Use slotmap instead of bespoke arena, limiting to one parent only (#196)
1//! The Error types produced by Taffy.
2#[cfg(feature = "std")]
3use core::fmt::{Display, Formatter, Result};
4
5use crate::node::Node;
6
7/// The error Taffy generates on invalid operations
8pub type TaffyResult<T> = core::result::Result<T, TaffyError>;
9
10/// An error that occurs while trying to access or modify a [`Node`]'s children by index.
11#[derive(Debug)]
12pub enum TaffyError {
13 /// The parent [`Node`] does not have a child at `child_index`. It only has `child_count` children
14 ChildIndexOutOfBounds {
15 /// The parent node whose child was being looked up
16 parent: Node,
17 /// The index that was looked up
18 child_index: usize,
19 /// The total number of children the parent has
20 child_count: usize,
21 },
22 /// The parent [`Node`] was not found in the [`Taffy`](crate::Taffy) instance.
23 InvalidParentNode(Node),
24 /// The child [`Node`] was not found in the [`Taffy`](crate::Taffy) instance.
25 InvalidChildNode(Node),
26 /// The supplied [`Node`] was not found in the [`Taffy`](crate::Taffy) instance.
27 InvalidInputNode(Node),
28}
29
30#[cfg(feature = "std")]
31impl Display for TaffyError {
32 fn fmt(&self, f: &mut Formatter) -> Result {
33 match self {
34 TaffyError::ChildIndexOutOfBounds { parent, child_index, child_count } => write!(
35 f,
36 "Index (is {}) should be < child_count ({}) for parent node {:?}",
37 child_index, child_count, parent
38 ),
39 TaffyError::InvalidParentNode(parent) => {
40 write!(f, "Parent Node {:?} is not in the Taffy instance", parent)
41 }
42 TaffyError::InvalidChildNode(child) => write!(f, "Child Node {:?} is not in the Taffy instance", child),
43 TaffyError::InvalidInputNode(node) => write!(f, "Supplied Node {:?} is not in the Taffy instance", node),
44 }
45 }
46}
47
48#[cfg(feature = "std")]
49impl std::error::Error for TaffyError {}