/// Returns the next token in the stream without consuming it.
Returns the next token in the stream without consuming it.
Returns the next token in the stream without consuming it .
pub fn peek(&mut self) -> Option<Result<Token>> {
        match self.next() {
            Some(Ok(tok)) => {
                self.put_back(tok.clone());
                Some(Ok(tok))
            }
            Some(Err(e)) => Some(Err(e)),
            None => None,
        }
    }
pub fn peek ( & mut self ) -> Option < Result < Token > > { match self . next ( ) { Some ( Ok ( tok ) ) => { self . put_back ( tok . clone ( ) ) ; Some ( Ok ( tok ) ) } Some ( Err ( e ) ) => Some ( Err ( e ) ) , None => None , } }
Returns the next token in the stream without consuming it.
Returns the next token in the stream without consuming it .
&mut self