module DataModel
	# Boolean type
	class Builtin::Boolean < Type
		include Errors

		# Arguments for the boolean type
		class Arguments < Struct
			prop :optional, :boolean, default: false
		end

		# read a value, and validate it
		# @param val [Object] the value to read
		# @param coerce [Boolean] whether to coerce the value
		# @return [Array(Object, Error)] the result of reading the value
		def read(val, coerce: false)
			err = Error.new

			if val.nil?
				err.add(missing_error(type_name))
				return [val, err]
			end

			if coerce
				case val
				when "true"
					val = true
				when "false"
					val = false
				end
			end

			if !val.is_a?(TrueClass) && !val.is_a?(FalseClass)
				err.add(type_error(type_name, val))
				return [val, err]
			end

			return [val, err]
		end
	end
end