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Sub::Util cpan:ELIZABETH last updated on 2018-04-25


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Sub::Util - Port of Perl 5's Sub::Util 1.49


use Sub::Util <subname set_subname>


Sub::Util contains a selection of subroutines that people have expressed would be nice to have in the perl core, but the usage would not really be high enough to warrant the use of a keyword, and the size would be so small that being individual extensions would be wasteful.

By default Sub::Util does not export any subroutines.


my $name = subname( $callable );

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

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.


my $callable = set_subname $name, $callable;

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

This is useful for applying names to anonymous Callables so that stack traces and similar situations, to give a useful name rather than having the default. 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.


It did not make sense to port the following functions to Perl 6, as they pertain to specific Pumpkin Perl 5 internals.

prototype set_prototype

Attempting to import these functions will result in a compilation error with hopefully targeted feedback. Attempt to call these functions using the fully qualified name (e.g. Sub::Util::set_prototype($a)) will result in a run time error with the same feedback.




Elizabeth Mattijsen [email protected]

Source can be located at: . Comments and Pull Requests are welcome.


Copyright 2018 Elizabeth Mattijsen

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.

Re-imagined from the Perl 5 version as part of the CPAN Butterfly Plan. Perl 5 version originally developed by Paul Evans.