Tie_Scalar

# NAME

Tie::Scalar, Tie::StdScalar - base class definitions for tied scalars

# SYNOPSIS

        package NewScalar;
        require Tie::Scalar;

        @ISA = (Tie::Scalar);

        sub FETCH { ... }           # Provide a needed method
        sub TIESCALAR { ... }       # Overrides inherited method

        package NewStdScalar;
        require Tie::Scalar;

        @ISA = (Tie::StdScalar);

        # All methods provided by default, so define only what needs be overridden
        sub FETCH { ... }

        package main;

        tie $new_scalar, NewScalar;
        tie $new_std_scalar, NewStdScalar;

# DESCRIPTION

This module provides some skeletal methods for scalar-tying classes. See the perltie manpage for a list of the functions required in tying a scalar to a package. The basic Tie::Scalar package provides a `new` method, as well as methods TIESCALAR , FETCH and STORE . The Tie::StdScalar package provides all the methods specified in the perltie manpage . It inherits from Tie::Scalar and causes scalars tied to it to behave exactly like the built-in scalars, allowing for selective overloading of methods. The `new` method is provided as a means of grandfathering, for classes that forget to provide their own TIESCALAR method.

For developers wishing to write their own tied-scalar classes, the methods are summarized below. The the perltie manpage section not only documents these, but has sample code as well:

TIESCALAR classname, LIST
  The method invoked by the command tie $scalar, classname . Associates a new scalar instance with the specified class. `LIST` would represent additional arguments (along the lines of AnyDBM_File and compatriots) needed to complete the association.

FETCH this
  Retrieve the value of the tied scalar referenced by this.

STORE this, value
  Store data value in the tied scalar referenced by this.

DESTROY this
  Free the storage associated with the tied scalar referenced by this. This is rarely needed, as Perl manages its memory quite well. But the option exists, should a class wish to perform specific actions upon the destruction of an instance.

# MORE INFORMATION

The the perltie manpage section uses a good example of tying scalars by associating process IDs with priority.