_lower_map = {
	A: 'a',
	B: 'b',
	C: 'c',
	D: 'd',
	E: 'e',
	F: 'f',
	G: 'g',
	H: 'h',
	I: 'i',
	J: 'j',
	K: 'k',
	L: 'l',
	M: 'm',
	N: 'n',
	O: 'o',
	P: 'p',
	Q: 'q',
	R: 'r',
	S: 's',
	T: 't',
	U: 'u',
	V: 'v',
	W: 'w',
	X: 'x',
	Y: 'y',
	Z: 'z'
}

lower(string)
	for upper, lower in _lower_map
		string = replace(upper, lower, string)
	string
	
upper(string)
	for upper, lower in _lower_map
		string = replace(lower, upper, string)
	string

RV-CSSParameter(block)
	for name, value in block
		css-var-name = '--%s' % unquote(name)
		add-property(css-var-name, value)
		define('--'+name, unquote('var(--%s)' % (unquote(name))), true)