String.prototype.toUTF8Array = function(){
	var arr = [];

	for(var i = 0; i < this.length; ++i){
		var c = this.charCodeAt(i);

		/* Convert from UTF-16 to Unicode code point. */
		if((c & 0xDC00) == 0xD800){
			var lead = c;
			var tail = this.charCodeAt(++i);

			c = 0x10000 | ((lead & 0x3FF) << 10) | ((tail & 0x3FF));
		}

		/* Convert from code point to UTF-8. */
		if(c > 0x10000){ /* 4 bytes */
			arr.push(0xF0 | ((c & 0x1C0000) >> 18));
			arr.push(0x80 | ((c & 0x3F000) >> 12));
			arr.push(0x80 | ((c & 0xFC0) >> 6));
			arr.push(0x80 | ((c & 0x3F)));
		}else if(c > 0x0800){ /* 3 bytes */
			arr.push(0xE0 | ((c & 0xF000) >> 12));
			arr.push(0x80 | ((c & 0xFC0) >> 6));
			arr.push(0x80 | ((c & 0x3F)));
		}else if(c > 0x0080){ /* 2 bytes */
			arr.push(0xC0 | ((c & 0xFC0) >> 6));
			arr.push(0x80 | ((c & 0x3F)));
		}else{ /* 1 byte */
			arr.push(0x00 | ((c & 0x7F)));
		}
	}

	return arr;
}

String.fromUTF8Array = function(arr){
	var units = [];

	for(var i = 0; i < arr.length; ++i){
		var codepoint = 0;

		/* Convert from UTF-8 to Unicode codepoint. */
		if((arr[i] & 0x80) == 0){ /* one byte */
			codepoint = arr[i] & 0x7F;
		}else if((arr[i] & 0xE0) == 0xC0){ /* two bytes */
			codepoint = (
				((arr[i] & 0x1F) << 6) |
				((arr[++i] & 0x3F))
			);
		}else if((arr[i] & 0xF0) == 0xE0){ /* three bytes */
			codepoint = (
				((arr[i] & 0x0F) << 12) |
				((arr[++i] & 0x3F) << 6) |
				((arr[++i] & 0x3F))
			);
		}else if((arr[i] & 0xF8) == 0xF0){ /* four bytes */
			codepoint = (
				((arr[i] & 0x07) << 18) |
				((arr[++i] & 0x3F) << 12) |
				((arr[++i] & 0x3F) << 6) |
				((arr[++i] & 0x3F))
			);
		}else{
			/* five- and six- byte UTF-8 are now illegal. */
		}

		/* Convert from Unicode codepoint to UTF-16. */
		if(codepoint & 0x10000){
			units.push(0xD800 | ((codepoint >> 10) & 0x3FF));
			units.push(0xDC00 | (codepoint & 0x3FF));
		}else{
			units.push(codepoint);
		}
	}
	return String.fromCharCode.apply(null, units);
}