Class: Factbase::Nil

Inherits:

TermBase

• Object
• TermBase
• Factbase::Nil

Defined in:

lib/factbase/terms/nil.rb

Overview

A class representing a "nil" term in the Factbase system. It evaluates to true if the value is nil.

Instance Method Summary

• #evaluate(fact, maps, fb) ⇒ Boolean

  Evaluate term on a fact.

• #initialize(operands) ⇒ Nil constructor

  Constructor.

Constructor Details

#initialize(operands) ⇒ Nil

Constructor.

Parameters:

• operands (Array) —

  Operands

# File 'lib/factbase/terms/nil.rb', line 12

def initialize(operands)
  super()
  @operands = operands
end

Instance Method Details

#evaluate(fact, maps, fb) ⇒ Boolean

Evaluate term on a fact.

Parameters:

• fact (Factbase::Fact) —

  The fact

• maps (Array<Factbase::Fact>) —

  All maps available

• fb (Factbase) —

  Factbase to use for sub-queries

Returns:

• (Boolean) —

  True if nil

# File 'lib/factbase/terms/nil.rb', line 22

def evaluate(fact, maps, fb)
  assert_args(1)
  _values(0, fact, maps, fb).nil?
end