fn skip_whitespace(&mut self) {
        while self.current_char.is_ascii_whitespace() && self.current_char != b'\n' {
            self.advance()
        }
    }
/// set parser to next non-whitespace character except newlines
set parser to next non-whitespace character except newlines
set parser to next non - whitespace character except newlines
fn skip_whitespace(&mut self) {
        while self.current_char.is_ascii_whitespace() && self.current_char != b'\n' {
            self.advance()
        }
    }
fn skip_whitespace ( & mut self ) { while self . current_char . is_ascii_whitespace ( ) && self . current_char != b'\n' { self . advance ( ) } }
set parser to next non-whitespace character except newlines
set parser to next non - whitespace character except newlines
&mut self
&mut self