mdict-rs 0.1.4

Library-first Rust parser for MDict .mdx and .mdd dictionaries
Documentation
use std::fmt;

pub type Result<T, E = Error> = std::result::Result<T, E>;

#[derive(Debug)]
pub enum Error {
    Io(std::io::Error),
    InvalidFormat(&'static str),
    InvalidData(String),
    Truncated {
        context: &'static str,
        needed: usize,
        remaining: usize,
    },
    LimitExceeded {
        limit: &'static str,
        value: u64,
        max: u64,
    },
    ChecksumMismatch {
        context: &'static str,
        expected: u32,
        actual: u32,
    },
    Decode {
        context: &'static str,
        encoding: &'static str,
    },
    MissingPasscode,
    Unsupported(&'static str),
}

impl Error {
    pub fn truncated(context: &'static str, needed: usize, remaining: usize) -> Self {
        Self::Truncated {
            context,
            needed,
            remaining,
        }
    }
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::Io(error) => write!(f, "I/O error: {error}"),
            Self::InvalidFormat(context) => write!(f, "invalid format: {context}"),
            Self::InvalidData(context) => write!(f, "invalid data: {context}"),
            Self::Truncated {
                context,
                needed,
                remaining,
            } => write!(
                f,
                "truncated {context}: need {needed} bytes, have {remaining}"
            ),
            Self::LimitExceeded { limit, value, max } => {
                write!(f, "limit exceeded for {limit}: {value} > {max}")
            }
            Self::ChecksumMismatch {
                context,
                expected,
                actual,
            } => write!(
                f,
                "checksum mismatch for {context}: expected {expected:#010x}, got {actual:#010x}"
            ),
            Self::Decode { context, encoding } => {
                write!(f, "failed to decode {context} using {encoding}")
            }
            Self::MissingPasscode => write!(f, "dictionary requires a passcode"),
            Self::Unsupported(feature) => write!(f, "unsupported feature: {feature}"),
        }
    }
}

impl std::error::Error for Error {
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        match self {
            Self::Io(error) => Some(error),
            _ => None,
        }
    }
}

impl From<std::io::Error> for Error {
    fn from(value: std::io::Error) -> Self {
        Self::Io(value)
    }
}