FM / perl5

/usr/share/perl5

Name	Size	Mode	Actions
Attribute/	-	0755	rm
B/	-	0755	rm
Class/	-	0755	rm
Compress/	-	0755	rm
Config/	-	0755	rm
CPAN/	-	0755	rm
DBM_Filter/	-	0755	rm
Devel/	-	0755	rm
encoding/	-	0755	rm
ExtUtils/	-	0755	rm
File/	-	0755	rm
Getopt/	-	0755	rm
I18N/	-	0755	rm
IO/	-	0755	rm
IPC/	-	0755	rm
Locale/	-	0755	rm
Math/	-	0755	rm
Memoize/	-	0755	rm
Module/	-	0755	rm
Net/	-	0755	rm
overload/	-	0755	rm
Pod/	-	0755	rm
pod/	-	0755	rm
Search/	-	0755	rm
Term/	-	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
warnings/	-	0755	rm
AnyDBM_File.pm	2618	0644	edit dl rm
AutoLoader.pm	15797	0644	edit dl rm
AutoSplit.pm	19637	0644	edit dl rm
autouse.pm	4238	0644	edit dl rm
base.pm	10961	0644	edit dl rm
Benchmark.pm	31026	0644	edit dl rm
blib.pm	2062	0644	edit dl rm
bytes.pm	3740	0644	edit dl rm
bytes_heavy.pl	758	0644	edit dl rm
charnames.pm	20931	0644	edit dl rm
CORE.pod	3188	0644	edit dl rm
DB.pm	18922	0644	edit dl rm
DBM_Filter.pm	14385	0644	edit dl rm
deprecate.pm	4603	0644	edit dl rm
diagnostics.pm	19299	0644	edit dl rm
DirHandle.pm	2085	0644	edit dl rm
Dumpvalue.pm	17668	0644	edit dl rm
dumpvar.pl	15555	0644	edit dl rm
English.pm	4761	0644	edit dl rm
feature.pm	19003	0644	edit dl rm
fields.pm	9475	0644	edit dl rm
FileCache.pm	5549	0644	edit dl rm
FileHandle.pm	6784	0644	edit dl rm
filetest.pm	4003	0644	edit dl rm
FindBin.pm	4561	0644	edit dl rm
if.pm	3611	0644	edit dl rm
integer.pm	3254	0644	edit dl rm
Internals.pod	2575	0644	edit dl rm
less.pm	3204	0644	edit dl rm
locale.pm	4855	0644	edit dl rm
Memoize.pm	36192	0644	edit dl rm
meta_notation.pm	2117	0644	edit dl rm
NEXT.pm	18985	0644	edit dl rm
open.pm	8512	0644	edit dl rm
overload.pm	53302	0644	edit dl rm
overloading.pm	1808	0644	edit dl rm
perl5db.pl	317094	0644	edit dl rm
PerlIO.pm	14441	0644	edit dl rm
Safe.pm	25364	0644	edit dl rm
SelectSaver.pm	1076	0644	edit dl rm
SelfLoader.pm	17686	0644	edit dl rm
sigtrap.pm	8736	0644	edit dl rm
sort.pm	3911	0644	edit dl rm
strict.pm	4738	0644	edit dl rm
subs.pm	901	0644	edit dl rm
Symbol.pm	4799	0644	edit dl rm
Test.pm	30042	0644	edit dl rm
Thread.pm	8289	0644	edit dl rm
UNIVERSAL.pm	6594	0644	edit dl rm
URI.pm	34954	0644	edit dl rm
utf8.pm	10423	0644	edit dl rm
vars.pm	2458	0644	edit dl rm
vmsish.pm	4313	0644	edit dl rm
warnings.pm	50537	0644	edit dl rm
XSLoader.pm	11252	0644	edit dl rm
_charnames.pm	34151	0644	edit dl rm

Edit: /usr/share/perl5/if.pm (3611B)

package if;

$VERSION = '0.0608';

sub work {
  my $method = shift() ? 'import' : 'unimport';
  unless (@_ >= 2) {
    my $type = ($method eq 'import') ? 'use' : 'no';
    die "Too few arguments to '$type if' (some code returning an empty list in list context?)"
  }
  return unless shift;		# CONDITION

my $p = $_[0];		# PACKAGE
  (my $file = "$p.pm") =~ s!::!/!g;
  require $file;		# Works even if $_[0] is a keyword (like open)
  my $m = $p->can($method);
  goto &$m if $m;
}

sub import   { shift; unshift @_, 1; goto &work }
sub unimport { shift; unshift @_, 0; goto &work }

1;
__END__

=head1 NAME

if - C<use> a Perl module if a condition holds

=head1 SYNOPSIS

use if CONDITION, "MODULE", ARGUMENTS;
    no  if CONDITION, "MODULE", ARGUMENTS;

=head1 DESCRIPTION

=head2 C<use if>

The C<if> module is used to conditionally load another module.  The construct:

use if CONDITION, "MODULE", ARGUMENTS;

... will load C<MODULE> only if C<CONDITION> evaluates to true; it has no
effect if C<CONDITION> evaluates to false.  (The module name, assuming it
contains at least one C<::>, must be quoted when C<'use strict "subs";'> is in
effect.)  If the CONDITION does evaluate to true, then the above line has the
same effect as:

use MODULE ARGUMENTS;

For example, the F<Unicode::UCD> module's F<charinfo> function will use two functions from F<Unicode::Normalize> only if a certain condition is met:

use if defined &DynaLoader::boot_DynaLoader,
        "Unicode::Normalize" => qw(getCombinClass NFD);

Suppose you wanted C<ARGUMENTS> to be an empty list, I<i.e.>, to have the
effect of:

use MODULE ();

You can't do this with the C<if> pragma; however, you can achieve
exactly this effect, at compile time, with:

BEGIN { require MODULE if CONDITION }

=head2 C<no if>

The C<no if> construct is mainly used to deactivate categories of warnings
when those categories would produce superfluous output under specified
versions of F<perl>.

For example, the C<redundant> category of warnings was introduced in
Perl-5.22.  This warning flags certain instances of superfluous arguments to
C<printf> and C<sprintf>.  But if your code was running warnings-free on
earlier versions of F<perl> and you don't care about C<redundant> warnings in
more recent versions, you can call:

use warnings;
    no if $] >= 5.022, q|warnings|, qw(redundant);

my $test    = { fmt  => "%s", args => [ qw( x y ) ] };
    my $result  = sprintf $test->{fmt}, @{$test->{args}};

The C<no if> construct assumes that a module or pragma has correctly
implemented an C<unimport()> method -- but most modules and pragmata have not.
That explains why the C<no if> construct is of limited applicability.

=head1 BUGS

The current implementation does not allow specification of the required
version of the module.

=head1 SEE ALSO

L<Module::Requires> can be used to conditionally load one or modules,
with constraints based on the version of the module.
Unlike C<if> though, L<Module::Requires> is not a core module.

L<Module::Load::Conditional> provides a number of functions you can use to
query what modules are available, and then load one or more of them at runtime.

The L<provide> module from CPAN can be used to select one of several possible
modules to load based on the version of Perl that is running.

=head1 AUTHOR

Ilya Zakharevich L<mailto:ilyaz@cpan.org>.

=head1 COPYRIGHT AND LICENCE

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=cut

package if; $VERSION = '0.0608'; sub work { my $method = shift() ? 'import' : 'unimport'; unless (@_ >= 2) { my $type = ($method eq 'import') ? 'use' : 'no'; die "Too few arguments to '$type if' (some code returning an empty list in list context?)" } return unless shift; # CONDITION my $p = $_[0]; # PACKAGE (my $file = "$p.pm") =~ s!::!/!g; require $file; # Works even if $_[0] is a keyword (like open) my $m = $p->can($method); goto &$m if $m; } sub import { shift; unshift @_, 1; goto &work } sub unimport { shift; unshift @_, 0; goto &work } 1; __END__ =head1 NAME if - C a Perl module if a condition holds =head1 SYNOPSIS use if CONDITION, "MODULE", ARGUMENTS; no if CONDITION, "MODULE", ARGUMENTS; =head1 DESCRIPTION =head2 C The C module is used to conditionally load another module. The construct: use if CONDITION, "MODULE", ARGUMENTS; ... will load C only if C evaluates to true; it has no effect if C evaluates to false. (The module name, assuming it contains at least one C<::>, must be quoted when C<'use strict "subs";'> is in effect.) If the CONDITION does evaluate to true, then the above line has the same effect as: use MODULE ARGUMENTS; For example, the F module's F function will use two functions from F only if a certain condition is met: use if defined &DynaLoader::boot_DynaLoader, "Unicode::Normalize" => qw(getCombinClass NFD); Suppose you wanted C to be an empty list, I, to have the effect of: use MODULE (); You can't do this with the C pragma; however, you can achieve exactly this effect, at compile time, with: BEGIN { require MODULE if CONDITION } =head2 C The C construct is mainly used to deactivate categories of warnings when those categories would produce superfluous output under specified versions of F. For example, the C category of warnings was introduced in Perl-5.22. This warning flags certain instances of superfluous arguments to C and C. But if your code was running warnings-free on earlier versions of F and you don't care about C warnings in more recent versions, you can call: use warnings; no if $] >= 5.022, q|warnings|, qw(redundant); my $test = { fmt => "%s", args => [ qw( x y ) ] }; my $result = sprintf $test->{fmt}, @{$test->{args}}; The C construct assumes that a module or pragma has correctly implemented an C method -- but most modules and pragmata have not. That explains why the C construct is of limited applicability. =head1 BUGS The current implementation does not allow specification of the required version of the module. =head1 SEE ALSO L can be used to conditionally load one or modules, with constraints based on the version of the module. Unlike C though, L is not a core module. L provides a number of functions you can use to query what modules are available, and then load one or more of them at runtime. The L module from CPAN can be used to select one of several possible modules to load based on the version of Perl that is running. =head1 AUTHOR Ilya Zakharevich L. =head1 COPYRIGHT AND LICENCE This software is copyright (c) 2002 by Ilya Zakharevich. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. =cut