Why do I get the error “cannot borrow x as mutable more than once”?

Question

I\'m implementing a parser in Rust. I have to update the index for the lookahead, but when I call self.get() after self.current() I get an error:

Answer 1

@Adrian already gave the correct reason for why the compiler is giving the error message. If you bound the mutating expressions within a scope and then call self.get after the scope completion, you can compile the program.
The code can be modified as

loop{
    {
        let t = if let Some(token) = self.current(){
                    token
                }else{
                    break
                };
        println!("{:?}", t); 
    }
    let b = self.get();
    println!("{:?}", b);
}