pub fn parse_subscript_digits(s: &str) -> Option<u64>Expand description
Reads a number written as a run of Unicode subscript digits.
This accepts exactly what fmt_subscript_digits writes, and nothing else: the empty string, a
string holding anything but a subscript digit, a string with a leading zero, and a number too
large for a u64 are all rejected. Accepting only the one spelling of a number is what makes
the two functions inverse to each other.
§Worst-case complexity
$T(n) = O(n)$
$M(n) = O(1)$
where $T$ is time, $M$ is additional memory, and $n$ is s.len().
§Examples
use malachite_base::chars::scripts::parse_subscript_digits;
assert_eq!(parse_subscript_digits("₀"), Some(0));
assert_eq!(parse_subscript_digits("₁₀"), Some(10));
assert_eq!(parse_subscript_digits(""), None);
assert_eq!(parse_subscript_digits("10"), None);
assert_eq!(parse_subscript_digits("₀₁"), None);