shellfn_core/
error.rs

1use std::error::Error as StdError;
2use std::io;
3use std::process::Output;
4use std::string::FromUtf8Error;
5
6#[derive(Debug)]
7pub enum Error<PE: StdError> {
8    NonUtf8Stdout(FromUtf8Error),
9    ParsingError(PE),
10    ProcessNotSpawned(io::Error),
11    StdoutUnreadable(io::Error),
12    WaitFailed(io::Error),
13    ProcessFailed(Output),
14}
15
16// TODO: replace with `!` after stabilization
17#[derive(Debug, Copy, Clone, Eq, PartialEq)]
18pub enum NeverError {}
19
20impl<PE: StdError> StdError for Error<PE> {
21    fn description(&self) -> &str {
22        match self {
23            Error::NonUtf8Stdout(_)     => "subprocess stdout contains non-utf8 characters",
24            Error::ParsingError(_)      => "could not parse subprocess output",
25            Error::ProcessNotSpawned(_) => "could not spawn subprocess",
26            Error::StdoutUnreadable(_)  => "could not read subprocess stdout",
27            Error::WaitFailed(_)        => "subprocess failed",
28            Error::ProcessFailed(_)     => "subprocess finished with error",
29        }
30    }
31
32    fn cause(&self) -> Option<&StdError> {
33        match self {
34            Error::NonUtf8Stdout(ref e)     => Some(e),
35            Error::ParsingError(ref e)      => Some(e),
36            Error::ProcessNotSpawned(ref e) => Some(e),
37            Error::StdoutUnreadable(ref e)  => Some(e),
38            Error::WaitFailed(ref e)        => Some(e),
39            Error::ProcessFailed(_)         => None,
40        }
41    }
42}
43
44impl<PE: StdError> std::fmt::Display for Error<PE> {
45    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
46        write!(f, "{}", self.description())
47    }
48}
49
50impl StdError for NeverError {
51    fn description(&self) -> &str {
52        ""
53    }
54
55    fn cause(&self) -> Option<&StdError> {
56        None
57    }
58}
59
60impl std::fmt::Display for NeverError {
61    fn fmt(&self, _f: &mut std::fmt::Formatter) -> std::fmt::Result {
62        Ok(())
63    }
64}
shellfn_core/error.rs

shellfn_core/
error.rs
