symbios_shape/error.rs
1//! Error type returned by the parser and the interpreter.
2//!
3//! Every fallible API in this crate returns `Result<T, ShapeError>`. Variants
4//! cover three broad failure classes:
5//!
6//! - **Parse failures** — `ParseError` carries a human-readable message from
7//! the nom parser, including the offending input span.
8//! - **Numeric / structural validation** — `InvalidNumericValue`,
9//! `EmptySplit`, `InvalidFloatingSize`, `SplitOverflow`, `NoFloatingSlots`,
10//! `UnknownCompSelector`, `OffsetTooLarge`, `InvalidRoofAngle`,
11//! `InvalidAlignTarget` are raised when a parsed grammar would produce
12//! geometry that isn't well-defined.
13//! - **DoS safety caps** — `CapacityOverflow` and `DepthLimitExceeded` are
14//! returned when a grammar exceeds the engine's bounded queue, terminal,
15//! op-count, identifier, or recursion limits rather than allowing
16//! unbounded resource use.
17
18use thiserror::Error;
19
20/// All errors produced by the parser and the interpreter.
21///
22/// See the module-level documentation for a categorised overview.
23#[derive(Error, Debug, PartialEq)]
24pub enum ShapeError {
25 #[error("Parse error: {0}")]
26 ParseError(String),
27 #[error("Non-finite numeric value detected (NaN/Inf)")]
28 InvalidNumericValue,
29 #[error("Scope capacity overflow")]
30 CapacityOverflow,
31 #[error("Split sizes are empty")]
32 EmptySplit,
33 #[error("Split floating size must be positive: {0}")]
34 InvalidFloatingSize(f64),
35 #[error("Split absolute sizes exceed scope dimension {0}")]
36 SplitOverflow(f64),
37 #[error("No floating slots to absorb remainder in split")]
38 NoFloatingSlots,
39 #[error("Comp selector '{0}' not recognised")]
40 UnknownCompSelector(String),
41 #[error("Derivation depth limit {0} exceeded")]
42 DepthLimitExceeded(usize),
43 #[error("Internal error: {0}")]
44 Internal(String),
45 #[error("Offset inset distance exceeds scope dimension")]
46 OffsetTooLarge,
47 #[error("Roof angle must be in (0°, 90°): got {0}")]
48 InvalidRoofAngle(f64),
49 #[error("Align target vector must be non-zero")]
50 InvalidAlignTarget,
51}