Class: SleepingKingStudios::Tools::Undefined

Parent Namespace

SleepingKingStudios::Tools

Defined In

lib/sleeping_king_studios/tools/undefined.rb

Table Of Contents

• Overview
  • Examples
• Instance Methods
  • inspect
  • instance_of?
  • is_a?

Overview

Immutable empty object used to represent undefined method parameters.

Use an instance of Undefined as a value object to distinguish between an optional method parameter that is passed a nil value from a method parameter that is not passed.

Examples

UNDEFINED = Undefined.new
private_constant :UNDEFINED

def parameter_passed?(parameter = UNDEFINED)
  parameter != UNDEFINED
end

parameter_passed?      #=> false
parameter_passed?(nil) #=> true

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Instance Methods

#inspect => String

Returns

• (String) — a string containing a human-readable representation of the object.

#instance_of?(mod) => true, false

Parameters

• mod (Module) — the class or module to compare.

Returns

• (true, false) — true if the object is an instance of the given class.

#is_a?(mod) => true, false

Also known as: kind_of?

Parameters

• mod (Module) — the class or module to compare.

Returns

• (true, false) — true if the given class is an ancestor of the object.

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