mime_tree/
error.rs

1use std::fmt;
2
3/// Error returned when `parse()` cannot produce any result from the input bytes.
4///
5/// Best-effort parsing: malformed-but-parseable input yields a `ParsedMessage`
6/// with `warnings` populated. Only truly unrecoverable input returns `Err`.
7#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
8#[non_exhaustive]
9pub enum ParseError {
10    /// The input byte slice is empty.
11    EmptyInput,
12    /// The input contains no recognizable RFC 5322 headers.
13    NoHeaders,
14    /// The byte range specified in a `ParsedPart` extends beyond the raw message bytes.
15    ///
16    /// `offset` and `length` are `u32` to match `ParsedPart::body_range`.
17    /// `available` is `u64` because it comes from `raw.len() as u64` —
18    /// using `u64` avoids a lossy truncation on platforms where `usize > u32`
19    /// and makes the error message unambiguous even if the slice length
20    /// exceeds 4 GiB (which `ParsedPart` cannot address, but the caller's
21    /// buffer might be that large).
22    InvalidRange {
23        offset: u32,
24        length: u32,
25        available: u64,
26    },
27}
28
29impl fmt::Display for ParseError {
30    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
31        match self {
32            ParseError::EmptyInput => write!(f, "input is empty"),
33            ParseError::NoHeaders => write!(f, "input contains no RFC 5322 headers"),
34            ParseError::InvalidRange {
35                offset,
36                length,
37                available,
38            } => write!(
39                f,
40                "body range [{}..{}] extends beyond message length {}",
41                offset,
42                u64::from(*offset) + u64::from(*length),
43                available,
44            ),
45        }
46    }
47}
48
49impl std::error::Error for ParseError {}
mime_tree/error.rs

mime_tree/
error.rs
