Example - Rust Pattern Matching

pattern.rs

let v: Vec<&Token> = tokens.iter().enumerate().filter_map(|(i, token)| {
        match token.t {
            t if t == TokenType::Function && tokens[i + 1].t == TokenType::Name => Some(token),
            t if t == TokenType::Name && tokens[i + 1].t == TokenType::Lp => Some(token),
            TokenType::Function
            | TokenType::Add
            | TokenType::Eos
            | TokenType::End
            | TokenType::Name
            | TokenType::Comma
            | TokenType::Rp => Some(token),
            _ => None,
        }
    }).collect();