// Converts number[unit] string into value
// -------------------------------------------------------------------------------
// @documentation http://hugogiraudel.com/2014/01/15/sass-string-to-number/
// -------------------------------------------------------------------------------
// @param $number [string] : number
// @param $unit [string] : unit
// -------------------------------------------------------------------------------
// @return [integer]

@function num-length($number, $unit) {
	$strings: 'px' 'cm' 'mm' '%' 'ch' 'pica' 'in' 'em' 'rem' 'pt' 'pc' 'ex' 'vw' 'vh' 'vmin' 'vmax';
	$units:   1px  1cm  1mm  1%  1ch  1pica  1in  1em  1rem  1pt  1pc  1ex  1vw  1vh  1vmin  1vmax;
	$index: index($strings, $unit);

	@if not $index {
		@warn "Unknown unit `#{$unit}`.";
		@return false;
	}

	@return $number * nth($units, $index);
}

// Converts number to string
// -------------------------------------------------------------------------------
// @documentation http://hugogiraudel.com/2014/01/15/sass-string-to-number/
// -------------------------------------------------------------------------------
// @dependence `num-length()`
// -------------------------------------------------------------------------------
// @param $string [String] : string
// -------------------------------------------------------------------------------
// @return [Value]

@function to-number($string) {
	// Matrices
	$strings: '0' '1' '2' '3' '4' '5' '6' '7' '8' '9';
	$numbers:  0   1   2   3   4   5   6   7   8   9;

	// Result
	$result: 0;
	$divider: 0;
	$minus: false;

	// Looping through all characters
	@for $i from 1 through str-length($string) {
		$character: str-slice($string, $i, $i);
		$index: index($strings, $character);

		@if $character == '-' {
			$minus: true;
		} @else if $character == '.' {
			$divider: 1;
		} @else {

			@if not $index {
				$result: if($minus, $result * -1, $result);
				@return num-length($result, str-slice($string, $i));
			}

			$number: nth($numbers, $index);

			@if $divider == 0 {
				$result: $result * 10;
			} @else {
				// Move the decimal dot to the left
				$divider: $divider * 10;
				$number: $number / $divider;
			}
			$result: $result + $number;
		}
	}
	
	@return if($minus, $result * -1, $result);
}