Macro unexpected_token 

macro_rules! unexpected_token {
    ($span:expr, $expected:expr, $found:expr) => { ... };
}

Macro to create an UnexpectedToken error with expected and found values.

Usage

unexpected_token!(span, ["expected1", "expected2"], "found_value")
unexpected_token!(span, vec!["expected1".to_string()], format!("{:?}", token))