaces inside the parentheses).
say %$/.join; # OUTPUT: «"punctuation ....final-word see?"» # 6.c language only say %().join; # OUTPUT: «"punctuation ....final-word see?"»
This behavior has been deprecated as of the 6.d version.