FM / perl5

/usr/share/perl5

Name	Size	Mode	Actions
App/	-	0755	rm
Archive/	-	0755	rm
Attribute/	-	0755	rm
autodie/	-	0755	rm
B/	-	0755	rm
Carp/	-	0755	rm
CGI/	-	0755	rm
Class/	-	0755	rm
Config/	-	0755	rm
CPAN/	-	0755	rm
CPANPLUS/	-	0755	rm
DBIx/	-	0755	rm
DBM_Filter/	-	0755	rm
Devel/	-	0755	rm
Digest/	-	0755	rm
Encode/	-	0755	rm
encoding/	-	0755	rm
Exporter/	-	0755	rm
ExtUtils/	-	0755	rm
File/	-	0755	rm
Filter/	-	0755	rm
Getopt/	-	0755	rm
HTML/	-	0755	rm
I18N/	-	0755	rm
IO/	-	0755	rm
IPC/	-	0755	rm
JSON/	-	0755	rm
Locale/	-	0755	rm
Log/	-	0755	rm
Math/	-	0755	rm
Memoize/	-	0755	rm
Module/	-	0755	rm
Net/	-	0755	rm
Object/	-	0755	rm
overload/	-	0755	rm
Package/	-	0755	rm
Params/	-	0755	rm
Parse/	-	0755	rm
PerlIO/	-	0755	rm
Pod/	-	0755	rm
pod/	-	0755	rm
Search/	-	0755	rm
TAP/	-	0755	rm
Term/	-	0755	rm
Test/	-	0755	rm
Test2/	-	0755	rm
Text/	-	0755	rm
Thread/	-	0755	rm
Tie/	-	0755	rm
Time/	-	0755	rm
Unicode/	-	0755	rm
unicore/	-	0755	rm
URI/	-	0755	rm
User/	-	0755	rm
vendor_perl/	-	0755	rm
version/	-	0755	rm
warnings/	-	0755	rm
abbrev.pl	838	0644	edit dl rm
AnyDBM_File.pm	2594	0644	edit dl rm
assert.pl	1298	0644	edit dl rm
attributes.pm	14877	0644	edit dl rm
autodie.pm	11763	0644	edit dl rm
AutoLoader.pm	14997	0644	edit dl rm
AutoSplit.pm	19637	0644	edit dl rm
autouse.pm	4238	0644	edit dl rm
base.pm	6986	0644	edit dl rm
Benchmark.pm	28530	0644	edit dl rm
bigfloat.pl	7368	0644	edit dl rm
bigint.pl	8959	0644	edit dl rm
bigint.pm	17852	0644	edit dl rm
bignum.pm	18673	0644	edit dl rm
bigrat.pl	4476	0644	edit dl rm
bigrat.pm	14442	0644	edit dl rm
blib.pm	2106	0644	edit dl rm
bytes.pm	2384	0644	edit dl rm
bytes_heavy.pl	758	0644	edit dl rm
cacheout.pl	1122	0644	edit dl rm
Carp.pm	7611	0644	edit dl rm
CGI.pm	261478	0644	edit dl rm
charnames.pm	15670	0644	edit dl rm
complete.pl	3191	0644	edit dl rm
constant.pm	12528	0644	edit dl rm
CORE.pod	1569	0644	edit dl rm
CPAN.pm	130907	0644	edit dl rm
CPANPLUS.pm	7269	0644	edit dl rm
ctime.pl	1993	0644	edit dl rm
DB.pm	19202	0644	edit dl rm
DBM_Filter.pm	14415	0644	edit dl rm
diagnostics.pm	17380	0644	edit dl rm
Digest.pm	10412	0644	edit dl rm
DirHandle.pm	1937	0644	edit dl rm
dotsh.pl	2175	0644	edit dl rm
Dumpvalue.pm	16899	0644	edit dl rm
dumpvar.pl	15275	0644	edit dl rm
English.pm	4488	0644	edit dl rm
Env.pm	5170	0644	edit dl rm
exceptions.pl	1736	0644	edit dl rm
Expect.pm	54725	0644	edit dl rm
Expect.pod	43735	0644	edit dl rm
Exporter.pm	18595	0644	edit dl rm
fastcwd.pl	1019	0644	edit dl rm
Fatal.pm	40966	0644	edit dl rm
feature.pm	5092	0644	edit dl rm
fields.pm	9507	0644	edit dl rm
FileCache.pm	5570	0644	edit dl rm
FileHandle.pm	6778	0644	edit dl rm
filetest.pm	4003	0644	edit dl rm
find.pl	1185	0644	edit dl rm
FindBin.pm	5658	0644	edit dl rm
finddepth.pl	1130	0644	edit dl rm
flush.pl	642	0644	edit dl rm
getcwd.pl	1427	0644	edit dl rm
getopt.pl	1322	0644	edit dl rm
getopts.pl	1406	0644	edit dl rm
hostname.pl	727	0644	edit dl rm
if.pm	1166	0644	edit dl rm
importenv.pl	283	0644	edit dl rm
integer.pm	3266	0644	edit dl rm
less.pm	3084	0644	edit dl rm
locale.pm	820	0644	edit dl rm
look.pl	1255	0644	edit dl rm
Memoize.pm	35295	0644	edit dl rm
newgetopt.pl	2213	0644	edit dl rm
NEXT.pm	18481	0644	edit dl rm
ok.pm	967	0444	edit dl rm
open.pm	7740	0644	edit dl rm
open2.pl	185	0644	edit dl rm
open3.pl	185	0644	edit dl rm
overload.pm	48050	0644	edit dl rm
overloading.pm	1801	0644	edit dl rm
parent.pm	2998	0644	edit dl rm
perl5db.pl	317682	0644	edit dl rm
PerlIO.pm	11122	0644	edit dl rm
pwd.pl	1478	0644	edit dl rm
Safe.pm	24326	0644	edit dl rm
SelectSaver.pm	1076	0644	edit dl rm
SelfLoader.pm	17341	0644	edit dl rm
Shell.pm	8685	0644	edit dl rm
shellwords.pl	276	0644	edit dl rm
sigtrap.pm	7611	0644	edit dl rm
sort.pm	6093	0644	edit dl rm
stat.pl	590	0644	edit dl rm
strict.pm	3716	0644	edit dl rm
subs.pm	842	0644	edit dl rm
Switch.pm	28508	0644	edit dl rm
Symbol.pm	4794	0644	edit dl rm
syslog.pl	4806	0644	edit dl rm
tainted.pl	164	0644	edit dl rm
termcap.pl	4114	0644	edit dl rm
Test.pm	28800	0644	edit dl rm
Test2.pm	6393	0444	edit dl rm
Thread.pm	8285	0644	edit dl rm
timelocal.pl	690	0644	edit dl rm
UNIVERSAL.pm	6536	0644	edit dl rm
utf8.pm	6918	0644	edit dl rm
utf8_heavy.pl	8001	0644	edit dl rm
validate.pl	3731	0644	edit dl rm
vars.pm	2358	0644	edit dl rm
version.pm	1037	0644	edit dl rm
version.pod	12315	0644	edit dl rm
vmsish.pm	4328	0644	edit dl rm
warnings.pm	16133	0644	edit dl rm

Edit: /usr/share/perl5/Switch.pm (28508B)

package Switch;

use strict;
use vars qw($VERSION);
use Carp;

$VERSION = '2.14';

# LOAD FILTERING MODULE...
use Filter::Util::Call;

sub __();

# CATCH ATTEMPTS TO CALL case OUTSIDE THE SCOPE OF ANY switch

$::_S_W_I_T_C_H = sub { croak "case/when statement not in switch/given block" };

my $offset;
my $fallthrough;
my ($Perl5, $Perl6) = (0,0);

sub import
{
	$fallthrough = grep /\bfallthrough\b/, @_;
	$offset = (caller)[2]+1;
	filter_add({}) unless @_>1 && $_[1] eq 'noimport';
	my $pkg = caller;
	no strict 'refs';
	for ( qw( on_defined on_exists ) )
	{
		*{"${pkg}::$_"} = \&$_;
	}
	*{"${pkg}::__"} = \&__ if grep /__/, @_;
	$Perl6 = 1 if grep(/Perl\s*6/i, @_);
	$Perl5 = 1 if grep(/Perl\s*5/i, @_) || !grep(/Perl\s*6/i, @_);
	1;
}

sub unimport
{	
	filter_del()
}

sub filter
{
	my($self) = @_ ;
	local $Switch::file = (caller)[1];

my $status = 1;
	$status = filter_read(1_000_000);
	return $status if $status<0;
    	$_ = filter_blocks($_,$offset);
	$_ = "# line $offset\n" . $_ if $offset; undef $offset;
	return $status;
}

use Text::Balanced ':ALL';

sub line
{
	my ($pretext,$offset) = @_;
	($pretext=~tr/\n/\n/)+($offset||0);
}

sub is_block
{
	local $SIG{__WARN__}=sub{die$@};
	local $^W=1;
	my $ishash = defined  eval 'my $hr='.$_[0];
	undef $@;
	return !$ishash;
}

my $pod_or_DATA = qr/ ^=[A-Za-z] .*? ^=cut (?![A-Za-z]) .*? $
		    | ^__(DATA|END)__\n.*
		    /smx;

my $casecounter = 1;
sub filter_blocks
{
	my ($source, $line) = @_;
	return $source unless $Perl5 && $source =~ /case|switch/
			   || $Perl6 && $source =~ /when|given|default/;
	pos $source = 0;
	my $text = "";
	component: while (pos $source < length $source)
	{
		if ($source =~ m/(\G\s*use\s+Switch\b)/gc)
		{
			$text .= q{use Switch 'noimport'};
			next component;
		}
		my @pos = Text::Balanced::_match_quotelike(\$source,qr/\s*/,1,0);
		if (defined $pos[0])
		{
			my $pre = substr($source,$pos[0],$pos[1]); # matched prefix
                        my $iEol;
                        if( substr($source,$pos[4],$pos[5]) eq '/' && # 1st delimiter
                            substr($source,$pos[2],$pos[3]) eq '' && # no op like 'm'
                            index( substr($source,$pos[16],$pos[17]), 'x' ) == -1 && # no //x
                            ($iEol = index( $source, "\n", $pos[4] )) > 0         &&
                            $iEol < $pos[8] ){ # embedded newlines
                            # If this is a pattern, it isn't compatible with Switch. Backup past 1st '/'.
                            pos( $source ) = $pos[6];
			    $text .= $pre . substr($source,$pos[2],$pos[6]-$pos[2]);
			} else {
			    $text .= $pre . substr($source,$pos[2],$pos[18]-$pos[2]);
			}
			next component;
		}
		if ($source =~ m/(\G\s*$pod_or_DATA)/gc) {
			$text .= $1;
			next component;
		}
		@pos = Text::Balanced::_match_variable(\$source,qr/\s*/);
		if (defined $pos[0])
		{
			$text .= " " if $pos[0] < $pos[2];
			$text .= substr($source,$pos[0],$pos[4]-$pos[0]);
			next component;
		}

if ($Perl5 && $source =~ m/\G(\n*)(\s*)(switch)\b(?=\s*[(])/gc
		 || $Perl6 && $source =~ m/\G(\n*)(\s*)(given)\b(?=\s*[(])/gc
		 || $Perl6 && $source =~ m/\G(\n*)(\s*)(given)\b(.*)(?=\{)/gc)
		{
			my $keyword = $3;
			my $arg = $4;
			$text .= $1.$2.'S_W_I_T_C_H: while (1) ';
			unless ($arg) {
				@pos = Text::Balanced::_match_codeblock(\$source,qr/\s*/,qr/$/,qr/$/,qr/[[{(<]/,qr/[]})>]/,undef) 
				or do {
					die "Bad $keyword statement (problem in the parentheses?) near $Switch::file line ", line(substr($source,0,pos $source),$line), "\n";
				};
				$arg = filter_blocks(substr($source,$pos[0],$pos[4]-$pos[0]),line(substr($source,0,$pos[0]),$line));
			}
			$arg =~ s {^\s*[(]\s*%}   { ( \\\%}	||
			$arg =~ s {^\s*[(]\s*m\b} { ( qr}	||
			$arg =~ s {^\s*[(]\s*/}   { ( qr/}	||
			$arg =~ s {^\s*[(]\s*qw}  { ( \\qw};
			@pos = Text::Balanced::_match_codeblock(\$source,qr/\s*/,qr/\{/,qr/\}/,qr/\{/,qr/\}/,undef)
			or do {
				die "Bad $keyword statement (problem in the code block?) near $Switch::file line ", line(substr($source,0, pos $source), $line), "\n";
			};
			my $code = filter_blocks(substr($source,$pos[0],$pos[4]-$pos[0]),line(substr($source,0,$pos[0]),$line));
			$code =~ s/{/{ local \$::_S_W_I_T_C_H; Switch::switch $arg;/;
			$text .= $code . 'continue {last}';
			next component;
		}
		elsif ($Perl5 && $source =~ m/\G(\s*)(case\b)(?!\s*=>)/gc
		    || $Perl6 && $source =~ m/\G(\s*)(when\b)(?!\s*=>)/gc
		    || $Perl6 && $source =~ m/\G(\s*)(default\b)(?=\s*\{)/gc)
		{
			my $keyword = $2;
			$text .= $1 . ($keyword eq "default"
					? "if (1)"
					: "if (Switch::case");

if ($keyword eq "default") {
				# Nothing to do
			}
			elsif (@pos = Text::Balanced::_match_codeblock(\$source,qr/\s*/,qr/\{/,qr/\}/,qr/\{/,qr/\}/,undef)) {
				my $code = substr($source,$pos[0],$pos[4]-$pos[0]);
				$text .= " " if $pos[0] < $pos[2];
				$text .= "sub " if is_block $code;
				$text .= filter_blocks($code,line(substr($source,0,$pos[0]),$line)) . ")";
			}
			elsif (@pos = Text::Balanced::_match_codeblock(\$source,qr/\s*/,qr/[[(]/,qr/[])]/,qr/[[({]/,qr/[])}]/,undef)) {
				my $code = filter_blocks(substr($source,$pos[0],$pos[4]-$pos[0]),line(substr($source,0,$pos[0]),$line));
				$code =~ s {^\s*[(]\s*%}   { ( \\\%}	||
				$code =~ s {^\s*[(]\s*m\b} { ( qr}	||
				$code =~ s {^\s*[(]\s*/}   { ( qr/}	||
				$code =~ s {^\s*[(]\s*qw}  { ( \\qw};
				$text .= " " if $pos[0] < $pos[2];
				$text .= "$code)";
			}
			elsif ($Perl6 && do{@pos = Text::Balanced::_match_variable(\$source,qr/\s*/)}) {
				my $code = filter_blocks(substr($source,$pos[0],$pos[4]-$pos[0]),line(substr($source,0,$pos[0]),$line));
				$code =~ s {^\s*%}  { \%}	||
				$code =~ s {^\s*@}  { \@};
				$text .= " " if $pos[0] < $pos[2];
				$text .= "$code)";
			}
			elsif ( @pos = Text::Balanced::_match_quotelike(\$source,qr/\s*/,1,0)) {
				my $code = substr($source,$pos[2],$pos[18]-$pos[2]);
				$code = filter_blocks($code,line(substr($source,0,$pos[2]),$line));
				$code =~ s {^\s*m}  { qr}	||
				$code =~ s {^\s*/}  { qr/}	||
				$code =~ s {^\s*qw} { \\qw};
				$text .= " " if $pos[0] < $pos[2];
				$text .= "$code)";
			}
			elsif ($Perl5 && $source =~ m/\G\s*(([^\$\@{])[^\$\@{]*)(?=\s*{)/gc
			   ||  $Perl6 && $source =~ m/\G\s*([^;{]*)()/gc) {
				my $code = filter_blocks($1,line(substr($source,0,pos $source),$line));
				$text .= ' \\' if $2 eq '%';
				$text .= " $code)";
			}
			else {
				die "Bad $keyword statement (invalid $keyword value?) near $Switch::file line ", line(substr($source,0,pos $source), $line), "\n";
			}

die "Missing opening brace or semi-colon after 'when' value near $Switch::file line ", line(substr($source,0,pos $source), $line), "\n"
				unless !$Perl6 || $source =~ m/\G(\s*)(?=;|\{)/gc;

do{@pos = Text::Balanced::_match_codeblock(\$source,qr/\s*/,qr/\{/,qr/\}/,qr/\{/,qr/\}/,undef)}
			or do {
				if ($source =~ m/\G\s*(?=([};]|\Z))/gc) {
					$casecounter++;
					next component;
				}
				die "Bad $keyword statement (problem in the code block?) near $Switch::file line ", line(substr($source,0,pos $source),$line), "\n";
			};
			my $code = filter_blocks(substr($source,$pos[0],$pos[4]-$pos[0]),line(substr($source,0,$pos[0]),$line));
			$code =~ s/}(?=\s*\Z)/;last S_W_I_T_C_H }/
				unless $fallthrough;
			$text .= "{ while (1) $code continue { goto C_A_S_E_$casecounter } last S_W_I_T_C_H; C_A_S_E_$casecounter: }";
			$casecounter++;
			next component;
		}

$source =~ m/\G(\s*(-[sm]\s+|\w+|#.*\n|\W))/gc;
		$text .= $1;
	}
	$text;
}

sub in
{
	my ($x,$y) = @_;
	my @numy;
	for my $nextx ( @$x )
	{
		my $numx = ref($nextx) || defined $nextx && (~$nextx&$nextx) eq 0;
		for my $j ( 0..$#$y )
		{
			my $nexty = $y->[$j];
			push @numy, ref($nexty) || defined $nexty && (~$nexty&$nexty) eq 0
				if @numy <= $j;
			return 1 if $numx && $numy[$j] && $nextx==$nexty
			         || $nextx eq $nexty;
			
		}
	}
	return "";
}

sub on_exists
{
	my $ref = @_==1 && ref($_[0]) eq 'HASH' ? $_[0] : { @_ };
	[ keys %$ref ]
}

sub on_defined
{
	my $ref = @_==1 && ref($_[0]) eq 'HASH' ? $_[0] : { @_ };
	[ grep { defined $ref->{$_} } keys %$ref ]
}

sub switch(;$)
{
	my ($s_val) = @_ ? $_[0] : $_;
	my $s_ref = ref $s_val;
	
	if ($s_ref eq 'CODE')
	{
		$::_S_W_I_T_C_H =
		      sub { my $c_val = $_[0];
			    return $s_val == $c_val  if ref $c_val eq 'CODE';
			    return $s_val->(@$c_val) if ref $c_val eq 'ARRAY';
			    return $s_val->($c_val);
			  };
	}
	elsif ($s_ref eq "" && defined $s_val && (~$s_val&$s_val) eq 0)	# NUMERIC SCALAR
	{
		$::_S_W_I_T_C_H =
		      sub { my $c_val = $_[0];
			    my $c_ref = ref $c_val;
			    return $s_val == $c_val 	if $c_ref eq ""
							&& defined $c_val
							&& (~$c_val&$c_val) eq 0;
			    return $s_val eq $c_val 	if $c_ref eq "";
			    return in([$s_val],$c_val)	if $c_ref eq 'ARRAY';
			    return $c_val->($s_val)	if $c_ref eq 'CODE';
			    return $c_val->call($s_val)	if $c_ref eq 'Switch';
			    return scalar $s_val=~/$c_val/
							if $c_ref eq 'Regexp';
			    return scalar $c_val->{$s_val}
							if $c_ref eq 'HASH';
		            return;	
			  };
	}
	elsif ($s_ref eq "")				# STRING SCALAR
	{
		$::_S_W_I_T_C_H =
		      sub { my $c_val = $_[0];
			    my $c_ref = ref $c_val;
			    return $s_val eq $c_val 	if $c_ref eq "";
			    return in([$s_val],$c_val)	if $c_ref eq 'ARRAY';
			    return $c_val->($s_val)	if $c_ref eq 'CODE';
			    return $c_val->call($s_val)	if $c_ref eq 'Switch';
			    return scalar $s_val=~/$c_val/
							if $c_ref eq 'Regexp';
			    return scalar $c_val->{$s_val}
							if $c_ref eq 'HASH';
		            return;	
			  };
	}
	elsif ($s_ref eq 'ARRAY')
	{
		$::_S_W_I_T_C_H =
		      sub { my $c_val = $_[0];
			    my $c_ref = ref $c_val;
			    return in($s_val,[$c_val]) 	if $c_ref eq "";
			    return in($s_val,$c_val)	if $c_ref eq 'ARRAY';
			    return $c_val->(@$s_val)	if $c_ref eq 'CODE';
			    return $c_val->call(@$s_val)
							if $c_ref eq 'Switch';
			    return scalar grep {$_=~/$c_val/} @$s_val
							if $c_ref eq 'Regexp';
			    return scalar grep {$c_val->{$_}} @$s_val
							if $c_ref eq 'HASH';
		            return;	
			  };
	}
	elsif ($s_ref eq 'Regexp')
	{
		$::_S_W_I_T_C_H =
		      sub { my $c_val = $_[0];
			    my $c_ref = ref $c_val;
			    return $c_val=~/s_val/ 	if $c_ref eq "";
			    return scalar grep {$_=~/s_val/} @$c_val
							if $c_ref eq 'ARRAY';
			    return $c_val->($s_val)	if $c_ref eq 'CODE';
			    return $c_val->call($s_val)	if $c_ref eq 'Switch';
			    return $s_val eq $c_val	if $c_ref eq 'Regexp';
			    return grep {$_=~/$s_val/ && $c_val->{$_}} keys %$c_val
							if $c_ref eq 'HASH';
		            return;	
			  };
	}
	elsif ($s_ref eq 'HASH')
	{
		$::_S_W_I_T_C_H =
		      sub { my $c_val = $_[0];
			    my $c_ref = ref $c_val;
			    return $s_val->{$c_val} 	if $c_ref eq "";
			    return scalar grep {$s_val->{$_}} @$c_val
							if $c_ref eq 'ARRAY';
			    return $c_val->($s_val)	if $c_ref eq 'CODE';
			    return $c_val->call($s_val)	if $c_ref eq 'Switch';
			    return grep {$_=~/$c_val/ && $s_val->{"$_"}} keys %$s_val
							if $c_ref eq 'Regexp';
			    return $s_val==$c_val	if $c_ref eq 'HASH';
		            return;	
			  };
	}
	elsif ($s_ref eq 'Switch')
	{
		$::_S_W_I_T_C_H =
		      sub { my $c_val = $_[0];
			    return $s_val == $c_val  if ref $c_val eq 'Switch';
			    return $s_val->call(@$c_val)
						     if ref $c_val eq 'ARRAY';
			    return $s_val->call($c_val);
			  };
	}
	else
	{
		croak "Cannot switch on $s_ref";
	}
	return 1;
}

sub case($) { local $SIG{__WARN__} = \&carp;
	      $::_S_W_I_T_C_H->(@_); }

# IMPLEMENT __

my $placeholder = bless { arity=>1, impl=>sub{$_[1+$_[0]]} };

sub __() { $placeholder }

sub __arg($)
{
	my $index = $_[0]+1;
	bless { arity=>0, impl=>sub{$_[$index]} };
}

sub hosub(&@)
{
	# WRITE THIS
}

sub call
{
	my ($self,@args) = @_;
	return $self->{impl}->(0,@args);
}

sub meta_bop(&)
{
	my ($op) = @_;
	sub
	{
		my ($left, $right, $reversed) = @_;
		($right,$left) = @_ if $reversed;

my $rop = ref $right eq 'Switch'
			? $right
			: bless { arity=>0, impl=>sub{$right} };

my $lop = ref $left eq 'Switch'
			? $left
			: bless { arity=>0, impl=>sub{$left} };

my $arity = $lop->{arity} + $rop->{arity};

return bless {
				arity => $arity,
				impl  => sub { my $start = shift;
					       return $op->($lop->{impl}->($start,@_),
						            $rop->{impl}->($start+$lop->{arity},@_));
					     }
			     };
	};
}

sub meta_uop(&)
{
	my ($op) = @_;
	sub
	{
		my ($left) = @_;

my $lop = ref $left eq 'Switch'
			? $left
			: bless { arity=>0, impl=>sub{$left} };

my $arity = $lop->{arity};

return bless {
				arity => $arity,
				impl  => sub { $op->($lop->{impl}->(@_)) }
			     };
	};
}

use overload
	"+"	=> 	meta_bop {$_[0] + $_[1]},
	"-"	=> 	meta_bop {$_[0] - $_[1]},  
	"*"	=>  	meta_bop {$_[0] * $_[1]},
	"/"	=>  	meta_bop {$_[0] / $_[1]},
	"%"	=>  	meta_bop {$_[0] % $_[1]},
	"**"	=>  	meta_bop {$_[0] ** $_[1]},
	"<<"	=>  	meta_bop {$_[0] << $_[1]},
	">>"	=>  	meta_bop {$_[0] >> $_[1]},
	"x"	=>  	meta_bop {$_[0] x $_[1]},
	"."	=>  	meta_bop {$_[0] . $_[1]},
	"<"	=>  	meta_bop {$_[0] < $_[1]},
	"<="	=>  	meta_bop {$_[0] <= $_[1]},
	">"	=>  	meta_bop {$_[0] > $_[1]},
	">="	=>  	meta_bop {$_[0] >= $_[1]},
	"=="	=>  	meta_bop {$_[0] == $_[1]},
	"!="	=>  	meta_bop {$_[0] != $_[1]},
	"<=>"	=>  	meta_bop {$_[0] <=> $_[1]},
	"lt"	=>  	meta_bop {$_[0] lt $_[1]},
	"le"	=> 	meta_bop {$_[0] le $_[1]},
	"gt"	=> 	meta_bop {$_[0] gt $_[1]},
	"ge"	=> 	meta_bop {$_[0] ge $_[1]},
	"eq"	=> 	meta_bop {$_[0] eq $_[1]},
	"ne"	=> 	meta_bop {$_[0] ne $_[1]},
	"cmp"	=> 	meta_bop {$_[0] cmp $_[1]},
	"\&"	=> 	meta_bop {$_[0] & $_[1]},
	"^"	=> 	meta_bop {$_[0] ^ $_[1]},
	"|"	=>	meta_bop {$_[0] | $_[1]},
	"atan2"	=>	meta_bop {atan2 $_[0], $_[1]},

"neg"	=>	meta_uop {-$_[0]},
	"!"	=>	meta_uop {!$_[0]},
	"~"	=>	meta_uop {~$_[0]},
	"cos"	=>	meta_uop {cos $_[0]},
	"sin"	=>	meta_uop {sin $_[0]},
	"exp"	=>	meta_uop {exp $_[0]},
	"abs"	=>	meta_uop {abs $_[0]},
	"log"	=>	meta_uop {log $_[0]},
	"sqrt"  =>	meta_uop {sqrt $_[0]},
	"bool"  =>	sub { croak "Can't use && or || in expression containing __" },

#	"&()"	=>	sub { $_[0]->{impl} },

#	"||"	=>	meta_bop {$_[0] || $_[1]},
	#	"&&"	=>	meta_bop {$_[0] && $_[1]},
	# fallback => 1,
	;
1;

__END__

=head1 NAME

Switch - A switch statement for Perl

=head1 VERSION

This document describes version 2.14 of Switch,
released Dec 29, 2008.

=head1 SYNOPSIS

use Switch;

switch ($val) {
	case 1		{ print "number 1" }
	case "a"	{ print "string a" }
	case [1..10,42]	{ print "number in list" }
	case (\@array)	{ print "number in list" }
	case /\w+/	{ print "pattern" }
	case qr/\w+/	{ print "pattern" }
	case (\%hash)	{ print "entry in hash" }
	case (\&sub)	{ print "arg to subroutine" }
	else		{ print "previous case not true" }
    }

=head1 BACKGROUND

[Skip ahead to L<"DESCRIPTION"> if you don't care about the whys
and wherefores of this control structure]

In seeking to devise a "Swiss Army" case mechanism suitable for Perl,
it is useful to generalize this notion of distributed conditional
testing as far as possible. Specifically, the concept of "matching"
between the switch value and the various case values need not be
restricted to numeric (or string or referential) equality, as it is in other 
languages. Indeed, as Table 1 illustrates, Perl
offers at least eighteen different ways in which two values could
generate a match.

Table 1: Matching a switch value ($s) with a case value ($c)

Switch  Case    Type of Match Implied   Matching Code
        Value   Value   
        ======  =====   =====================   =============

number  same    numeric or referential  match if $s == $c;
        or ref          equality

object  method	result of method call   match if $s->$c();
	ref     name 				match if defined $s->$c();
		or ref

other   other   string equality         match if $s eq $c;
        non-ref non-ref
        scalar  scalar

string  regexp  pattern match           match if $s =~ /$c/;

array   scalar  array entry existence   match if 0<=$c && $c<@$s;
        ref             array entry definition  match if defined $s->[$c];
                        array entry truth       match if $s->[$c];

array   array   array intersection      match if intersects(@$s, @$c);
        ref     ref     (apply this table to
                         all pairs of elements
                         $s->[$i] and
                         $c->[$j])

array   regexp  array grep              match if grep /$c/, @$s;
        ref

hash    scalar  hash entry existence    match if exists $s->{$c};
        ref             hash entry definition   match if defined $s->{$c};
                        hash entry truth        match if $s->{$c};

hash    regexp  hash grep               match if grep /$c/, keys %$s;
        ref

sub     scalar  return value defn       match if defined $s->($c);
        ref             return value truth      match if $s->($c);

sub     array   return value defn       match if defined $s->(@$c);
        ref     ref     return value truth      match if $s->(@$c);

In reality, Table 1 covers 31 alternatives, because only the equality and
intersection tests are commutative; in all other cases, the roles of
the C<$s> and C<$c> variables could be reversed to produce a
different test. For example, instead of testing a single hash for
the existence of a series of keys (C<match if exists $s-E<gt>{$c}>),
one could test for the existence of a single key in a series of hashes
(C<match if exists $c-E<gt>{$s}>).

=head1 DESCRIPTION

The Switch.pm module implements a generalized case mechanism that covers
most (but not all) of the numerous possible combinations of switch and case
values described above.

The module augments the standard Perl syntax with two new control
statements: C<switch> and C<case>. The C<switch> statement takes a
single scalar argument of any type, specified in parentheses.
C<switch> stores this value as the
current switch value in a (localized) control variable.
The value is followed by a block which may contain one or more
Perl statements (including the C<case> statement described below).
The block is unconditionally executed once the switch value has
been cached.

A C<case> statement takes a single scalar argument (in mandatory
parentheses if it's a variable; otherwise the parens are optional) and
selects the appropriate type of matching between that argument and the
current switch value. The type of matching used is determined by the
respective types of the switch value and the C<case> argument, as
specified in Table 1. If the match is successful, the mandatory
block associated with the C<case> statement is executed.

In most other respects, the C<case> statement is semantically identical
to an C<if> statement. For example, it can be followed by an C<else>
clause, and can be used as a postfix statement qualifier.

However, when a C<case> block has been executed control is automatically
transferred to the statement after the immediately enclosing C<switch>
block, rather than to the next statement within the block. In other
words, the success of any C<case> statement prevents other cases in the
same scope from executing. But see L<"Allowing fall-through"> below.

Together these two new statements provide a fully generalized case
mechanism:

use Switch;

# AND LATER...

%special = ( woohoo => 1,  d'oh => 1 );

while (<>) {
	    chomp;
            switch ($_) {
                case (%special) { print "homer\n"; }      # if $special{$_}
                case /[a-z]/i   { print "alpha\n"; }      # if $_ =~ /a-z/i
                case [1..9]     { print "small num\n"; }  # if $_ in [1..9]
                case { $_[0] >= 10 } { print "big num\n"; } # if $_ >= 10
                print "must be punctuation\n" case /\W/;  # if $_ ~= /\W/
	    }
        }

Note that C<switch>es can be nested within C<case> (or any other) blocks,
and a series of C<case> statements can try different types of matches
-- hash membership, pattern match, array intersection, simple equality,
etc. -- against the same switch value.

The use of intersection tests against an array reference is particularly
useful for aggregating integral cases:

sub classify_digit
        {
                switch ($_[0]) { case 0            { return 'zero' }
                                 case [2,4,6,8]    { return 'even' }
                                 case [1,3,5,7,9]  { return 'odd' }
                                 case /[A-F]/i     { return 'hex' }
                               }
        }

=head2 Allowing fall-through

Fall-though (trying another case after one has already succeeded)
is usually a Bad Idea in a switch statement. However, this
is Perl, not a police state, so there I<is> a way to do it, if you must.

If a C<case> block executes an untargeted C<next>, control is
immediately transferred to the statement I<after> the C<case> statement
(i.e. usually another case), rather than out of the surrounding
C<switch> block.

For example:

switch ($val) {
                case 1      { handle_num_1(); next }    # and try next case...
                case "1"    { handle_str_1(); next }    # and try next case...
                case [0..9] { handle_num_any(); }       # and we're done
                case /\d/   { handle_dig_any(); next }  # and try next case...
                case /.*/   { handle_str_any(); next }  # and try next case...
        }

If $val held the number C<1>, the above C<switch> block would call the
first three C<handle_...> subroutines, jumping to the next case test
each time it encountered a C<next>. After the third C<case> block
was executed, control would jump to the end of the enclosing
C<switch> block.

On the other hand, if $val held C<10>, then only the last two C<handle_...>
subroutines would be called.

Note that this mechanism allows the notion of I<conditional fall-through>.
For example:

switch ($val) {
                case [0..9] { handle_num_any(); next if $val < 7; }
                case /\d/   { handle_dig_any(); }
        }

If an untargeted C<last> statement is executed in a case block, this
immediately transfers control out of the enclosing C<switch> block
(in other words, there is an implicit C<last> at the end of each
normal C<case> block). Thus the previous example could also have been
written:

switch ($val) {
                case [0..9] { handle_num_any(); last if $val >= 7; next; }
                case /\d/   { handle_dig_any(); }
        }

=head2 Automating fall-through

In situations where case fall-through should be the norm, rather than an
exception, an endless succession of terminal C<next>s is tedious and ugly.
Hence, it is possible to reverse the default behaviour by specifying
the string "fallthrough" when importing the module. For example, the 
following code is equivalent to the first example in L<"Allowing fall-through">:

use Switch 'fallthrough';

switch ($val) {
                case 1      { handle_num_1(); }
                case "1"    { handle_str_1(); }
                case [0..9] { handle_num_any(); last }
                case /\d/   { handle_dig_any(); }
                case /.*/   { handle_str_any(); }
        }

Note the explicit use of a C<last> to preserve the non-fall-through
behaviour of the third case.

=head2 Alternative syntax

Perl 6 will provide a built-in switch statement with essentially the
same semantics as those offered by Switch.pm, but with a different
pair of keywords. In Perl 6 C<switch> will be spelled C<given>, and
C<case> will be pronounced C<when>. In addition, the C<when> statement
will not require switch or case values to be parenthesized.

This future syntax is also (largely) available via the Switch.pm module, by
importing it with the argument C<"Perl6">.  For example:

use Switch 'Perl6';

given ($val) {
                when 1       { handle_num_1(); }
                when ($str1) { handle_str_1(); }
                when [0..9]  { handle_num_any(); last }
                when /\d/    { handle_dig_any(); }
                when /.*/    { handle_str_any(); }
                default      { handle anything else; }
        }

Note that scalars still need to be parenthesized, since they would be
ambiguous in Perl 5.

Note too that you can mix and match both syntaxes by importing the module
with:

use Switch 'Perl5', 'Perl6';

=head2 Higher-order Operations

One situation in which C<switch> and C<case> do not provide a good
substitute for a cascaded C<if>, is where a switch value needs to
be tested against a series of conditions. For example:

sub beverage {
            switch (shift) {
                case { $_[0] < 10 } { return 'milk' }
                case { $_[0] < 20 } { return 'coke' }
                case { $_[0] < 30 } { return 'beer' }
                case { $_[0] < 40 } { return 'wine' }
                case { $_[0] < 50 } { return 'malt' }
                case { $_[0] < 60 } { return 'Moet' }
                else                { return 'milk' }
            }
        }

(This is equivalent to writing C<case (sub { $_[0] < 10 })>, etc.; C<$_[0]>
is the argument to the anonymous subroutine.)

The need to specify each condition as a subroutine block is tiresome. To
overcome this, when importing Switch.pm, a special "placeholder"
subroutine named C<__> [sic] may also be imported. This subroutine
converts (almost) any expression in which it appears to a reference to a
higher-order function. That is, the expression:

use Switch '__';

__ < 2

is equivalent to:

sub { $_[0] < 2 }

With C<__>, the previous ugly case statements can be rewritten:

case  __ < 10  { return 'milk' }
        case  __ < 20  { return 'coke' }
        case  __ < 30  { return 'beer' }
        case  __ < 40  { return 'wine' }
        case  __ < 50  { return 'malt' }
        case  __ < 60  { return 'Moet' }
        else           { return 'milk' }

The C<__> subroutine makes extensive use of operator overloading to
perform its magic. All operations involving __ are overloaded to
produce an anonymous subroutine that implements a lazy version
of the original operation.

The only problem is that operator overloading does not allow the
boolean operators C<&&> and C<||> to be overloaded. So a case statement
like this:

case  0 <= __ && __ < 10  { return 'digit' }

doesn't act as expected, because when it is
executed, it constructs two higher order subroutines
and then treats the two resulting references as arguments to C<&&>:

sub { 0 <= $_[0] } && sub { $_[0] < 10 }

This boolean expression is inevitably true, since both references are
non-false. Fortunately, the overloaded C<'bool'> operator catches this
situation and flags it as an error.

=head1 DEPENDENCIES

The module is implemented using Filter::Util::Call and Text::Balanced
and requires both these modules to be installed.

=head1 AUTHOR

Damian Conway (damian@conway.org). This module is now maintained by Rafael
Garcia-Suarez (rgarciasuarez@gmail.com) and more generally by the Perl 5
Porters (perl5-porters@perl.org), as part of the Perl core.

=head1 BUGS

There are undoubtedly serious bugs lurking somewhere in code this funky :-)
Bug reports and other feedback are most welcome.

=head1 LIMITATIONS

Due to the heuristic nature of Switch.pm's source parsing, the presence of
regexes with embedded newlines that are specified with raw C</.../>
delimiters and don't have a modifier C<//x> are indistinguishable from
code chunks beginning with the division operator C</>. As a workaround
you must use C<m/.../> or C<m?...?> for such patterns. Also, the presence
of regexes specified with raw C<?...?> delimiters may cause mysterious
errors. The workaround is to use C<m?...?> instead.

Due to the way source filters work in Perl, you can't use Switch inside
an string C<eval>.

If your source file is longer then 1 million characters and you have a
switch statement that crosses the 1 million (or 2 million, etc.)
character boundary you will get mysterious errors. The workaround is to
use smaller source files.

=head1 COPYRIGHT

cmd: