#[derive(Debug, Eq, PartialEq, Clone)]
pub struct Token {
    start: usize,
    end: usize,
    kind: TokenKind,
}

impl Token {
    pub fn new(start: usize, end: usize, kind: TokenKind) -> Self {
        Self { start, end, kind }
    }

    pub fn start(&self) -> usize {
        self.start
    }

    pub fn end(&self) -> usize {
        self.end
    }

    pub fn kind(&self) -> TokenKind {
        self.kind
    }
}

#[derive(Debug, Clone, Copy, Eq, PartialEq)]
pub enum TokenKind {
    Fn,
    Identifier,
    LeftParentheses,
    RightParentheses,
    End,
    Let,
    Equals,
    IntegerLiteral,
    LongLiteral,
    String,
    Extern,
    Comma,
    Colon,
    RightArrow,
    Plus,
    Minus,
}