class Sus::BeWithin

def call(assertions, subject)
	assertions.nested(self) do |assertions|
		assertions.assert(subject < @tolerance, self)
	end
end

def initialize(tolerance)
	@tolerance = tolerance
end

def of(value)
	tolerance = @tolerance.abs
	
	return Bounded.new(Range.new(value - tolerance, value + tolerance))
end

def percent_of(value)
	tolerance = Rational(@tolerance, 100)
	
	return Bounded.new(Range.new(value - value * tolerance, value + value * tolerance))
end

def print(output)
	output.write("be within ", :variable, @tolerance, :reset)
end