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NAME

Devel::Hints - Access compile-time hints at runtime

VERSION

This document describes version 0.11 of Devel::Hints, released December 30, 2005.

SYNOPSIS

    use Devel::Hints ':all';

    LABEL:
    print cop_label();      # 'LABEL'
    cop_label(0 => 'FOO');  # "goto FOO;" is valid after this point!
    print cop_file();       # same as __FILE__
    print cop_filegv();     # same as \$::{'_<' . __FILE__}
    print cop_stashpv();    # same as __PACKAGE__
    print cop_stash();      # same as \%{__PACKAGE__ . '::'}
    print cop_seq();        # an integer
    print cop_arybase();    # same as $[
    print cop_line();       # same as __LINE__

    use warnings;
    print cop_warnings();   # same as compile-time ${^WARNING_BITS}

    # cop_io() is only available to Perl 5.7 or above
    use open IO => ':utf8';
    print cop_io();         # same as compile-time ${^OPEN}

    {
        use IO => ':raw';
        print cop_io(1);    # access one uplevel; still ":utf8\0:utf8"
    }

DESCRIPTION

This module exports the cop (code operator) struct as individual functions; callers can call them to find out the lexical-scoped hints that its block (or statement) is compiled under.

No functions are exported by default. Each function may take an optional positive integer as argument, indicating how many blocks it should walk upward to obtain the cop members.

Functions can also take another optional argument, which (if specified) becomes the new value for the hint, affecting the current statement or block's behaviour.

FUNCTIONS

cop_label

Label for the current construct.

cop_file

File name for the current source file.

cop_filegv

Glob reference to the current source filehandle.

cop_stashpv

The current package name.

cop_stash

Hash reference to the current symbol table.

cop_seq

Parse sequencial number.

cop_arybase

Array base the calling line was compiled with.

cop_line

The line number.

cop_warnings

Lexical warnings bitmask, a.k.a. ${^WARNING_BITS}. If no lexical warnings are in effect, returns the global warning flags as an integer.

cop_io

Lexical IO defaults, a.k.a. ${^OPEN}. If no lexical IO layers are in effect, an empty string is returned. Always returns undef under pre-5.7 versions of Perl.

ACKNOWLEDGMENTS

Thanks to Rafael Garcia-Suarez for demonstrating how to do this with the elegant Inline::C code on p5p, which I adapted to this less elegant XS implementation.

AUTHORS

Audrey Tang <autrijus@autrijus.org>

COPYRIGHT

Copyright 2003, 2005 by Audrey Tang <autrijus@autrijus.org>.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

See http://www.perl.com/perl/misc/Artistic.html