[perl5.git] / lib / if.pm

package if;

our $VERSION = '0.01';

sub work {
  my $method = shift() ? 'import' : 'unimport';
  return unless shift;		# CONDITION
  my $p = shift;		# PACKAGE
  eval "require $p" or die;	# Adds .pm etc if needed
  $p->$method(@_) if $p->can($method);
}

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;

=head1 DESCRIPTION

The construct

  use if CONDITION, MODULE => ARGUMENTS;

has no effect unless C<CONDITION> is true.  In this case the effect is
the same as of

  use MODULE ARGUMENTS;

=head1 BUGS

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

=head1 AUTHOR

Ilya Zakharevich L<mailto:perl-module-if@ilyaz.org>.

=cut
Commit	Line	Data
cd16c24c IZ	1	package if;
	2
	3	our $VERSION = '0.01';
	4
	5	sub work {
	6	my $method = shift() ? 'import' : 'unimport';
	7	return unless shift; # CONDITION
	8	my $p = shift; # PACKAGE
	9	eval "require $p" or die; # Adds .pm etc if needed
	10	$p->$method(@_) if $p->can($method);
	11	}
	12
	13	sub import { shift; unshift @_, 1; goto &work }
	14	sub unimport { shift; unshift @_, 0; goto &work }
	15
	16	1;
	17	__END__
	18
	19	=head1 NAME
	20
	21	if - C<use> a Perl module if a condition holds
	22
	23	=head1 SYNOPSIS
	24
	25	use if CONDITION, MODULE => ARGUMENTS;
	26
	27	=head1 DESCRIPTION
	28
	29	The construct
	30
	31	use if CONDITION, MODULE => ARGUMENTS;
	32
	33	has no effect unless C<CONDITION> is true. In this case the effect is
	34	the same as of
	35
	36	use MODULE ARGUMENTS;
	37
	38	=head1 BUGS
	39
	40	The current implementation does not allow specification of the
	41	required version of the module.
	42
	43	=head1 AUTHOR
	44
	45	Ilya Zakharevich L<mailto:perl-module-if@ilyaz.org>.
	46
	47	=cut
	48