function namespace (element) {
	switch (element.type) {
		case RULESET:
			element.props = element.props.map(function (value) {
				return combine(tokenize(value), function (value, index, children) {
					switch (charat(value, 0)) {
						// \f
						case 12:
							return substr(value, 1, strlen(value))
						// \0 ( + > ~
						case 0: case 40: case 43: case 62: case 126:
							return value
						// :
						case 58:
							if (children[++index] === 'global')
								children[index] = '', children[++index] = '\f' + substr(children[index], index = 1, -1)
						// \s
						case 32:
							return index === 1 ? '' : value
						default:
							switch (index) {
								case 0: element = value
									return sizeof(children) > 1 ? '' : value
								case index = sizeof(children) - 1: case 2:
									return index === 2 ? value + element + element : value + element
								default:
									return value
							}
					}
				})
			})
	}
}
@param {object} element
@param {number} index
@param {object[]} children