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use std::error::Error as StdError;
use std::fmt;
use crate::compile::CompileError;
use crate::encode::{DecodeError, EncodeError};
use crate::exec::ExecError;
use crate::io::IoError;
use crate::name::{NameDisplay, NameStore};
use crate::parser::ParseError;
use crate::restrict::RestrictError;
macro_rules! error_type {
( $( #[$meta:meta] )* pub enum $name:ident
{ $( $( #[$var_meta:meta] )+ $var:ident($ty:ty) , )+ } ) => {
$( #[$meta] )*
pub enum $name {
$( $( #[$var_meta] )+ $var($ty) ),+
}
impl fmt::Display for $name {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
$( $name::$var(ref e) => fmt::Display::fmt(e, f) ),+
}
}
}
impl NameDisplay for $name {
fn fmt(&self, names: &NameStore, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
$( $name::$var(ref e) => NameDisplay::fmt(e, names, f) ),+
}
}
}
$(
impl From<$ty> for $name {
fn from(e: $ty) -> $name {
$name::$var(e)
}
}
)+
}
}
error_type!{
#[derive(Debug)]
pub enum Error {
CompileError(CompileError),
DecodeError(DecodeError),
EncodeError(EncodeError),
ExecError(ExecError),
IoError(IoError),
ParseError(ParseError),
RestrictError(RestrictError),
Custom(Box<dyn StdError>),
}
}
impl Error {
pub fn custom<E: 'static + StdError>(e: E) -> Error {
Error::Custom(Box::new(e))
}
pub fn description(&self) -> &'static str {
match *self {
Error::CompileError(_) => "compile error",
Error::DecodeError(_) => "decode error",
Error::EncodeError(_) => "encode error",
Error::ExecError(_) => "execution error",
Error::IoError(_) => "I/O error",
Error::ParseError(_) => "parse error",
Error::RestrictError(_) => "restriction error",
Error::Custom(_) => "error",
}
}
}
impl StdError for Error {
fn description(&self) -> &str {
self.description()
}
}
#[cfg(test)]
mod test {
use std::error::Error as StdError;
use std::fmt;
use super::Error;
#[derive(Debug)]
struct E;
impl fmt::Display for E {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str("an error occurred")
}
}
impl StdError for E {
fn description(&self) -> &str { "error" }
}
#[test]
fn test_custom_error() {
let e = Error::custom(E);
assert_eq!(e.description(), "error");
assert_eq!(e.to_string(), "an error occurred");
}
}