Enum DecodeFailure 

pub enum DecodeFailure<E> {
    #[non_exhaustive]
    Incomplete {
        source: Option<E>,
        required_total: NonZeroUsize,
    },
    #[non_exhaustive]
    Invalid {
        source: E,
        consumed: Option<NonZeroUsize>,
    },
}

Failure reported by crate::Codec::decode.

This type separates stream-control failures from codec-domain failures. Incomplete tells buffered adapters to preserve the current input tail and request more units. Invalid carries the codec-specific malformed, non-canonical, or otherwise invalid input error with a known non-zero consumption length, or with unknown consumption when set to None.

Type Parameters

• E: Codec-specific invalid-input error type.

Variants

#[non_exhaustive]

Incomplete

The visible input is a valid prefix but not enough to decode a value.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

source: Option<E>

Codec-specific context for the incomplete prefix, when available.

Stream drivers may ignore this field while retrying input. Once the stream reaches EOF, adapters can use it to preserve detailed diagnostics instead of reconstructing an error from the length bound alone.

required_total: NonZeroUsize

Current non-zero minimum total units required before retrying from the value start.

A later retry may raise this lower bound after the codec sees a longer prefix.

#[non_exhaustive]

Invalid

The input is invalid for the codec.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

source: E

Codec-specific invalid-input error.

consumed: Option<NonZeroUsize>

Invalid units that may be consumed by a non-strict policy, when known.

Implementations

impl<E> DecodeFailure<E>

pub const fn incomplete(required_total: NonZeroUsize) -> Self

Creates an incomplete-input decode failure.

Parameters

• required_total: Current non-zero minimum total units required before retrying from the value start. A later retry may raise this lower bound.

Returns

Returns an incomplete decode failure.

pub const fn incomplete_with_source( source: E, required_total: NonZeroUsize, ) -> Self

Creates an incomplete-input decode failure with codec-specific context.

Parameters

• source: Codec-specific error describing the visible incomplete prefix.
• required_total: Current non-zero minimum units required before retrying from the value start.

Returns

Returns an incomplete decode failure retaining source for adapters that need detailed EOF diagnostics.

pub const fn invalid(source: E, consumed: NonZeroUsize) -> Self

Creates an invalid-input decode failure with a consumption hint.

Parameters

• source: Codec-specific invalid-input error.
• consumed: Invalid input units that may be consumed.

Returns

Returns an invalid decode failure.

pub const fn invalid_unknown(source: E) -> Self

Creates an invalid-input decode failure with unknown consumption.

Parameters

• source: Codec-specific invalid-input error.

Returns

Returns an invalid decode failure.

pub const fn required_total(&self) -> Option<NonZeroUsize>

Returns the current minimum input length required before retrying an incomplete prefix.

Returns

Returns Some(required_total) for incomplete failures, where the value is a lower bound that a later retry may raise, or None for invalid-input failures.

pub const fn incomplete_source(&self) -> Option<&E>

Borrows the codec-specific error retained for an incomplete prefix.

Returns

Returns Some(source) when the codec supplied incomplete-input context, or None when the failure only carries the retry bound.

pub const fn invalid_source(&self) -> Option<&E>

Borrows the codec-specific invalid-input error.

Returns

Returns Some(source) for invalid-input failures, or None for incomplete failures.

pub const fn consumed_units(&self) -> Option<NonZeroUsize>

Returns invalid units that may be consumed by a non-strict policy.

Returns

Returns Some(consumed) for Invalid, or None when the failure is incomplete or invalid with unknown consumption.

Trait Implementations

impl<E: Clone> Clone for DecodeFailure<E>

fn clone(&self) -> DecodeFailure<E>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<E: Copy> Copy for DecodeFailure<E>

impl<E: Debug> Debug for DecodeFailure<E>

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

Formats the value using the given formatter.

impl<E: Eq> Eq for DecodeFailure<E>

impl<E: Hash> Hash for DecodeFailure<E>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<E: PartialEq> PartialEq for DecodeFailure<E>

fn eq(&self, other: &DecodeFailure<E>) -> bool

Equality operator ==.

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

Inequality operator !=.

impl<E: PartialEq> StructuralPartialEq for DecodeFailure<E>