/ 
Quote-Code-1.01
River stage one • 2 direct dependents • 6 total dependents
/ Quote::Code

NAME

Quote::Code - quoted strings with arbitrary code interpolation

SYNOPSIS

use Quote::Code;
print qc"2 + 2 = {2 + 2}";  # "2 + 2 is 4"
my $msg = qc{The {$obj->name()} is {$obj->state()}.};

my $heredoc = qc_to <<'EOT';
.trigger:hover .message:after {
  content: "The #{get_adjective()} brown fox #{get_verb()} over the lazy dog.";
}
EOT
print $heredoc;

my $name = "A B C";
my @words = qcw(
  foo
  bar\ baz
  {2 + 2}
  ({$name})
);
# @words = ("foo", "bar baz", "4", "(A B C)");

DESCRIPTION

This module provides the new keywords qc, qc_to and qcw.

qc

qc is a quoting operator like q or qq. It works like q in that it doesn't interpolate $foo or @foo, but like qq in that it recognizes backslash escapes such as \n, \xff, \N{EURO SIGN}, etc.

What it adds is the ability to embed arbitrary expressions in braces ({...}). This is both more readable and more efficient than the old "foo @{[bar]}" trick. All embedded code runs in scalar context.

If you need a literal { in a qc string, you can escape it with a backslash (\{) or interpolate code that yields a left brace ({'{'}).

qc_to

For longer strings you can use qc_to, which provides a heredoc-like syntax. The main difference between qc and qc_to is that qc_to uses the Ruby-like #{ ... } to interpolate code (not { ... }). This is because { } are more common in longer texts and escaping them gets annoying.

qc_to has two syntactic forms:

qc_to <<'FOO'
...
FOO

and

qc_to <<"FOO"
...
FOO

After qc_to there must always be a << (this is to give syntax highlighters a chance to get things right). After that, there are two possibilities:

  • An identifier in single quotes. Backslash isn't treated specially in the string. To embed a literal #{, you need to write #{'#{'}.

  • An identifier in double quotes. Backslash escapes are recognized. You can escape #{ by writing either \#{ or #\{.

Variables aren't interpolated in either case.

qcw

qcw is analogous to qw. It quotes a list of strings with code interpolation ({ ... }) like qc.

Differences between qcw and qw:

  • { ... } sequences are interpreted as expressions to be interpolated in the current word. The result of { ... } is not scanned for spaces or split.

  • Backslash escape sequences such as \n, \xff, \cA etc. are recognized.

  • Spaces can be escaped with a backslash to prevent word splitting: qcw(a b\ c d) is equivalent to ('a', 'b c', 'd').

AUTHOR

Lukas Mai, <l.mai at web.de>

COPYRIGHT & LICENSE

Copyright 2012-2013 Lukas Mai.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.