3 ms·
No it doesn't have the same flexibility. Perl 6's string quoting sub language has various feature flags that you can turn on or off. Here are a few of the bas
by b2gills 9y ago
No it doesn't have the same flexibility.
Perl 6's string quoting sub language has various feature flags that you can turn on or off.
Here are a few of the basic ones shown in valid code (comments and newlines included)
# start quoting with no features enabled
# (not even backslashing the delimiter is enabled)
Q
:scalar # enable $foo
:array # enable @foo[]
:hash # enable %foo{}
:closure # enable { 12/3 }
:function # enable &foo('bar')
:single # turns on backslashing the delimiter
:backslash # enable \n
:!exec # turn off executing it (redundant)
:exec(0) # another syntax for turning off a feature
{…} # various delimiters are allowed (generally punctuation)
There are shorter variants of each of the feature flags. :c => :closure
I would like to point out that the parsing of the :closure and :function part of the sub language is reentrant. (Actually most of them add some form of reentrancy, it is just harder to show it for the others)
"a b &foo( "c d &bar( "baz" )" )"
Note that this reuses the base Perl 6 parser, and that is why it is reentrant.
There are shortcuts for regularly used forms
｢｣ =:= Q[]
'' =:= q[] =:= Q:q[] =:= Q:single[]
"" =:= qq[] =:= Q:qq[] =:= Q:double[]
=:= Q:b:s:a:h:c:f[]
=:= Q:backslash:scalar:array:hash:closure:function[]
The ability to turn off features can be useful
qq :!c [a {\n b\n} c] # { and } don't form a closure here
I would like to point out that the :foo syntax is used everywhere in the language for named parameters to routines and operators (most operators are implemented as subroutines)
:foo =:= :foo( True ) =:= foo => True
:!bar =:= :bar( False ) =:= bar => False
:$baz =:= :baz( $baz ) =:= baz => $baz
If the delimiters are paired () <> {} ｢｣ «» “” ‘’ you can double up on them.
q<FOO> =:= q<<FOO>> =:= q<<<<<FOO>>>>>
This is useful to avoid having to backslash a delimiter within the string, or trying to find a delimiter that isn't in the string.
q<< <a> >> =:= q' <a> '