1# Copyright (c) 2014 Paul Evans <leonerd@leonerd.org.uk>. All rights reserved. 2# This program is free software; you can redistribute it and/or 3# modify it under the same terms as Perl itself. 4 5package Sub::Util; 6 7use strict; 8use warnings; 9 10require Exporter; 11 12our @ISA = qw( Exporter ); 13our @EXPORT_OK = qw( 14 prototype set_prototype 15 subname set_subname 16); 17 18our $VERSION = "1.50"; 19$VERSION = eval $VERSION; 20 21require List::Util; # as it has the XS 22List::Util->VERSION( $VERSION ); # Ensure we got the right XS version (RT#100863) 23 24=head1 NAME 25 26Sub::Util - A selection of utility subroutines for subs and CODE references 27 28=head1 SYNOPSIS 29 30 use Sub::Util qw( prototype set_prototype subname set_subname ); 31 32=head1 DESCRIPTION 33 34C<Sub::Util> contains a selection of utility subroutines that are useful for 35operating on subs and CODE references. 36 37The rationale for inclusion in this module is that the function performs some 38work for which an XS implementation is essential because it cannot be 39implemented in Pure Perl, and which is sufficiently-widely used across CPAN 40that its popularity warrants inclusion in a core module, which this is. 41 42=cut 43 44=head1 FUNCTIONS 45 46=cut 47 48=head2 prototype 49 50 my $proto = prototype( $code ) 51 52I<Since version 1.40.> 53 54Returns the prototype of the given C<$code> reference, if it has one, as a 55string. This is the same as the C<CORE::prototype> operator; it is included 56here simply for symmetry and completeness with the other functions. 57 58=cut 59 60sub prototype 61{ 62 my ( $code ) = @_; 63 return CORE::prototype( $code ); 64} 65 66=head2 set_prototype 67 68 my $code = set_prototype $prototype, $code; 69 70I<Since version 1.40.> 71 72Sets the prototype of the function given by the C<$code> reference, or deletes 73it if C<$prototype> is C<undef>. Returns the C<$code> reference itself. 74 75I<Caution>: This function takes arguments in a different order to the previous 76copy of the code from C<Scalar::Util>. This is to match the order of 77C<set_subname>, and other potential additions in this file. This order has 78been chosen as it allows a neat and simple chaining of other 79C<Sub::Util::set_*> functions as might become available, such as: 80 81 my $code = 82 set_subname name_here => 83 set_prototype '&@' => 84 set_attribute ':lvalue' => 85 sub { ...... }; 86 87=cut 88 89=head2 subname 90 91 my $name = subname( $code ) 92 93I<Since version 1.40.> 94 95Returns the name of the given C<$code> reference, if it has one. Normal named 96subs will give a fully-qualified name consisting of the package and the 97localname separated by C<::>. Anonymous code references will give C<__ANON__> 98as the localname. If a name has been set using L</set_subname>, this name will 99be returned instead. 100 101This function was inspired by C<sub_fullname> from L<Sub::Identify>. The 102remaining functions that C<Sub::Identify> implements can easily be emulated 103using regexp operations, such as 104 105 sub get_code_info { return (subname $_[0]) =~ m/^(.+)::(.*?)$/ } 106 sub sub_name { return (get_code_info $_[0])[0] } 107 sub stash_name { return (get_code_info $_[0])[1] } 108 109I<Users of Sub::Name beware>: This function is B<not> the same as 110C<Sub::Name::subname>; it returns the existing name of the sub rather than 111changing it. To set or change a name, see instead L</set_subname>. 112 113=cut 114 115=head2 set_subname 116 117 my $code = set_subname $name, $code; 118 119I<Since version 1.40.> 120 121Sets the name of the function given by the C<$code> reference. Returns the 122C<$code> reference itself. If the C<$name> is unqualified, the package of the 123caller is used to qualify it. 124 125This is useful for applying names to anonymous CODE references so that stack 126traces and similar situations, to give a useful name rather than having the 127default of C<__ANON__>. Note that this name is only used for this situation; 128the C<set_subname> will not install it into the symbol table; you will have to 129do that yourself if required. 130 131However, since the name is not used by perl except as the return value of 132C<caller>, for stack traces or similar, there is no actual requirement that 133the name be syntactically valid as a perl function name. This could be used to 134attach extra information that could be useful in debugging stack traces. 135 136This function was copied from C<Sub::Name::subname> and renamed to the naming 137convention of this module. 138 139=cut 140 141=head1 AUTHOR 142 143The general structure of this module was written by Paul Evans 144<leonerd@leonerd.org.uk>. 145 146The XS implementation of L</set_subname> was copied from L<Sub::Name> by 147Matthijs van Duin <xmath@cpan.org> 148 149=cut 150 1511; 152