Pod::Simple::Debug - put Pod::Simple into trace/debug mode


Pod-Simple documentation Contained in the Pod-Simple distribution.

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NAME

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Pod::Simple::Debug -- put Pod::Simple into trace/debug mode

SYNOPSIS

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 use Pod::Simple::Debug (5);  # or some integer

Or:

 my $debuglevel;
 use Pod::Simple::Debug (\$debuglevel, 0);
 ...some stuff that uses Pod::Simple to do stuff, but which
  you don't want debug output from...

 $debug_level = 4;
 ...some stuff that uses Pod::Simple to do stuff, but which
  you DO want debug output from...

 $debug_level = 0;

DESCRIPTION

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This is an internal module for controlling the debug level (a.k.a. trace level) of Pod::Simple. This is of interest only to Pod::Simple developers.

CAVEATS

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Note that you should load this module before loading Pod::Simple (or any Pod::Simple-based class). If you try loading Pod::Simple::Debug after &Pod::Simple::DEBUG is already defined, Pod::Simple::Debug will throw a fatal error to the effect that "it's s too late to call Pod::Simple::Debug".

Note that the use Pod::Simple::Debug (\$x, somenum) mode will make Pod::Simple (et al) run rather slower, since &Pod::Simple::DEBUG won't be a constant sub anymore, and so Pod::Simple (et al) won't compile with constant-folding.

GUTS

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Doing this:

  use Pod::Simple::Debug (5);  # or some integer

is basically equivalent to:

  BEGIN { sub Pod::Simple::DEBUG () {5} }  # or some integer
  use Pod::Simple ();

And this:

  use Pod::Simple::Debug (\$debug_level,0);  # or some integer

is basically equivalent to this:

  my $debug_level;
  BEGIN { $debug_level = 0 }
  BEGIN { sub Pod::Simple::DEBUG () { $debug_level }
  use Pod::Simple ();

SEE ALSO

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Pod::Simple

The article "Constants in Perl", in The Perl Journal issue 21. See http://interglacial.com/tpj/21/

SUPPORT

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Questions or discussion about POD and Pod::Simple should be sent to the pod-people@perl.org mail list. Send an empty email to pod-people-subscribe@perl.org to subscribe.

This module is managed in an open GitHub repository, http://github.com/theory/pod-simple/. Feel free to fork and contribute, or to clone git://github.com/theory/pod-simple.git and send patches!

Patches against Pod::Simple are welcome. Please send bug reports to <bug-pod-simple@rt.cpan.org>.

COPYRIGHT AND DISCLAIMERS

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AUTHOR

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Pod::Simple was created by Sean M. Burke <sburke@cpan.org>. But don't bother him, he's retired.

Pod::Simple is maintained by:

* Allison Randal allison@perl.org
* Hans Dieter Pearcey hdp@cpan.org
* David E. Wheeler dwheeler@cpan.org

Pod-Simple documentation Contained in the Pod-Simple distribution.

require 5;
package Pod::Simple::Debug;
use strict;
use vars qw($VERSION );
$VERSION = '3.16';

sub import {
  my($value,$variable);
  
  if(@_ == 2) {
    $value = $_[1];
  } elsif(@_ == 3) {
    ($variable, $value) = @_[1,2];
    
    ($variable, $value) = ($value, $variable)
       if     defined $value    and ref($value)    eq 'SCALAR'
      and not(defined $variable and ref($variable) eq 'SCALAR')
    ; # tolerate getting it backwards
    
    unless( defined $variable and ref($variable) eq 'SCALAR') {
      require Carp;
      Carp::croak("Usage:\n use Pod::Simple::Debug (NUMVAL)\nor"
                . "\n use Pod::Simple::Debug (\\\$var, STARTNUMVAL)\nAborting");
    }
  } else {
    require Carp;
    Carp::croak("Usage:\n use Pod::Simple::Debug (NUMVAL)\nor"
                    . "\n use Pod::Simple::Debug (\\\$var, STARTNUMVAL)\nAborting");
  }

  if( defined &Pod::Simple::DEBUG ) {
    require Carp;
    Carp::croak("It's too late to call Pod::Simple::Debug -- "
              . "Pod::Simple has already loaded\nAborting");
  }
  
  $value = 0 unless defined $value;

  unless($value =~ m/^-?\d+$/) {
    require Carp;
    Carp::croak( "$value isn't a numeric value."
            . "\nUsage:\n use Pod::Simple::Debug (NUMVAL)\nor"
                    . "\n use Pod::Simple::Debug (\\\$var, STARTNUMVAL)\nAborting");
  }

  if( defined $variable ) {
    # make a not-really-constant
    *Pod::Simple::DEBUG = sub () { $$variable } ;
    $$variable = $value;
    print "# Starting Pod::Simple::DEBUG = non-constant $variable with val $value\n";
  } else {
    *Pod::Simple::DEBUG = eval " sub () { $value } ";
    print "# Starting Pod::Simple::DEBUG = $value\n";
  }
  
  require Pod::Simple;
  return;
}

1;


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