Class: Factbase::Unique

Inherits:

TermBase

• Object
• TermBase
• Factbase::Unique

Defined in:

lib/factbase/terms/unique.rb

Overview

of terms based on provided operands and facts.

Instance Method Summary

• #evaluate(fact, maps, fb) ⇒ Boolean

  Evaluate term on a fact.

• #initialize(operands) ⇒ Unique constructor

  Constructor.

Methods inherited from TermBase

#to_s

Constructor Details

#initialize(operands) ⇒ Unique

Constructor.

Parameters:

• operands (Array) —

  Operands

# File 'lib/factbase/terms/unique.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 the value is unique, false otherwise

Raises:

• (ArgumentError)

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

def evaluate(fact, maps, fb)
  @seen = Set.new if @seen.nil?
  raise(ArgumentError, "Too few operands for 'unique' (at least 1 expected)") if @operands.empty?
  vv = (0..(@operands.size - 1)).map { |i| _values(i, fact, maps, fb) }
  return false if vv.any?(nil)
  tuples = Enumerator.product(*vv).to_a
  tuples.none? { |t| @seen.include?(t) }.tap { tuples.each { |t| @seen << t } }
end