NAME

       autodie::Util - Internal Utility subroutines for autodie and Fatal

SYNOPSIS

           # INTERNAL API for autodie and Fatal only!

           use autodie::Util qw(on_end_of_compile_scope);
           on_end_of_compile_scope(sub { print "Hallo world\n"; });

DESCRIPTION

       Interal Utilities for autodie and Fatal!  This module is not a part of autodie's public
       API.

       This module contains utility subroutines for abstracting away the underlying magic of
       autodie and (ab)uses of "%^H" to call subs at the end of a (compile-time) scopes.

       Note that due to how "%^H" works, some of these utilities are only useful during the
       compilation phase of a perl module and relies on the internals of how perl handles
       references in "%^H".

   Methods
       on_end_of_compile_scope

         on_end_of_compile_scope(sub { print "Hallo world\n"; });

       Will invoke a sub at the end of a (compile-time) scope.  The sub is called once with no
       arguments.  Can be called multiple times (even in the same "compile-time" scope) to
       install multiple subs.  Subs are called in a "first-in-last-out"-order (FILO or
       "stack"-order).

       fill_protos

         fill_protos('*$$;$@')

       Given a Perl subroutine prototype, return a list of invocation specifications.  Each
       specification is a listref, where the first member is the (minimum) number of arguments
       for this invocation specification.  The remaining arguments are a string representation of
       how to pass the arguments correctly to a sub with the given prototype, when called with
       the given number of arguments.

       The specifications are returned in increasing order of arguments starting at 0 (e.g.
       ';$') or 1 (e.g.  '$@').  Note that if the prototype is "slurpy" (e.g. ends with a "@"),
       the number of arguments for the last specification is a "minimum" number rather than an
       exact number.  This can be detected by the last member of the last specification matching
       m/[@#]_/.

       make_core_trampoline

         make_core_trampoline('CORE::open', 'main', prototype('CORE::open'))

       Creates a trampoline for calling a core sub.  Essentially, a tiny sub that figures out how
       we should be calling our core sub, puts in the arguments in the right way, and bounces our
       control over to it.

       If we could reliably use `goto &` on core builtins, we wouldn't need this subroutine.

       install_subs

         install_subs('My::Module', { 'read' => sub { die("Hallo\n"), ... }})

       Given a package name and a hashref mapping names to a subroutine reference (or "undef"),
       this subroutine will install said subroutines on their given name in that module.  If a
       name mapes to "undef", any subroutine with that name in the target module will be remove
       (possibly "unshadowing" a CORE sub of same name).

AUTHOR

       Copyright 2013-2014, Niels Thykier <niels@thykier.net>

LICENSE

       This module is free software.  You may distribute it under the same terms as Perl itself.