//! This module contains the error types for the tokeniser.

#[derive(Debug, Clone, Copy)]
/// Types of errors that may be returned during tokenisation.
pub enum TokeniserError {
    /// An unexpected character was found in the source code.
    UnexpectedChar(char),
    /// An unterminated string literal was found. [`SourceInfo`] will be attached if this
    /// was returned.
    UnterminatedString,
    /// An invalid number format was encountered when parsing a literal value
    /// ([`TokenType::Immediate`]).
    InvalidNumber(&'static str),
    /// An unrecognized token was encountered.
    UnrecognisedToken,
}

impl TokeniserError {}

impl std::fmt::Display for TokeniserError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::UnexpectedChar(c) => write!(f, "unexpected char '{c}' found in input")?,
            Self::InvalidNumber(lit) => {
                write!(f, "invalid integer literal \"{lit}\" found in input")?;
            }
            &Self::UnrecognisedToken => write!(f, "unrecognised token found in input")?,
            &Self::UnterminatedString => write!(f, "unterminated string literal")?,
        }

        Ok(())
    }
}