// Utility functions that don't depend on the Lexer state.
Utility functions that don't depend on the Lexer state.
Utility functions that don ' t depend on the Lexer state .
fn from_digit(ch: char) -> Option<u32> {
        if '0' <= ch && ch <= '9' {
            return Some( (ch as u32) - ('0' as u32) )
        }
        else if 'a' <= ch && ch <= 'f' {
            return Some( (ch as u32) - ('a' as u32) + 10 )
        }
        else if 'A' <= ch && ch <= 'F' {
            return Some( (ch as u32) - ('A' as u32) + 10 )
        }
        None
    }
fn from_digit ( ch : char ) -> Option < u32 > { if '0' <= ch && ch <= '9' { return Some ( ( ch as u32 ) - ( '0' as u32 ) ) } else if 'a' <= ch && ch <= 'f' { return Some ( ( ch as u32 ) - ( 'a' as u32 ) + 10 ) } else if 'A' <= ch && ch <= 'F' { return Some ( ( ch as u32 ) - ( 'A' as u32 ) + 10 ) } None }
Utility functions that don't depend on the Lexer state.
Utility functions that don ' t depend on the Lexer state .
ch
char