src/error.rs

use serde::de::Error as DeError;
use serde::ser::Error as SerError;
use std::fmt::Display;
use thiserror::Error;

#[derive(Debug, Error)]
pub enum Error {
    #[error("Expected token {token}, found {found}")]
    UnexpectedToken { token: String, found: String },
    #[error("custom: {field}")]
    Custom { field: String },
    #[error("unsupported operation: '{operation}'")]
    UnsupportedOperation { operation: String },

    #[error("IO error: {source}")]
    Io {
        #[from]
        source: ::std::io::Error,
    },

    #[error("FromUtf8Error: {source}")]
    FromUtf8Error {
        #[from]
        source: ::std::string::FromUtf8Error,
    },

    #[error("ParseIntError: {source}")]
    ParseIntError {
        #[from]
        source: ::std::num::ParseIntError,
    },

    #[error("ParseFloatError: {source}")]
    ParseFloatError {
        #[from]
        source: ::std::num::ParseFloatError,
    },

    #[error("ParseBoolError: {source}")]
    ParseBoolError {
        #[from]
        source: ::std::str::ParseBoolError,
    },

    #[error("Syntax: {source}")]
    Syntax {
        #[from]
        source: ::xml::reader::Error,
    },

    #[error("Writer: {source}")]
    Writer {
        #[from]
        source: ::xml::writer::Error,
    },
}

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

#[macro_export]
macro_rules! expect {
    ($actual: expr, $($expected: pat)|+ => $if_ok: expr) => {
        match $actual {
            $($expected)|+ => $if_ok,
            actual => Err($crate::Error::UnexpectedToken {
                token: stringify!($($expected)|+).to_string(),
                found: format!("{:?}",actual)
            }) as Result<_>
        }
    }
}

#[cfg(debug_assertions)]
#[macro_export]
macro_rules! debug_expect {
    ($actual: expr, $($expected: pat)|+ => $if_ok: expr) => {
        match $actual {
            $($expected)|+ => $if_ok,
            actual => panic!(
                "Internal error: Expected token {}, found {:?}",
                stringify!($($expected)|+),
                actual
            )
        }
    }
}

#[cfg(not(debug_assertions))]
#[macro_export]
macro_rules! debug_expect {
    ($actual: expr, $($expected: pat)|+ => $if_ok: expr) => {
        match $actual {
            $($expected)|+ => $if_ok,
            _ => unreachable!()
        }
    }
}

impl DeError for Error {
    fn custom<T: Display>(msg: T) -> Self {
        Error::Custom {
            field: msg.to_string(),
        }
    }
}

impl SerError for Error {
    fn custom<T: Display>(msg: T) -> Self {
        Error::Custom {
            field: msg.to_string(),
        }
    }
}