opacify($color, $amount) Also known as: fade_in Makes

opacity($color) Returns the alpha component (opacity) of a color. This is 1 unless otherwise specified.

simple_selectors($selector) Returns the simple

str_slice($string, $start-at, $end-at:-1) Extracts a substring from $string. The substring will begin at index

function_exists($name) Check whether a function with the given name exists.

length($list) Return the length of a list. This can return the number of pairs in a map as

ie_hex_str($color) Converts a color into the format understood by IE filters.

floor($number) Rounds a number down to the previous whole number.

abs($number) Returns the absolute value of a number.

hsl($hue, $saturation, $lightness) Creates a Color from hue, saturation, and lightness values