#!/usr/bin/perl -w
use strict;
use Text::Balanced qw(extract_codeblock);
for (
	'{ $h{x}  = "}" }',
	'{ $h{s}  = "}" }',
	'{ $h{s}  = 1; print "{oops}" }',
	'{ $h{m}  = "}" }',
	'{ $h{y}  = "}" }',
	'{ $h{tr} = "}" }',
	'{ $h{qq} = "}" }',
	'{ $h{qr} = "}" }',
	'{ $h{qw} = "}" }',
	'{ $h{qx} = "}" }',
){
	my ($e,$r) = extract_codeblock $_;
	print "Code: $_\nExtracted: $e\nRemainder: $r\n\$\@: $@\n\n";
}
##</code><code>##

Code: { $h{x}  = "}" }
Extracted: { $h{x}  = "}" }
Remainder: 

Code: { $h{s}  = "}" }
Extracted: 
Remainder: { $h{s}  = "}" }

Code: { $h{s}  = 1; print "{oops}" }
Extracted: 
Remainder: { $h{s}  = 1; print "{oops}" }

Code: { $h{m}  = "}" }
Extracted: 
Remainder: { $h{m}  = "}" }

Code: { $h{y}  = "}" }
Extracted: 
Remainder: { $h{y}  = "}" }

Code: { $h{tr} = "}" }
Extracted: 
Remainder: { $h{tr} = "}" }
##</code><code>##

#!/usr/bin/perl -w -s
use strict;
use Parse::RecDescent;
my $parser;
$parser = Parse::RecDescent->new(q({my %foo} rule:"foo"{$foo{x}="}";}));
$parser = Parse::RecDescent->new(q({my %foo} rule:"foo"{$foo{s}="}";}));
$parser = Parse::RecDescent->new(q({my %foo} rule:"foo"{$foo{y}="}";}));
$parser = Parse::RecDescent->new(q({my %foo} rule:"foo"{$foo{m}="}";}));
$parser = Parse::RecDescent->new(q({my %foo} rule:"foo"{$foo{tr}="}";}));
##</code><code>##

    Parse::RecDescent: Treating "{my %foo}" as an action
    Parse::RecDescent: Treating "rule:" as a rule declaration
    Parse::RecDescent: Treating ""foo"" as an interpolated literal terminal
    Parse::RecDescent: Treating "{$foo{x}="}";}" as an action
printing code (4142) to RD_TRACE
    Parse::RecDescent: Treating "{my %foo}" as an action
    Parse::RecDescent: Treating "rule:" as a rule declaration
    Parse::RecDescent: Treating ""foo"" as an interpolated literal terminal
printing code (3618) to RD_TRACE
    Parse::RecDescent: Treating "{my %foo}" as an action
    Parse::RecDescent: Treating "rule:" as a rule declaration
    Parse::RecDescent: Treating ""foo"" as an interpolated literal terminal
printing code (3618) to RD_TRACE
    Parse::RecDescent: Treating "{my %foo}" as an action
    Parse::RecDescent: Treating "rule:" as a rule declaration
    Parse::RecDescent: Treating ""foo"" as an interpolated literal terminal
printing code (3618) to RD_TRACE
    Parse::RecDescent: Treating "{my %foo}" as an action
    Parse::RecDescent: Treating "rule:" as a rule declaration
    Parse::RecDescent: Treating ""foo"" as an interpolated literal terminal
printing code (3618) to RD_TRACE