fn from_char(c: char) -> u8 {
    match c {
        'A'..='Z' => c as u8 - b'A',
        'a'..='z' => c as u8 - b'a',
        '0'..='9' => c as u8 - b'0' + 26,
        _ => panic!("invalid char"), // TODO
    }
}
// from_char maps the encoded code-points to their digit values.
// The returned value is in the range 0 to BASE.
from_char maps the encoded code-points to their digit values.
The returned value is in the range 0 to BASE.
from_char maps the encoded code - points to their digit values . The returned value is in the range 0 to BASE .
fn from_char(c: char) -> u8 {
    match c {
        'A'..='Z' => c as u8 - b'A',
        'a'..='z' => c as u8 - b'a',
        '0'..='9' => c as u8 - b'0' + 26,
        _ => panic!("invalid char"), // TODO
    }
}
fn from_char ( c : char ) -> u8 { match c { 'A' ..= 'Z' => c as u8 - b'A' , 'a' ..= 'z' => c as u8 - b'a' , '0' ..= '9' => c as u8 - b'0' + 26 , _ => panic ! ( " " ) , // TODO } }
from_char maps the encoded code-points to their digit values.
from_char maps the encoded code - points to their digit values .
c
char