Method: Factbase::Query#each

Defined in:
lib/factbase/query.rb

#each(fb = @fb, params = {}) {|Fact| ... } ⇒ Integer

Iterate facts one by one.

Parameters:

  • fb (Factbase) (defaults to: @fb) —

    The factbase

  • params (Hash) (defaults to: {}) —

    Optional params accessible in the query via the “$” symbol

Yields:

  • (Fact) —

    Facts one-by-one

Returns:

  • (Integer) —

    Total number of facts yielded (if block given), otherwise enumerator



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# File 'lib/factbase/query.rb', line 45

def each(fb = @fb, params = {})
  return to_enum(__method__, fb, params) unless block_given?
  yielded = 0
  params = params.transform_keys(&:to_s) if params.is_a?(Hash)
  maybe = @term.predict(@maps, fb, Factbase::Tee.new({}, params))
  maybe ||= @maps unless maybe.equal?(@maps)
  maybe.each do |m|
    extras = {}
    f = Factbase::Fact.new(m)
    f = Factbase::Tee.new(f, params)
    a = Factbase::Accum.new(f, extras, false)
    r = @term.evaluate(a, @maps, fb)
    unless r.is_a?(TrueClass) || r.is_a?(FalseClass)
      raise "Unexpected evaluation result of type #{r.class}, must be Boolean at #{@term.inspect}"
    end
    next unless r
    yield Factbase::Accum.new(f, extras, true)
    yielded += 1
  end
  yielded
end