Struct Kp 

pub struct Kp<R, V, Root, Value, MutRoot, MutValue, G, S>
where
    Root: Borrow<R>,
    MutRoot: BorrowMut<R>,
    MutValue: BorrowMut<V>,
    G: Fn(Root) -> Option<Value>,
    S: Fn(MutRoot) -> Option<MutValue>,
{
    pub get: G,
    pub set: S,
    pub _p: PhantomData<(R, V, Root, Value, MutRoot, MutValue)>,
}

Kp — typed keypath with getter/setter closures. See also AKp for type-erased keypaths.

Mutation: get vs get_mut (setter path)

• get uses the get closure (getter): Fn(Root) -> Option<Value>
• get_mut uses the set closure (setter): Fn(MutRoot) -> Option<MutValue>

When mutating through a Kp, the setter path is used—get_mut invokes the set closure, not the get closure. The getter is for read-only access only.

For manual reference-shaped paths, constrain_get and constrain_set help closures satisfy for<'b> Fn(&'b R) -> Option<&'b V>; use Kp::get_ref / Kp::get_mut_ref to call them explicitly.

Fields

get: G

Getter closure: used by Kp::get for read-only access when G satisfies the HRTB.

set: S

Setter closure: used by Kp::get_mut for mutation when S satisfies the HRTB.

_p: PhantomData<(R, V, Root, Value, MutRoot, MutValue)>

Implementations

impl<'a, R, V> Kp<R, V, &'a R, &'a V, &'a mut R, &'a mut V, for<'b> fn(&'b R) -> Option<&'b V>, for<'b> fn(&'b mut R) -> Option<&'b mut V>>

pub fn to_dynamic(self) -> KpDynamic<R, V>

Converts this keypath to KpDynamic for dynamic dispatch and storage (e.g. in a struct field).

impl<R, V, Root, Value, MutRoot, MutValue, G, S> Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value> + Send + Sync + 'static, S: Fn(MutRoot) -> Option<MutValue> + Send + Sync + 'static, R: 'static, V: 'static,

pub fn into_dynamic(self) -> KpDynamic<R, V>

Erases getter/setter type into KpDynamic so you can store composed paths (e.g. after KpTrait::then).

#[derive(Kp)] methods return KpType (fn pointers); chaining with .then() produces opaque closures. Neither matches a fixed KpType<…> field type—use KpDynamic<R, V> and .into_dynamic() (or KpType::to_dynamic for a single segment).

Safety

This uses a small amount of unsafe internally: it re-interprets &R / &mut R as Root / MutRoot. That matches every Kp built from this crate’s public API (Kp::new on reference-shaped handles, #[derive(Kp)], and KpTrait::then / Kp::then on those paths). Do not call this on a custom Kp whose Root / MutRoot are not layout-compatible with &R / &mut R or whose getters keep borrows alive past the call.

impl<R, V> Kp<R, V, &'static R, &'static V, &'static mut R, &'static mut V, Box<dyn for<'b> Fn(&'b R) -> Option<&'b V> + Send + Sync>, Box<dyn for<'b> Fn(&'b mut R) -> Option<&'b mut V> + Send + Sync>>

pub fn from_closures<G, S>(get: G, set: S) -> Self

where G: for<'b> Fn(&'b R) -> Option<&'b V> + Send + Sync + 'static, S: for<'b> Fn(&'b mut R) -> Option<&'b mut V> + Send + Sync + 'static,

Build a keypath from two closures (e.g. when they capture a variable like an index). Same pattern as Kp::new in lock.rs; use this when the keypath captures variables.

impl<R, V, Root, Value, MutRoot, MutValue, G, S> Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

pub fn new(get: G, set: S) -> Self

pub fn get(&self, root: Root) -> Option<Value>

Read through the getter closure. For reference-shaped keypaths built with constrain_get / constrain_set, you can also call this as kp.get(root) with root: Root (often &R).

pub fn get_mut(&self, root: MutRoot) -> Option<MutValue>

Mutate through the setter closure.

pub fn get_ref<'a>(&self, root: &'a R) -> Option<&'a V>

where G: for<'b> Fn(&'b R) -> Option<&'b V>,

Higher-ranked read when G: for<'b> Fn(&'b R) -> Option<&'b V> (e.g. manual keypaths using constrain_get). Prefer get for generic Kp including mapped values.

pub fn get_mut_ref<'a>(&self, root: &'a mut R) -> Option<&'a mut V>

where S: for<'b> Fn(&'b mut R) -> Option<&'b mut V>,

Higher-ranked write when S: for<'b> Fn(&'b mut R) -> Option<&'b mut V>.

pub fn then<SV, G2, S2>( self, next: Kp<V, SV, &'static V, &'static SV, &'static mut V, &'static mut SV, G2, S2>, ) -> Kp<R, SV, &'static R, &'static SV, &'static mut R, &'static mut SV, impl for<'b> Fn(&'b R) -> Option<&'b SV>, impl for<'b> Fn(&'b mut R) -> Option<&'b mut SV>>

where G: for<'b> Fn(&'b R) -> Option<&'b V>, S: for<'b> Fn(&'b mut R) -> Option<&'b mut V>, G2: for<'b> Fn(&'b V) -> Option<&'b SV>, S2: for<'b> Fn(&'b mut V) -> Option<&'b mut SV>,

impl<R, Root, MutRoot, G, S> Kp<R, R, Root, Root, MutRoot, MutRoot, G, S>

where Root: Borrow<R>, MutRoot: BorrowMut<R>, G: Fn(Root) -> Option<Root>, S: Fn(MutRoot) -> Option<MutRoot>,

pub fn identity_typed() -> Kp<R, R, Root, Root, MutRoot, MutRoot, fn(Root) -> Option<Root>, fn(MutRoot) -> Option<MutRoot>>

pub fn identity<'a>() -> KpType<'a, R, R>

Trait Implementations

impl<R, V, Root, Value, MutRoot, MutValue, G, S> AccessorTrait<R, V, Root, Value, MutRoot, MutValue, G, S> for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

fn get_optional(&self, root: Option<Root>) -> Option<Value>

Like get, but takes an optional root: returns None if root is None, otherwise the result of the getter.

fn get_mut_optional(&self, root: Option<MutRoot>) -> Option<MutValue>

Like get_mut, but takes an optional root: returns None if root is None, otherwise the result of the setter.

fn get_or_else<F>(&self, root: Root, f: F) -> Value

where F: FnOnce() -> Value,

Returns the value if the keypath succeeds, otherwise calls f and returns its result.

fn get_mut_or_else<F>(&self, root: MutRoot, f: F) -> MutValue

where F: FnOnce() -> MutValue,

Returns the mutable value if the keypath succeeds, otherwise calls f and returns its result.

impl<R, V, Root, Value, MutRoot, MutValue, G, S> ChainExt<R, V, Root, Value, MutRoot, MutValue> for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

fn then_lock<Lock, Mid, V2, LockValue, MidValue, Value2, MutLock, MutMid, MutValue2, G1, S1, L, G2, S2>( self, lock_kp: LockKp<V, Lock, Mid, V2, Value, LockValue, MidValue, Value2, MutValue, MutLock, MutMid, MutValue2, G1, S1, L, G2, S2>, ) -> KpThenLockKp<R, V, V2, Root, Value, Value2, MutRoot, MutValue, MutValue2, Self, LockKp<V, Lock, Mid, V2, Value, LockValue, MidValue, Value2, MutValue, MutLock, MutMid, MutValue2, G1, S1, L, G2, S2>>

where V: 'static + Clone, V2: 'static, Value: Borrow<V>, Value2: Borrow<V2>, MutValue: BorrowMut<V>, MutValue2: BorrowMut<V2>, LockValue: Borrow<Lock>, MidValue: Borrow<Mid>, MutLock: BorrowMut<Lock>, MutMid: BorrowMut<Mid>, G1: Fn(Value) -> Option<LockValue>, S1: Fn(MutValue) -> Option<MutLock>, L: LockAccess<Lock, MidValue> + LockAccess<Lock, MutMid>, G2: Fn(MidValue) -> Option<Value2>, S2: Fn(MutMid) -> Option<MutValue2>,

Chain with a sync crate::lock::LockKp. Use .get(root) / .get_mut(root) on the returned keypath.

fn then_async<AsyncKp>( self, async_kp: AsyncKp, ) -> KpThenAsyncKeyPath<R, V, <AsyncKp::Value as KeyPathValueTarget>::Target, Root, Value, AsyncKp::Value, MutRoot, MutValue, AsyncKp::MutValue, Self, AsyncKp>

where Value: Borrow<V>, MutValue: BorrowMut<V>, AsyncKp: AsyncKeyPathLike<Value, MutValue>, AsyncKp::Value: KeyPathValueTarget + Borrow<<AsyncKp::Value as KeyPathValueTarget>::Target>, AsyncKp::MutValue: BorrowMut<<AsyncKp::Value as KeyPathValueTarget>::Target>, <AsyncKp::Value as KeyPathValueTarget>::Target: 'static,

Chain with an async keypath (e.g. crate::async_lock::AsyncLockKp). Use .get(&root).await on the returned keypath.

impl<R: Clone, V: Clone, Root, Value: Clone, MutRoot, MutValue, G, S> Clone for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R> + Clone, MutRoot: BorrowMut<R> + Clone, MutValue: BorrowMut<V> + Clone, G: Fn(Root) -> Option<Value> + Clone, S: Fn(MutRoot) -> Option<MutValue> + Clone,

fn clone(&self) -> Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<R, V, Root, Value, MutRoot, MutValue, G, S> CoercionTrait<R, V, Root, Value, MutRoot, MutValue, G, S> for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

fn into_set(self) -> impl Fn(MutRoot) -> Option<MutValue>

set fn is converting fn pointer to Fn closure

fn into_get(self) -> impl Fn(Root) -> Option<Value>

get fn is converting fn pointer to Fn closure

fn for_arc<'b>( &self, ) -> Kp<Arc<R>, V, Arc<R>, Value, Arc<R>, MutValue, impl Fn(Arc<R>) -> Option<Value>, impl Fn(Arc<R>) -> Option<MutValue>>

where R: 'b, V: 'b, Root: for<'a> From<&'a R>, MutRoot: for<'a> From<&'a mut R>,

fn for_box<'a>( &self, ) -> Kp<Box<R>, V, Box<R>, Value, Box<R>, MutValue, impl Fn(Box<R>) -> Option<Value>, impl Fn(Box<R>) -> Option<MutValue>>

where R: 'a, V: 'a, Root: for<'b> From<&'b R>, MutRoot: for<'b> From<&'b mut R>,

impl<R, V, Root, Value, MutRoot, MutValue, G, S> Debug for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

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

Formats the value using the given formatter.

impl<R, V, Root, Value, MutRoot, MutValue, G, S> Display for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

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

Formats the value using the given formatter.

impl<'a, R, V> From<Kp<R, V, &'a R, &'a V, &'a mut R, &'a mut V, for<'b> fn(&'b R) -> Option<&'b V>, for<'b> fn(&'b mut R) -> Option<&'b mut V>>> for KpDynamic<R, V>

fn from(kp: KpType<'a, R, V>) -> Self

Converts to this type from the input type.

impl<R, V, Root, Value, MutRoot, MutValue, G, S> HofTrait<R, V, Root, Value, MutRoot, MutValue, G, S> for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

fn map<MappedValue, F>( &self, mapper: F, ) -> Kp<R, MappedValue, Root, MappedValue, MutRoot, MappedValue, impl Fn(Root) -> Option<MappedValue> + '_, impl Fn(MutRoot) -> Option<MappedValue> + '_>

where F: Fn(&V) -> MappedValue + Copy + 'static, MappedValue: 'static,

Map the value through a transformation function.

fn filter<F>( &self, predicate: F, ) -> Kp<R, V, Root, Value, MutRoot, MutValue, impl Fn(Root) -> Option<Value> + '_, impl Fn(MutRoot) -> Option<MutValue> + '_>

where F: Fn(&V) -> bool + Copy + 'static,

Filter the value based on a predicate.

fn filter_map<MappedValue, F>( &self, mapper: F, ) -> Kp<R, MappedValue, Root, MappedValue, MutRoot, MappedValue, impl Fn(Root) -> Option<MappedValue> + '_, impl Fn(MutRoot) -> Option<MappedValue> + '_>

where F: Fn(&V) -> Option<MappedValue> + Copy + 'static,

Map and flatten when mapper returns an Option.

fn inspect<F>( &self, inspector: F, ) -> Kp<R, V, Root, Value, MutRoot, MutValue, impl Fn(Root) -> Option<Value> + '_, impl Fn(MutRoot) -> Option<MutValue> + '_>

where F: Fn(&V) + Copy + 'static,

Apply a function for its side effects and return the value.

fn flat_map<I, Item, F>(&self, mapper: F) -> impl Fn(Root) -> Vec<Item> + '_

where F: Fn(&V) -> I + 'static, I: IntoIterator<Item = Item>,

Flat map - maps to an iterator and flattens.

fn fold_value<Acc, F>(&self, init: Acc, folder: F) -> impl Fn(Root) -> Acc + '_

where F: Fn(Acc, &V) -> Acc + 'static, Acc: Copy + 'static,

Fold/reduce the value using an accumulator function.

fn any<F>(&self, predicate: F) -> impl Fn(Root) -> bool + '_

where F: Fn(&V) -> bool + 'static,

Check if any element satisfies a predicate.

fn all<F>(&self, predicate: F) -> impl Fn(Root) -> bool + '_

where F: Fn(&V) -> bool + 'static,

Check if all elements satisfy a predicate.

fn count_items<F>(&self, counter: F) -> impl Fn(Root) -> Option<usize> + '_

where F: Fn(&V) -> usize + 'static,

Count elements in a collection value.

fn find_in<Item, F>(&self, finder: F) -> impl Fn(Root) -> Option<Item> + '_

where F: Fn(&V) -> Option<Item> + 'static,

Find first element matching predicate in a collection value.

fn take<Output, F>( &self, n: usize, taker: F, ) -> impl Fn(Root) -> Option<Output> + '_

where F: Fn(&V, usize) -> Output + 'static,

Take first N elements from a collection value.

fn skip<Output, F>( &self, n: usize, skipper: F, ) -> impl Fn(Root) -> Option<Output> + '_

where F: Fn(&V, usize) -> Output + 'static,

Skip first N elements from a collection value.

fn partition_value<Output, F>( &self, partitioner: F, ) -> impl Fn(Root) -> Option<Output> + '_

where F: Fn(&V) -> Output + 'static,

Partition a collection value into two groups based on predicate.

fn min_value<Item, F>(&self, min_fn: F) -> impl Fn(Root) -> Option<Item> + '_

where F: Fn(&V) -> Option<Item> + 'static,

Get min value from a collection.

fn max_value<Item, F>(&self, max_fn: F) -> impl Fn(Root) -> Option<Item> + '_

where F: Fn(&V) -> Option<Item> + 'static,

Get max value from a collection.

fn sum_value<Sum, F>(&self, sum_fn: F) -> impl Fn(Root) -> Option<Sum> + '_

where F: Fn(&V) -> Sum + 'static,

Sum numeric values in a collection.

impl<R, V, Root, Value, MutRoot, MutValue, G, S> KpTrait<R, V, Root, Value, MutRoot, MutValue, G, S> for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

fn then<SV, SubValue, MutSubValue, G2, S2>( self, next: Kp<V, SV, Value, SubValue, MutValue, MutSubValue, G2, S2>, ) -> Kp<R, SV, Root, SubValue, MutRoot, MutSubValue, impl Fn(Root) -> Option<SubValue>, impl Fn(MutRoot) -> Option<MutSubValue>>

where SubValue: Borrow<SV>, MutSubValue: BorrowMut<SV>, G2: Fn(Value) -> Option<SubValue>, S2: Fn(MutValue) -> Option<MutSubValue>,

fn get(&self, root: Root) -> Option<Value>

fn get_mut(&self, root: MutRoot) -> Option<MutValue>

fn type_id_of_root() -> TypeId

where R: 'static,

fn type_id_of_value() -> TypeId

where V: 'static,

impl<R, V, Root, Value, MutRoot, MutValue, G, S> SyncKeyPathLike<Root, Value, MutRoot, MutValue> for Kp<R, V, Root, Value, MutRoot, MutValue, G, S>

where Root: Borrow<R>, Value: Borrow<V>, MutRoot: BorrowMut<R>, MutValue: BorrowMut<V>, G: Fn(Root) -> Option<Value>, S: Fn(MutRoot) -> Option<MutValue>,

fn sync_get(&self, root: Root) -> Option<Value>

Get an immutable reference through the keypath (sync, non-blocking).

fn sync_get_mut(&self, root: MutRoot) -> Option<MutValue>

Get a mutable reference through the keypath (sync, non-blocking).