NAME

Function::Register - Create Function Registries and Register Functions

SYNOPSIS

  package Company::Employee;
  use Function::Register;
  set_register 'Type';
  
  sub employee_type {
      my $self = shift;
      for ( @Type ) {
          my $retval = $_->($self);
          return $retval if $retval;
      }
      return;
  }


  # meanwhile, in some other package
  package Company::Employee::Executive;
  use Function::Register 'Company::Employee';

  register Type => \&is_cto;
  register Type => \&is_ceo;
  
  sub is_cto { ... }
  sub is_ceo { ... }

  # meanwhile, in your program
  use Company::Employee;
  use Company::Employee::Executive;
  
  my $employee = Company::Employee->new( title => "CEO", ... );
  print $employee->employee_type;

DESCRIPTION

This module allows you to declare registers in your namespace, and update registers in other modules.

Exports

There are two ways to use this modules.

As the Registry

  use Function::Register;

As the registry you simply use the module without any arguments. This will export the set_register function. It will also create a default register in your namespace called @REGISTER.

As the Registrant

  use Function::Register qw[Some::NameSpace];

As the registrant you use the module with a single argument. This will export the register function. It will remember what namespace you want to add to each time you call register.

Functions

set_registry

  set_registry 'Name';

This function creates a new register in your namespace. A register is a package array of the same name. The call above creates an array, @Name, in your namespace.

register

  register sub { ... };
  register Name => \&function_ref;

This function registeres functions in the namespace you've declared as your registrant. If a single argument is given the function is added to the default registry. If two arguments are given, the first is the name of of the register and the second is a function.

This function returns a false value if it was unable to add the function to the register. This may be because the register name does not exist, or the function argument isn't a code reference.

If register is successful it returns true.

  die "Couldn't add to register"
    unless register \&some_func;

SEE ALSO

For a more OO and "do it all for me behind my back" approach, see Module::Pluggable.

perl.

AUTHOR

Casey West, <casey@geeknest.com>.

COPYRIGHT

  Copyright (c) 2004 Casey West.  All rights reserved.
  This module is free software; you can redistribute it and/or modify it
  under the same terms as Perl itself.