peek method

String peek([ int count = 1 ])

Get a substring from the document. If count is negative, this function returns count.abs() characters leading up to the current position. If count is positive, this function returns count characters after the current position. If count is 0, this function returns an empty string. The calculated start and end positions of peek are bounds-checked (meaning they bottom out at 0 and top out at length.)

Implementation

String peek([int count = 1]) {
		int start, end;
		switch (count) {
			// easy cases that don't require substring
			case 1:
				// return next character
				return document[clampPos(position)];
			case -1:
				// return previous character
				return document[clampPos(position - 1)];
			// everything else
			default:
				// calculate start/stop pos
				start = clampPos(position + (count < 0 ? count : 0));
				end = clampPos(position + (count > 0 ? count : 0));
				// return substring
    		return document.substring(start, end);
		}
}