Struct StateProjection 

pub struct StateProjection<'a> { /* private fields */ }

A stable, keyed declaration of mutable array state.

Required and optional slots are declared once. All derived views use the same sorted keys and preserve whether every optional slot is present.

Implementations

impl<'a> StateProjection<'a>

pub fn new() -> Self

Create an empty projection.

pub fn required( &mut self, key: impl Into<Rc<str>>, value: &'a mut Array, ) -> Result<(), StateProjectionError>

Declare a required keyed slot.

pub fn optional( &mut self, key: impl Into<Rc<str>>, value: &'a mut Option<Array>, ) -> Result<(), StateProjectionError>

Declare an optional keyed slot, retaining its key when the value is absent.

pub fn len(&self) -> usize

Return the number of declared slots, including absent optional slots.

pub fn is_empty(&self) -> bool

Return whether no slots are declared.

pub fn present_len(&self) -> usize

Return the number of currently present arrays.

pub fn values(&self) -> impl Iterator<Item = &Array>

Traverse present arrays in stable key order.

pub fn values_mut(&mut self) -> impl Iterator<Item = &mut Array> + use<'_, 'a>

Traverse present arrays mutably in stable key order.

pub fn iter(&self) -> impl Iterator<Item = (&str, Option<&Array>)>

Traverse every key and optional-presence tag in stable key order.

pub fn iter_mut( &mut self, ) -> impl Iterator<Item = (&str, Option<&mut Array>)> + use<'_, 'a>

Traverse every key and mutable optional-presence tag in stable key order.

pub fn into_entries(self) -> impl Iterator<Item = (Rc<str>, &'a Array)>

Consume the projection into present immutable entries in stable key order.

pub fn into_entries_mut(self) -> impl Iterator<Item = (Rc<str>, &'a mut Array)>

Consume the projection into present mutable entries in stable key order.

pub fn snapshot(&self) -> StateSnapshot

Capture every declared key and optional-presence tag.

pub fn layout(&self) -> Vec<StateLayoutEntry>

Derive the key, presence, dtype, and shape layout.

pub fn restore( &mut self, snapshot: StateSnapshot, reset_new: bool, ) -> Result<(), StateProjectionError>

Restore a keyed snapshot.

When reset_new is true, slots created after the snapshot are retained and zeroed. All other keys and optional-presence tags are restored exactly.

Trait Implementations

impl<'a> Debug for StateProjection<'a>

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

Formats the value using the given formatter.

impl Default for StateProjection<'_>

fn default() -> Self

Returns the “default value” for a type.