NAME

       Sub::Util - A selection of utility subroutines for subs and CODE references

SYNOPSIS

           use Sub::Util qw( prototype set_prototype subname set_subname );

DESCRIPTION

       "Sub::Util" contains a selection of utility subroutines that are useful for operating on
       subs and CODE references.

       The rationale for inclusion in this module is that the function performs some work for
       which an XS implementation is essential because it cannot be implemented in Pure Perl, and
       which is sufficiently-widely used across CPAN that its popularity warrants inclusion in a
       core module, which this is.

FUNCTIONS

   prototype
           my $proto = prototype( $code )

       Since version 1.40.

       Returns the prototype of the given $code reference, if it has one, as a string. This is
       the same as the "CORE::prototype" operator; it is included here simply for symmetry and
       completeness with the other functions.

   set_prototype
           my $code = set_prototype $prototype, $code;

       Since version 1.40.

       Sets the prototype of the function given by the $code reference, or deletes it if
       $prototype is "undef". Returns the $code reference itself.

       Caution: This function takes arguments in a different order to the previous copy of the
       code from "Scalar::Util". This is to match the order of "set_subname", and other potential
       additions in this file. This order has been chosen as it allows a neat and simple chaining
       of other "Sub::Util::set_*" functions as might become available, such as:

        my $code =
           set_subname   name_here =>
           set_prototype '&@'      =>
           set_attribute ':lvalue' =>
              sub { ...... };

   subname
           my $name = subname( $code )

       Since version 1.40.

       Returns the name of the given $code reference, if it has one. Normal named subs will give
       a fully-qualified name consisting of the package and the localname separated by "::".
       Anonymous code references will give "__ANON__" as the localname. If a name has been set
       using "set_subname", this name will be returned instead.

       This function was inspired by "sub_fullname" from Sub::Identify. The remaining functions
       that "Sub::Identify" implements can easily be emulated using regexp operations, such as

        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] }

       Users of Sub::Name beware: This function is not the same as "Sub::Name::subname"; it
       returns the existing name of the sub rather than changing it. To set or change a name, see
       instead "set_subname".

   set_subname
           my $code = set_subname $name, $code;

       Since version 1.40.

       Sets the name of the function given by the $code reference. Returns the $code reference
       itself. If the $name is unqualified, the package of the caller is used to qualify it.

       This is useful for applying names to anonymous CODE references so that stack traces and
       similar situations, to give a useful name rather than having the default of "__ANON__".
       Note that this name is only used for this situation; the "set_subname" will not install it
       into the symbol table; you will have to do that yourself if required.

       However, since the name is not used by perl except as the return value of "caller", 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.

       This function was copied from "Sub::Name::subname" and renamed to the naming convention of
       this module.

AUTHOR

       The general structure of this module was written by Paul Evans <leonerd@leonerd.org.uk>.

       The XS implementation of "set_subname" was copied from Sub::Name by Matthijs van Duin
       <xmath@cpan.org>