Contents

# frozen_string_literal: true

module God
  module Conditions
    class Complex < PollCondition
      AND = 0x1
      OR  = 0x2
      NOT = 0x4

      def initialize
        super

        @oper_stack = []
        @op_stack = []

        @this = nil
      end

      def valid?
        @oper_stack.inject(true) { |acc, oper| acc & oper.valid? }
      end

      def prepare
        @oper_stack.each(&:prepare)
      end

      def new_oper(kind, operand)
        oper = Condition.generate(kind, watch)
        @oper_stack.push(oper)
        @op_stack.push(operand)
        oper
      end

      def this(kind)
        @this = Condition.generate(kind, watch)
        yield @this if block_given?
      end

      def and(kind)
        oper = new_oper(kind, 0x1)
        yield oper if block_given?
      end

      def and_not(kind)
        oper = new_oper(kind, 0x5)
        yield oper if block_given?
      end

      def or(kind)
        oper = new_oper(kind, 0x2)
        yield oper if block_given?
      end

      def or_not(kind)
        oper = new_oper(kind, 0x6)
        yield oper if block_given?
      end

      def test
        res = if @this.nil?
                # Although this() makes sense semantically and therefore
                # encourages easy-to-read conditions, being able to omit it
                # allows for more DRY code in some cases, so we deal with a
                # nil @this here by initially setting res to true or false,
                # depending on whether the first operator used is AND or OR
                # respectively.
                @op_stack[0] & AND > 0
              else
                @this.test
              end

        @op_stack.each do |op|
          cond = @oper_stack.shift
          value = op & NOT > 0 ? !cond.test : cond.test
          if op & AND > 0
            res &&= value
          else
            res ||= value
          end
          @oper_stack.push cond
        end

        res
      end
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
resurrected_god-1.1.1	lib/god/conditions/complex.rb
resurrected_god-1.1.0	lib/god/conditions/complex.rb