matten_ndarray/
error.rs

1//! Error type for `matten-ndarray` (RFC-025 §7, RFC-027 §5).
2//!
3//! The bridge defines its own error type rather than growing core
4//! [`matten::MattenError`] (RFC-022 §8). Conversions return `Result`; a dynamic
5//! tensor returns [`MattenNdarrayError::DynamicTensor`] rather than panicking.
6
7use std::fmt;
8
9/// Errors produced by the `matten` ↔ `ndarray` conversions.
10///
11/// `#[non_exhaustive]` so future variants are not a breaking change.
12#[derive(Debug)]
13#[non_exhaustive]
14pub enum MattenNdarrayError {
15    /// A dynamic (`Element`) tensor was passed to a conversion. Convert it to a
16    /// numeric tensor first with `Tensor::try_numeric()`.
17    DynamicTensor,
18    /// Formerly returned when the input `ndarray` shape contained a
19    /// zero-length axis. Core `matten` now accepts zero-sized dimensions
20    /// (RFC-111), so `from_arrayd` no longer rejects one — this variant is
21    /// never constructed. Kept, rather than removed, because the enum is
22    /// `#[non_exhaustive]` but a *removed* variant still breaks anyone
23    /// matching on it.
24    #[deprecated(
25        note = "from_arrayd accepts a zero-length axis since RFC-111; this variant is never constructed"
26    )]
27    ZeroSizedAxis(Vec<usize>),
28    /// `ndarray` could not construct the target array (e.g. a shape/length
29    /// mismatch).
30    NdarrayShape(ndarray::ShapeError),
31    /// Core `matten` rejected the conversion (e.g. the rank exceeds `MAX_NDIM`).
32    Matten(matten::MattenError),
33}
34
35impl fmt::Display for MattenNdarrayError {
36    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
37        match self {
38            MattenNdarrayError::DynamicTensor => write!(
39                f,
40                "matten-ndarray error: dynamic tensors cannot be converted; call \
41                 try_numeric() to convert to a numeric tensor first"
42            ),
43            #[allow(deprecated)]
44            MattenNdarrayError::ZeroSizedAxis(shape) => write!(
45                f,
46                "matten-ndarray error: ndarray shape {shape:?} contains a zero-length \
47                 axis (unreachable: from_arrayd has accepted these since RFC-111)"
48            ),
49            MattenNdarrayError::NdarrayShape(e) => {
50                write!(
51                    f,
52                    "matten-ndarray error: ndarray could not build the array: {e}"
53                )
54            }
55            MattenNdarrayError::Matten(e) => {
56                write!(
57                    f,
58                    "matten-ndarray error: matten rejected the conversion: {e}"
59                )
60            }
61        }
62    }
63}
64
65impl std::error::Error for MattenNdarrayError {
66    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
67        match self {
68            MattenNdarrayError::NdarrayShape(e) => Some(e),
69            MattenNdarrayError::Matten(e) => Some(e),
70            _ => None,
71        }
72    }
73}
matten_ndarray/error.rs

matten_ndarray/
error.rs
