target_match/
error.rs

1//! Error type for `target-match`.
2//!
3//! Every fallible entry point returns [`Result`]. Errors arise only at the
4//! *construction* boundary — parsing coordinates, validating coordinate domains,
5//! and validating optics. Matching and precession are infallible once inputs are
6//! valid values (an [`crate::Equatorial`] always carries a fully-specified epoch,
7//! so there is no "epoch could not be resolved" runtime failure).
8
9use thiserror::Error;
10
11/// Everything that can go wrong constructing `target-match` values.
12#[derive(Debug, Clone, PartialEq, Error)]
13#[non_exhaustive]
14pub enum Error {
15    /// A coordinate string could not be parsed (empty, non-numeric, malformed
16    /// sexagesimal, or negative minutes/seconds).
17    #[error("could not parse coordinate: {0}")]
18    ParseCoord(String),
19
20    /// A numeric coordinate or epoch was outside its valid domain
21    /// (RA `[0, 360)`, Dec `[-90, 90]`, or a non-finite epoch year).
22    #[error("{what} out of range: {value}")]
23    OutOfRange {
24        /// Which quantity was out of range (e.g. `"right ascension"`).
25        what: &'static str,
26        /// The offending value.
27        value: f64,
28    },
29
30    /// Optics or field inputs were non-positive, non-finite, or insufficient to
31    /// derive a field of view.
32    #[error("invalid optics: {0}")]
33    InvalidOptics(String),
34}
35
36/// Convenience alias for `Result<T, `[`Error`](enum@Error)`>`.
37pub type Result<T> = core::result::Result<T, Error>;
38
39#[cfg(test)]
40mod tests {
41    use super::*;
42
43    #[test]
44    fn display_messages() {
45        assert_eq!(
46            Error::ParseCoord("x".into()).to_string(),
47            "could not parse coordinate: x"
48        );
49        assert_eq!(
50            Error::OutOfRange {
51                what: "declination",
52                value: 91.0
53            }
54            .to_string(),
55            "declination out of range: 91"
56        );
57        assert_eq!(
58            Error::InvalidOptics("focal <= 0".into()).to_string(),
59            "invalid optics: focal <= 0"
60        );
61    }
62}
target_match/error.rs

target_match/
error.rs
