Struct EncodeContext 

pub struct EncodeContext<'a, Value> { /* private fields */ }

Read-only context supplied to an encode policy hook.

The engine retains ownership of the mutable output slice. Hooks can inspect the current value and cursor/capacity metadata, then return an crate::engine::EncodeUnencodableAction without being able to mutate output behind the engine’s progress accounting.

In a codec-backed converter, values emitted by source decode reset or finish have no source-unit position and use placeholder index 0. Ordinary decoded values retain their index in the input slice supplied to the decode call that produced them. A pending value keeps that index across calls; it is not rebased to a later input slice and is not a whole-stream offset. The retained index may be outside the bounds of a later input slice.

Type Parameters

• Value: Logical input value type.

Examples

use qubit_codec::engine::EncodeContext;

let value = 7_u8;
let context = EncodeContext::new(&value, 0, 0, 1);
assert_eq!(context.input_value(), &7);

Implementations

impl<'a, Value> EncodeContext<'a, Value>

pub const fn new( input_value: &'a Value, input_index: usize, output_index: usize, available_output: usize, ) -> Self

Creates an encode policy context.

Parameters

• input_value: Borrowed input value being encoded.
• input_index: Input index of input_value; converter lifecycle- generated values use placeholder 0 because they have no source-unit position.
• output_index: Absolute output index where writing begins.
• available_output: Output units writable from output_index.

Returns

Returns a read-only encode context.

pub const fn input_value(&self) -> &Value

Returns the input value being encoded.

Returns

The input value borrowed through this context without allocation.

pub const fn input_index(&self) -> usize

Returns the input index of the current value.

In a codec-backed converter, lifecycle-generated values use placeholder index 0 because they have no source-unit position. Ordinary decoded values retain their index in the input slice supplied to the decode call that produced them. A pending value keeps that index across calls; it is not rebased to a later input slice and is not a whole-stream offset. The retained index may be outside the bounds of a later input slice.

Returns

The value’s input index, including placeholder 0 for converter lifecycle-generated values.

pub const fn output_index(&self) -> usize

Returns the absolute output index where writing begins.

Returns

The starting output cursor for this encode attempt.

pub const fn available_output(&self) -> usize

Returns output capacity visible to this encode attempt.

Returns

The number of output units available from the starting cursor.

Trait Implementations

impl<'a, Value: Clone> Clone for EncodeContext<'a, Value>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a, Value: Copy> Copy for EncodeContext<'a, Value>

impl<'a, Value: Debug> Debug for EncodeContext<'a, Value>

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

Formats the value using the given formatter.

impl<'a, Value: Eq> Eq for EncodeContext<'a, Value>

impl<'a, Value: Hash> Hash for EncodeContext<'a, Value>

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<'a, Value: PartialEq> PartialEq for EncodeContext<'a, Value>

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

Equality operator ==.

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

Inequality operator !=.

impl<'a, Value: PartialEq> StructuralPartialEq for EncodeContext<'a, Value>