xref: /third_party/rust/crates/cxx/gen/lib/src/error.rs (revision 33d722a9) 
1// We can expose more detail on the error as the need arises, but start with an
2// opaque error type for now.
3
4use std::error::Error as StdError;
5use std::fmt::{self, Debug, Display};
6use std::iter;
7
8#[allow(missing_docs)]
9pub struct Error {
10    pub(crate) err: crate::gen::Error,
11}
12
13impl Error {
14    /// Returns the span of the error, if available.
15    pub fn span(&self) -> Option<proc_macro2::Span> {
16        match &self.err {
17            crate::gen::Error::Syn(err) => Some(err.span()),
18            _ => None,
19        }
20    }
21}
22
23impl From<crate::gen::Error> for Error {
24    fn from(err: crate::gen::Error) -> Self {
25        Error { err }
26    }
27}
28
29impl Display for Error {
30    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
31        Display::fmt(&self.err, f)
32    }
33}
34
35impl Debug for Error {
36    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
37        Debug::fmt(&self.err, f)
38    }
39}
40
41impl StdError for Error {
42    fn source(&self) -> Option<&(dyn StdError + 'static)> {
43        self.err.source()
44    }
45}
46
47impl IntoIterator for Error {
48    type Item = Error;
49    type IntoIter = IntoIter;
50
51    fn into_iter(self) -> Self::IntoIter {
52        match self.err {
53            crate::gen::Error::Syn(err) => IntoIter::Syn(err.into_iter()),
54            _ => IntoIter::Other(iter::once(self)),
55        }
56    }
57}
58
59pub enum IntoIter {
60    Syn(<syn::Error as IntoIterator>::IntoIter),
61    Other(iter::Once<Error>),
62}
63
64impl Iterator for IntoIter {
65    type Item = Error;
66
67    fn next(&mut self) -> Option<Self::Item> {
68        match self {
69            IntoIter::Syn(iter) => iter
70                .next()
71                .map(|syn_err| Error::from(crate::gen::Error::Syn(syn_err))),
72            IntoIter::Other(iter) => iter.next(),
73        }
74    }
75}
76