2. Manual Importing and Exporting

Constants

• Now we'll see how use constant works

         sub import {
           my $name = shift or return;       
           my $value = shift;

           my $caller = caller;
           *{$caller . "::$name"} = sub () { $value };
         }

• The caller can say

         use constant PI => 3;

         $circumference = 2 * PI * $r;

• Real module has error checking, list constants, etc.

• Real module also loads 1289 lines of code!

  • (Up 18% since 1998)

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Copyright © 2002 M-J. Dominus