NAME

pragma - A pragma for controlling other user pragmas

DESCRIPTION

The pragma pragma is a module which influences other user pragmata such as lint. With Perl 5.10 you can create user pragmata and the pragma pragma can modify and peek at other pragmata.

A basic example

Assume you're using the myint pragma mentioned in perlpragma. For ease, that pragma is duplicated here. You'll see it sets the myint value to 1 when on and 0 when off.

package myint;

use strict;
use warnings;

sub import {
    $^H{myint} = 1;
}

sub unimport {
    $^H{myint} = 0;
}

1;

Other code might casually wish to dip into myint:

no pragma 'myint';      # delete $^H{myint}
use pragma myint => 42; # $^H{myint} = 42

print pragma->peek( 'myint' ); # prints '42'

The above could have been written without the pragma module as:

BEGIN { delete $^H{myint} }
BEGIN { $^H{myint} = 42 }

print $^H{myint};

CLASS METHODS

use pragma PRAGMA => VALUE

pragma->import( PRAGMA => VALUE )

pragma->poke( PRAGMA => VALUE )

Sets PRAGMA's value to VALUE.

no pragma PRAGMA

pragma->unimport( PRAGMA )

Unsets PRAGMA.

pragma->peek( PRAGMA )

Returns the current value of PRAGMA.

SUBCLASSING

All methods may be subclassed.