.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.40) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Sub::Util 3perl" .TH Sub::Util 3perl "2021-09-24" "perl v5.32.1" "Perl Programmers Reference Guide" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Sub::Util \- A selection of utility subroutines for subs and CODE references .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& use Sub::Util qw( prototype set_prototype subname set_subname ); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" \&\f(CW\*(C`Sub::Util\*(C'\fR contains a selection of utility subroutines that are useful for operating on subs and \s-1CODE\s0 references. .PP The rationale for inclusion in this module is that the function performs some work for which an \s-1XS\s0 implementation is essential because it cannot be implemented in Pure Perl, and which is sufficiently-widely used across \s-1CPAN\s0 that its popularity warrants inclusion in a core module, which this is. .SH "FUNCTIONS" .IX Header "FUNCTIONS" .SS "prototype" .IX Subsection "prototype" .Vb 1 \& my $proto = prototype( $code ) .Ve .PP \&\fISince version 1.40.\fR .PP Returns the prototype of the given \f(CW$code\fR reference, if it has one, as a string. This is the same as the \f(CW\*(C`CORE::prototype\*(C'\fR operator; it is included here simply for symmetry and completeness with the other functions. .SS "set_prototype" .IX Subsection "set_prototype" .Vb 1 \& my $code = set_prototype $prototype, $code; .Ve .PP \&\fISince version 1.40.\fR .PP Sets the prototype of the function given by the \f(CW$code\fR reference, or deletes it if \f(CW$prototype\fR is \f(CW\*(C`undef\*(C'\fR. Returns the \f(CW$code\fR reference itself. .PP \&\fICaution\fR: This function takes arguments in a different order to the previous copy of the code from \f(CW\*(C`Scalar::Util\*(C'\fR. This is to match the order of \&\f(CW\*(C`set_subname\*(C'\fR, and other potential additions in this file. This order has been chosen as it allows a neat and simple chaining of other \&\f(CW\*(C`Sub::Util::set_*\*(C'\fR functions as might become available, such as: .PP .Vb 5 \& my $code = \& set_subname name_here => \& set_prototype \*(Aq&@\*(Aq => \& set_attribute \*(Aq:lvalue\*(Aq => \& sub { ...... }; .Ve .SS "subname" .IX Subsection "subname" .Vb 1 \& my $name = subname( $code ) .Ve .PP \&\fISince version 1.40.\fR .PP Returns the name of the given \f(CW$code\fR reference, if it has one. Normal named subs will give a fully-qualified name consisting of the package and the localname separated by \f(CW\*(C`::\*(C'\fR. Anonymous code references will give \f(CW\*(C`_\|_ANON_\|_\*(C'\fR as the localname. If the package the code was compiled in has been deleted (e.g. using \f(CW\*(C`delete_package\*(C'\fR from Symbol), \f(CW\*(C`_\|_ANON_\|_\*(C'\fR will be returned as the package name. If a name has been set using \*(L"set_subname\*(R", this name will be returned instead. .PP This function was inspired by \f(CW\*(C`sub_fullname\*(C'\fR from Sub::Identify. The remaining functions that \f(CW\*(C`Sub::Identify\*(C'\fR implements can easily be emulated using regexp operations, such as .PP .Vb 3 \& sub get_code_info { return (subname $_[0]) =~ m/^(.+)::(.*?)$/ } \& sub sub_name { return (get_code_info $_[0])[0] } \& sub stash_name { return (get_code_info $_[0])[1] } .Ve .PP \&\fIUsers of Sub::Name beware\fR: This function is \fBnot\fR the same as \&\f(CW\*(C`Sub::Name::subname\*(C'\fR; it returns the existing name of the sub rather than changing it. To set or change a name, see instead \*(L"set_subname\*(R". .SS "set_subname" .IX Subsection "set_subname" .Vb 1 \& my $code = set_subname $name, $code; .Ve .PP \&\fISince version 1.40.\fR .PP Sets the name of the function given by the \f(CW$code\fR reference. Returns the \&\f(CW$code\fR reference itself. If the \f(CW$name\fR is unqualified, the package of the caller is used to qualify it. .PP This is useful for applying names to anonymous \s-1CODE\s0 references so that stack traces and similar situations, to give a useful name rather than having the default of \f(CW\*(C`_\|_ANON_\|_\*(C'\fR. Note that this name is only used for this situation; the \f(CW\*(C`set_subname\*(C'\fR will not install it into the symbol table; you will have to do that yourself if required. .PP However, since the name is not used by perl except as the return value of \&\f(CW\*(C`caller\*(C'\fR, for stack traces or similar, there is no actual requirement that the name be syntactically valid as a perl function name. This could be used to attach extra information that could be useful in debugging stack traces. .PP This function was copied from \f(CW\*(C`Sub::Name::subname\*(C'\fR and renamed to the naming convention of this module. .SH "AUTHOR" .IX Header "AUTHOR" The general structure of this module was written by Paul Evans . .PP The \s-1XS\s0 implementation of \*(L"set_subname\*(R" was copied from Sub::Name by Matthijs van Duin