use derive_enum_error::Error;
use std::error::Error;
use std::path::PathBuf;
#[derive(Debug, Error)]
pub enum FormatError {
#[error(
display = "invalid header (expected: {:?}, got: {:?})",
expected,
found
)]
InvalidHeader { expected: String, found: String },
#[error(display = "missing attribute: {:?}", _0)]
MissingAttribute(String),
}
#[derive(Debug, Error)]
pub enum LoadingError {
#[error(display = "could not decode file")]
FormatError(#[error(source)] FormatError),
#[error(display = "could not find file: {:?}", path)]
NotFound { path: PathBuf },
}
impl From<FormatError> for LoadingError {
fn from(f: FormatError) -> Self {
LoadingError::FormatError(f)
}
}
fn main() {
let my_error: LoadingError = FormatError::MissingAttribute("some_attr".to_owned()).into();
print_error(&my_error);
}
fn print_error(e: &dyn Error) {
eprintln!("error: {}", e);
let mut source = e.source();
while let Some(e) = source {
eprintln!("sourced by: {}", e);
source = e.source();
}
}