Struct PartialGetterImpl 

pub struct PartialGetterImpl<S, A, PG: PartialGetter<S, A>>(pub PG, _);

A wrapper of the PartialGetter optic implementations, encapsulating a partial getter function.

PartialGetterImpl provides a way to define partial getters - optics that attempt to retrieve a value of type A from a source of type S, potentially failing with an error. This struct is particularly useful in scenarios where you need to compose or reuse getter logic that might not always succeed.

Note

This struct is not intended to be created by users directly, but it implements a From<PartialGetter<S,A>> so that implementors of new optic types can wrap their concrete implementation of a PartialGetter optic.

Type Parameters

• S: The source type from which the value is to be retrieved.
• A: The target type of the value to be retrieved.

See Also

• PartialGetter trait for defining custom partial getters.
• [mapped_partial_getter] function for creating PartialGetterImpl instances from mapping functions.

Tuple Fields

0: PG

Implementations

impl<S, I, PG1: PartialGetter<S, I>> PartialGetterImpl<S, I, PG1>

pub fn compose_with_partial_getter<E, A, PG2: PartialGetter<I, A>>( self, other: PartialGetterImpl<I, A, PG2>, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A, GetterError = E>>

where PG1::GetterError: Into<E>, PG2::GetterError: Into<E>,

Composes this PartialGetterImpl<S,I> with a PartialGetter<I,A>, resulting in a new PartialGetterImpl<S, A> that focuses through both optics sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If either optics fails to focus, the composition will fail to focus.

Type Parameters

• E: The error type for the composed partial getter, which must should be able to be constructed from both P1::GetterError and PG2::GetterError through Into::into.
• A: The target type of the composed optic.
• PG2: The type of the partial getter to compose with.

Parameters

• other: The partial getter to compose with.

Returns

A new PartialGetterImpl that represents the composition of self and other.

Note

This method uses Into::into to convert the errors from both prisms into the common error type E. If you need custom error mapping, consider using compose_with_partial_getter_with_mappers.

pub fn compose_with_partial_getter_with_mappers<E, A, PG2: PartialGetter<I, A>>( self, other: PartialGetterImpl<I, A, PG2>, error_mapper_1: fn(PG1::GetterError) -> E, error_mapper_2: fn(PG2::GetterError) -> E, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A>>

Composes this PartialGetterImpl<S,I> with a PartialGetter<I,A>, resulting in a new PartialGetter<S, A> that focuses through both optics sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If either optics fails to focus, the composition will fail to focus.

Type Parameters

• E: The common error type for the composed partial_getter.
• A: The target type of the composed prism.

Parameters

• other: The partial getter to compose with.
• error_mapper1: A function to map PG1::GetterError into E.
• error_mapper2: A function to map PG2::GetterError into E.

Returns

A new PartialGetterImpl that represents the composition of self and other with custom error mapping.

Note

This method is similar to compose_with_partial_getter, but provides the ability to specify custom functions to map the errors from each optic into a common error type.

pub fn compose_with_getter<A, G2: Getter<I, A>>( self, other: GetterImpl<I, A, G2>, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A>>

Composes this PartialGetterImpl<S,I> with a GetterImpl<I,A>, resulting in a new PartialGetterImpl<S, A> that focuses through both optics sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If the first optic fails to focus, the composition will fail to focus.

Type Parameters

• A: The target type of the composed optic.
• G2: The type of the getter to compose with.

Parameters

• other: The getter to compose with.

Returns

A new PartialGetterImpl that represents the composition of self and other.

pub fn compose_with_setter<A, S2: Setter<I, A>>( self, _other: SetterImpl<I, A, S2>, ) -> !

where PG1: Prism<S, I>,

Impossible to combine

Panics

always

pub fn compose_with_prism<E, A, P2: Prism<I, A>>( self, other: PrismImpl<I, A, P2>, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A>>

where PG1::GetterError: Into<E>, P2::GetterError: Into<E>,

Composes this PartialGetterImpl<S,I> with another Prism<I,A>, resulting in a new PartialGetterImpl<S, A> that focuses through both prisms sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If either optics fails to match, the composition will fail.

Type Parameters

• E: The error type for the composed partial getter, which must should be able to be constructed from both P1::GetterError and P2::GetterError through Into::into.
• A: The target type of the composed prism.
• P2: The type of the prism to compose with.

Parameters

• other: The prism to compose with.

Returns

A new PartialGetterImpl that represents the composition of self and other.

Note

This method uses Into::into to convert the errors from both prisms into the common error type E. If you need custom error mapping, consider using compose_with_prism_with_mappers.

pub fn compose_with_prism_with_mappers<E, A, P2: Prism<I, A>>( self, other: PrismImpl<I, A, P2>, error_mapper_1: fn(PG1::GetterError) -> E, error_mapper_2: fn(P2::GetterError) -> E, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A>>

Composes this PartialGetterImpl<S,I> with a PrismImpl<I,A>, resulting in a new PartialGetterImpl<S, A> that focuses through both prisms sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If either optics fails to match, the composition will fail.

Type Parameters

• E: The common error type for the composed prism.
• A: The target type of the composed prism.

Parameters

• other: The second prism to compose with.
• error_mapper1: A function to map PG1::GetterError into E.
• error_mapper2: A function to map P2::GetterError into E.

Returns

A new PartialGetterImpl that represents the composition of self and other with custom error mapping.

Note

This method is similar to compose_with_prism, but provides the ability to specify custom functions to map the errors from each prism into a common error type.

pub fn compose_with_lens<A, L2: Lens<I, A>>( self, other: LensImpl<I, A, L2>, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A>>

Composes this PartialGetterImpl<S,I> with a Lens<I,A>, resulting in a new PartialGetterImpl<S, A> that focuses through both optics sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If the partial getter fails to match, the composition will fail.

Type Parameters

• A: The target type of the composed prism.
• L2: The type of the lens to compose with.

Parameters

• other: The lens to compose with.

Returns

A new PartialGetterImpl that represents the composition of self and other

pub fn compose_with_fallible_iso<E, A, FI2: FallibleIso<I, A>>( self, other: FallibleIsoImpl<I, A, FI2>, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A>>

where E: From<FI2::GetterError> + From<PG1::GetterError>,

Composes this PartialGetterImpl<S,I> with a FallibleIso<I,A>, resulting in a new PartialGetterImpl<S, A> that focuses through both optics sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If either optics fails to match, the composition will fail.

Type Parameters

• E: The error type for the composed prism, which must should be able to be constructed from both P1::GetterError and P2::GetterError through Into::into.
• A: The target type of the composed prism.
• F2: The type of the fallible iso to compose with.

Parameters

• other: The second Fallible Iso to compose with.

Returns

A new PartialGetterImpl that represents the composition of self and other.

Note

This method uses Into::into to convert the errors from both prisms into the common error type E. If you need custom error mapping, consider using compose_with_fallible_iso_with_mappers.

pub fn compose_with_fallible_iso_with_mappers<E, A, FI2: FallibleIso<I, A>>( self, other: FallibleIsoImpl<I, A, FI2>, getter_error_mapper_1: fn(PG1::GetterError) -> E, getter_error_mapper_2: fn(FI2::GetterError) -> E, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A>>

Composes this PartialGetterImpl<S,I> with a FallibleIso<I,A>, resulting in a new PartialGetterImpl<S, A> that focuses through both optics sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If either prism fails to match, the composition will fail.

Type Parameters

• E: The common error type for the composed prism.
• A: The target type of the composed prism.
• FI2: The type of the fallible iso to compose with.

Parameters

• other: The fallible iso to compose with.
• error_mapper1: A function to map P1::GetterError into E.
• error_mapper2: A function to map F2::GetterError into E.

Returns

A new PartialGetterImpl that represents the composition of self and other with custom error mapping.

Note

This method is similar to compose_with_fallible_iso, but provides the ability to specify custom functions to map the errors from each prism into a common error type.

pub fn compose_with_iso<A, ISO2: Iso<I, A>>( self, other: IsoImpl<I, A, ISO2>, ) -> PartialGetterImpl<S, A, impl PartialGetter<S, A, GetterError = PG1::GetterError>>

Composes this PartialGetterImpl<S,I> with an Iso<I,A>, resulting in a new PartialGetterImpl<S, A> that focuses through both optics sequentially.

The resulting PartialGetterImpl will attempt to extract a value by first applying self and then other. If the prism fails to match, the composition will fail.

Type Parameters

• A: The target type of the composed prism.
• PG2: The type of the lens to compose with.

Parameters

• other: The iso to compose with.

Returns

A new PartialGetterImpl that represents the composition of self and other

Trait Implementations

impl<S, A, PG: PartialGetter<S, A>> From<PG> for PartialGetterImpl<S, A, PG>

fn from(value: PG) -> Self

Converts to this type from the input type.

impl<S, A, PG: PartialGetter<S, A>> HasGetter<S, A> for PartialGetterImpl<S, A, PG>

type GetterError = <PG as HasGetter<S, A>>::GetterError

The type of error that may occur during retrieval. Use Infallible for infallible optics.

fn try_get(&self, source: &S) -> Result<A, Self::GetterError>

Attempts to retrieve a value of type A from a source of type S.