lattice_core/
error.rs

1//! The crate's error type, [`CoreError`], and its [`CoreResult`] alias.
2
3use thiserror::Error;
4
5use lattice_protocol::ProtocolError;
6
7/// Every error `lattice-core` returns.
8///
9/// Callers mostly propagate it with `?` via [`CoreResult`]. The variants
10/// worth matching on are [`CoreError::NothingToUndo`] /
11/// [`CoreError::NothingToRedo`] (a user-facing no-op, not a failure) and
12/// [`CoreError::Cancelled`] (a cooperative abort, not a failure either).
13#[derive(Debug, Error)]
14pub enum CoreError {
15    /// A position or range was invalid for the buffer it was applied to
16    /// (out of bounds, or `end < start`). Raised by
17    /// [`Buffer::slice`](crate::Buffer::slice),
18    /// [`Buffer::apply_edit`](crate::Buffer::apply_edit) and everything built
19    /// on them.
20    #[error(transparent)]
21    Protocol(#[from] ProtocolError),
22
23    /// A filesystem read or write failed — [`Document::open`](crate::Document::open)
24    /// (including a file that is not valid UTF-8) or a save.
25    #[error("io: {0}")]
26    Io(#[from] std::io::Error),
27
28    /// [`Document::undo`](crate::Document::undo) with an empty undo stack.
29    #[error("nothing to undo")]
30    NothingToUndo,
31
32    /// [`Document::redo`](crate::Document::redo) with an empty redo stack.
33    #[error("nothing to redo")]
34    NothingToRedo,
35
36    /// [`Document::save`](crate::Document::save) on a document with no path.
37    #[error("document has no path; use save_as")]
38    NoPath,
39
40    /// A long-running operation was interrupted by a flipped
41    /// [`lattice_protocol::CancellationToken`]. Bubbles up from
42    /// the search hot loops so callers (grammar dispatcher,
43    /// substitute) can map it to their domain-specific error.
44    #[error("operation cancelled")]
45    Cancelled,
46}
47
48/// `Result` specialised to [`CoreError`].
49pub type CoreResult<T> = Result<T, CoreError>;
lattice_core/error.rs

lattice_core/
error.rs
