gistfile1.hs

module xtoa;

export xtoa;
export hexValue;
export decValue;
export binValue;

xtoa :: String, Int -> String;

hexValue :: Int -> String;
decValue :: Int -> String;
binValue :: Int -> String;

binValue(val) := xtoa("01", val);
decValue(val) := xtoa("0123456789", val);
hexValue(val) := xtoa("0123456789abcdef", val);

xtoa(alphabet, val) {
	base = length(alphabet);
	negative = false;
	case compare(val, 0) {
		@less {
			negative = true;
			val = -val;
		}
		@equal {
			return alphabet !! 0;
		}
		@greater {}
	}
	output = "";
	while val > 0 {
		output = [alphabet !! (val % base)] : output;
		val    = val / base;
	}
	if negative {
		output = "-" : output;
	}
	return output;
}