1 | use std::error; |
2 | use std::fmt; |
3 | use std::io; |
4 | use std::path::{Path, PathBuf}; |
5 | |
6 | /// Represents any kind of error that can occur while parsing the UCD. |
7 | #[derive (Debug)] |
8 | pub struct Error { |
9 | pub(crate) kind: ErrorKind, |
10 | pub(crate) line: Option<u64>, |
11 | pub(crate) path: Option<PathBuf>, |
12 | } |
13 | |
14 | /// The kind of error that occurred while parsing the UCD. |
15 | #[derive (Debug)] |
16 | pub enum ErrorKind { |
17 | /// An I/O error. |
18 | Io(io::Error), |
19 | /// A generic parse error. |
20 | Parse(String), |
21 | } |
22 | |
23 | impl Error { |
24 | /// Create a new parse error from the given message. |
25 | pub(crate) fn parse(msg: String) -> Error { |
26 | Error { kind: ErrorKind::Parse(msg), line: None, path: None } |
27 | } |
28 | |
29 | /// Return the specific kind of this error. |
30 | pub fn kind(&self) -> &ErrorKind { |
31 | &self.kind |
32 | } |
33 | |
34 | /// Return the line number at which this error occurred, if available. |
35 | pub fn line(&self) -> Option<u64> { |
36 | self.line |
37 | } |
38 | |
39 | /// Return the file path associated with this error, if one exists. |
40 | pub fn path(&self) -> Option<&Path> { |
41 | self.path.as_ref().map(|p| &**p) |
42 | } |
43 | |
44 | /// Unwrap this error into its underlying kind. |
45 | pub fn into_kind(self) -> ErrorKind { |
46 | self.kind |
47 | } |
48 | |
49 | /// Returns true if and only if this is an I/O error. |
50 | /// |
51 | /// If this returns true, the underlying `ErrorKind` is guaranteed to be |
52 | /// `ErrorKind::Io`. |
53 | pub fn is_io_error(&self) -> bool { |
54 | match self.kind { |
55 | ErrorKind::Io(_) => true, |
56 | _ => false, |
57 | } |
58 | } |
59 | } |
60 | |
61 | impl error::Error for Error { |
62 | fn cause(&self) -> Option<&dyn error::Error> { |
63 | match self.kind { |
64 | ErrorKind::Io(ref err: &Error) => Some(err), |
65 | _ => None, |
66 | } |
67 | } |
68 | } |
69 | |
70 | impl fmt::Display for Error { |
71 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
72 | if let Some(ref path: &PathBuf) = self.path { |
73 | if let Some(line: u64) = self.line { |
74 | write!(f, " {}: {}: " , path.display(), line)?; |
75 | } else { |
76 | write!(f, " {}: " , path.display())?; |
77 | } |
78 | } else if let Some(line: u64) = self.line { |
79 | write!(f, "error on line {}: " , line)?; |
80 | } |
81 | match self.kind { |
82 | ErrorKind::Io(ref err: &Error) => write!(f, " {}" , err), |
83 | ErrorKind::Parse(ref msg: &String) => write!(f, " {}" , msg), |
84 | } |
85 | } |
86 | } |
87 | |