redef fun to_i
	do
		assert self.is_int
		var s = remove_all('_')
		var val = 0
		var neg = false
		var pos = 0
		loop
			if s[pos] == '-' then
				neg = not neg
				pos += 1
			else if s[pos] == '+' then
				pos += 1
			else
				break
			end
		end
		s = s.substring_from(pos)
		if s.length >= 2 then
			var s1 = s[1]
			if s1 == 'x' or s1 == 'X' then
				val = s.substring_from(2).to_hex
			else if s1 == 'o' or s1 == 'O' then
				val = s.substring_from(2).to_oct
			else if s1 == 'b' or s1 == 'B' then
				val = s.substring_from(2).to_bin
			else if s1.is_numeric then
				val = s.to_dec
			end
		else
			val = s.to_dec
		end
		return if neg then -val else val
	end