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Diffstat (limited to 'Master/tlpkg/tlperl/lib/CORE.pod')
-rw-r--r-- | Master/tlpkg/tlperl/lib/CORE.pod | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/Master/tlpkg/tlperl/lib/CORE.pod b/Master/tlpkg/tlperl/lib/CORE.pod index c917bba44a0..ec6a8047a4d 100644 --- a/Master/tlpkg/tlperl/lib/CORE.pod +++ b/Master/tlpkg/tlperl/lib/CORE.pod @@ -1,6 +1,6 @@ =head1 NAME -CORE - Pseudo-namespace for Perl's core routines +CORE - Namespace for Perl's core routines =head1 SYNOPSIS @@ -10,16 +10,40 @@ CORE - Pseudo-namespace for Perl's core routines print hex("0x50"),"\n"; # prints 1 print CORE::hex("0x50"),"\n"; # prints 80 + CORE::say "yes"; # prints yes + + BEGIN { *shove = \&CORE::push; } + shove @array, 1,2,3; # pushes on to @array =head1 DESCRIPTION The C<CORE> namespace gives access to the original built-in functions of -Perl. There is no C<CORE> package, and therefore you do not need to use or -require an hypothetical "CORE" module prior to accessing routines in this +Perl. The C<CORE> package is built into +Perl, and therefore you do not need to use or +require a hypothetical "CORE" module prior to accessing routines in this namespace. A list of the built-in functions in Perl can be found in L<perlfunc>. +For all Perl keywords, a C<CORE::> prefix will force the built-in function +to be used, even if it has been overridden or would normally require the +L<feature> pragma. Despite appearances, this has nothing to do with the +CORE package, but is part of Perl's syntax. + +For many Perl functions, the CORE package contains real subroutines. This +feature is new in Perl 5.16. You can take references to these and make +aliases. However, some can only be called as barewords; i.e., you cannot +use ampersand syntax (C<&foo>) or call them through references. See the +C<shove> example above. These subroutines exist for all overridable +keywords, except for C<dump> and the infix operators. Calling with +ampersand syntax and through references does not work for the following +functions, as they have special syntax that cannot always be translated +into a simple list (e.g., C<eof> vs C<eof()>): + +C<chdir>, C<chomp>, C<chop>, C<each>, C<eof>, C<exec>, C<keys>, C<lstat>, +C<pop>, C<push>, C<shift>, C<splice>, C<stat>, C<system>, C<truncate>, +C<unlink>, C<unshift>, C<values> + =head1 OVERRIDING CORE FUNCTIONS To override a Perl built-in routine with your own version, you need to |