Macro stringsext::parse_filter_parameter

macro_rules! parse_filter_parameter {
    ($s : expr, $x_from_str_radix : expr, $list : expr) => { ... };
}

Parses a filter expression from some hexadecimal string or from some filter-alias-name in $list to a filter-integer value.

$s is Option<String> to be parsed. $list is either ASCII_FILTER_ALIASSE or UNICODE_BLOCK_FILTER_ALIASSE. $x_from_str_radix is either u128::from_str_radix or u64::from_str_radix`.

The marco returns a filter integer value in Option<integer> and returns early when parsing is not successful.