Enum Traversal

pub enum Traversal {
    Absent(usize),
    TooShort(usize),
    NotFound(usize),
    TooLong(usize),
    Access(usize, &'static str),
    Invalid(usize, &'static str),
}

Errors that can occur when using the Tree traits.

A usize member indicates the key depth where the error occurred. The depth here is the number of names or indices consumed. It is also the number of separators in a path or the length of an indices slice. The TreeKey<Y> recursion depth is an upper bound to the key depth here but not equivalent.

If multiple errors are applicable simultaneously the precedence is as per the order in the enum definition (from high to low).

Variants

Absent(usize)

A node does not exist at runtime.

An enum variant in the tree towards the node is currently absent. This is for example the case if an Option using the Tree* traits is None at runtime. See also crate::TreeKey.

TooShort(usize)

The key ends early and does not reach a leaf node.

NotFound(usize)

The key was not found (index parse failure or too large, name not found or invalid).

TooLong(usize)

The key is too long and goes beyond a leaf node.

Access(usize, &'static str)

A node could not be accessed.

The get or get_mut accessor returned an error message.

Invalid(usize, &'static str)

A deserialized leaf value was found to be invalid.

The validate callback returned an error message.

Implementations

impl Traversal

pub fn increment(self) -> Self

Pass it up one hierarchy depth level, incrementing its usize depth field by one.

pub fn depth(&self) -> &usize

Return the traversal depth

Trait Implementations

impl Clone for Traversal

fn clone(&self) -> Traversal

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Traversal

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Traversal

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for Traversal

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl<E> From<Traversal> for Error<E>

fn from(value: Traversal) -> Self

Converts to this type from the input type.

impl PartialEq for Traversal

fn eq(&self, other: &Traversal) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<E> TryFrom<Error<E>> for Traversal

type Error = Error<E>

The type returned in the event of a conversion error.

fn try_from(value: Error<E>) -> Result<Self, Self::Error>

Performs the conversion.

impl Copy for Traversal

impl Eq for Traversal

impl StructuralPartialEq for Traversal