use std::fmt::{Debug, Display, Formatter, Error};

use crate::tokens::MpsToken;
use super::MpsOp;

#[derive(Debug)]
pub struct SyntaxError {
    pub line: usize,
    pub token: MpsToken,
}

impl Display for SyntaxError {
    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
        write!(f, "SyntaxError (line {}): Unexpected {}", &self.line, &self.token)
    }
}

impl MpsLanguageError for SyntaxError {
    fn set_line(&mut self, line: usize) {self.line = line}
}

#[derive(Debug)]
pub struct RuntimeError {
    pub line: usize,
    pub op: Box<dyn MpsOp>,
    pub msg: String,
}

impl Display for RuntimeError {
    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
        write!(f, "{} (line {}): {}", &self.msg, &self.line, &self.op)
    }
}

impl MpsLanguageError for RuntimeError {
    fn set_line(&mut self, line: usize) {self.line = line}
}

pub trait MpsLanguageError: Display + Debug {
    fn set_line(&mut self, line: usize);
}