File: once.rb

Do something only once. Called this way:

 once('variable-name') { block }

*variable-name* is a string. The corresponding variable is referenced within the block‘s binding using eval().

If the variable doesn‘t exist, or if it‘s false or nil:

      The block is executed.
      The variable is set to true, within the block's binding.
      True is returned.

If the variable is true:

      False is returned.

Although this will by default create a simple boolean, more complex variables such as object.method calls, array and hash references work fine. I‘ve used it effectively with 2-dimensional hashes.

Methods

once

Public Instance methods

once(var) {|| ...}

Do something only once. Called this way:

 once('variable-name') { block }

*variable-name* is a string. The corresponding variable is referenced within the block‘s binding using eval().

If the variable doesn‘t exist, or if it‘s false or nil:

      The block is executed.
      The variable is set to true, within the block's binding.
      True is returned.

If the variable is true:

      False is returned.

Although this will by default create a simple boolean, more complex variables such as object.method calls, array and hash references work fine. I‘ve used it effectively with 2-dimensional hashes.