fj.data.optic.PLens Maven / Gradle / Ivy
package fj.data.optic;
import fj.F;
import fj.Function;
import fj.Monoid;
import fj.P1;
import fj.Semigroup;
import fj.control.Trampoline;
import fj.control.parallel.Promise;
import fj.data.Either;
import fj.data.IO;
import fj.data.IOFunctions;
import fj.data.List;
import fj.data.Option;
import fj.data.Stream;
import fj.data.Validation;
import fj.data.vector.V2;
/**
* A {@link PLens} can be seen as a pair of functions:
* - {@code get: S => A} i.e. from an {@code S}, we can extract an {@code A}
* - {@code set: (B, S) => T} i.e. if we replace an {@code A} by a {@code B} in an {@code S}, we obtain a {@code T}
*
*
* A {@link PLens} could also be defined as a weaker {@link PIso} where set requires an additional parameter than reverseGet.
*
* {@link PLens} stands for Polymorphic Lens as it set and modify methods change a type {@code A} to {@code B} and {@code S} to {@code T}. {@link Lens}
* is a {@link PLens} restricted to monomoprhic updates.
*
* A {@link PLens} is also a valid {@link Getter}, {@link Fold}, {@link POptional}, {@link PTraversal} and {@link PSetter}
*
* Typically a {@link PLens} or {@link Lens} can be defined between a Product (e.g. case class, tuple, HList) and one of it is
* component.
*
* @param the source of a {@link PLens}
* @param the modified source of a {@link PLens}
* @param the target of a {@link PLens}
* @param the modified target of a {@link PLens}
*/
public abstract class PLens {
PLens() {
super();
}
/** get the target of a {@link PLens} */
public abstract A get(S s);
/** set polymorphically the target of a {@link PLens} using a function */
public abstract F set(B b);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyFunctionF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyEitherF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyIOF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyTrampolineF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyPromiseF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyListF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyOptionF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyStreamF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyP1F(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyValidationF(F> f);
/**
* modify polymorphically the target of a {@link PLens} with an Applicative function
*/
public abstract F> modifyV2F(F> f);
/** modify polymorphically the target of a {@link PLens} using a function */
public abstract F modify(final F f);
/** join two {@link PLens} with the same target */
public final PLens, Either, A, B> sum(final PLens other) {
return pLens(
e -> e.either(this::get, other::get),
b -> e -> e.bimap(PLens.this.set(b), other.set(b)));
}
/***********************************************************/
/** Compose methods between a {@link PLens} and another Optics */
/***********************************************************/
/** compose a {@link PLens} with a {@link Fold} */
public final Fold composeFold(final Fold other) {
return asFold().composeFold(other);
}
/** compose a {@link PLens} with a {@link Getter} */
public final Getter composeGetter(final Getter other) {
return asGetter().composeGetter(other);
}
/**
* compose a {@link PLens} with a {@link PSetter}
*/
public final PSetter composeSetter(final PSetter other) {
return asSetter().composeSetter(other);
}
/**
* compose a {@link PLens} with a {@link PTraversal}
*/
public final PTraversal composeTraversal(final PTraversal other) {
return asTraversal().composeTraversal(other);
}
/** compose a {@link PLens} with an {@link POptional} */
public final POptional composeOptional(final POptional other) {
return asOptional().composeOptional(other);
}
/** compose a {@link PLens} with a {@link PPrism} */
public final POptional composePrism(final PPrism other) {
return asOptional().composeOptional(other.asOptional());
}
/** compose a {@link PLens} with a {@link PLens} */
public final PLens composeLens(final PLens other) {
final PLens self = this;
return new PLens() {
@Override
public C get(final S s) {
return other.get(self.get(s));
}
@Override
public F set(final D d) {
return self.modify(other.set(d));
}
@Override
public F> modifyFunctionF(final F> f) {
return self.modifyFunctionF(other.modifyFunctionF(f));
}
@Override
public F> modifyEitherF(final F> f) {
return self.modifyEitherF(other.modifyEitherF(f));
}
@Override
public F> modifyIOF(final F> f) {
return self.modifyIOF(other.modifyIOF(f));
}
@Override
public F> modifyTrampolineF(final F> f) {
return self.modifyTrampolineF(other.modifyTrampolineF(f));
}
@Override
public F> modifyPromiseF(final F> f) {
return self.modifyPromiseF(other.modifyPromiseF(f));
}
@Override
public F> modifyListF(final F> f) {
return self.modifyListF(other.modifyListF(f));
}
@Override
public F> modifyOptionF(final F> f) {
return self.modifyOptionF(other.modifyOptionF(f));
}
@Override
public F> modifyStreamF(final F> f) {
return self.modifyStreamF(other.modifyStreamF(f));
}
@Override
public F> modifyP1F(final F> f) {
return self.modifyP1F(other.modifyP1F(f));
}
@Override
public F> modifyValidationF(final F> f) {
return self.modifyValidationF(other.modifyValidationF(f));
}
@Override
public F> modifyV2F(final F> f) {
return self.modifyV2F(other.modifyV2F(f));
}
@Override
public F modify(final F f) {
return self.modify(other.modify(f));
}
};
}
/** compose a {@link PLens} with an {@link PIso} */
public final PLens composeIso(final PIso other) {
return composeLens(other.asLens());
}
/************************************************************************************************/
/** Transformation methods to view a {@link PLens} as another Optics */
/************************************************************************************************/
/** view a {@link PLens} as a {@link Fold} */
public final Fold asFold() {
return new Fold() {
@Override
public F foldMap(final Monoid m, final F f) {
return s -> f.f(get(s));
}
};
}
/** view a {@link PLens} as a {@link Getter} */
public final Getter asGetter() {
return new Getter() {
@Override
public A get(final S s) {
return PLens.this.get(s);
}
};
}
/** view a {@link PLens} as a {@link PSetter} */
public PSetter asSetter() {
return new PSetter() {
@Override
public F modify(final F f) {
return PLens.this.modify(f);
}
@Override
public F set(final B b) {
return PLens.this.set(b);
}
};
}
/** view a {@link PLens} as a {@link PTraversal} */
public PTraversal asTraversal() {
final PLens self = this;
return new PTraversal() {
@Override
public F> modifyFunctionF(final F> f) {
return self.modifyFunctionF(f);
}
@Override
public F> modifyEitherF(final F> f) {
return self.modifyEitherF(f);
}
@Override
public F> modifyIOF(final F> f) {
return self.modifyIOF(f);
}
@Override
public F> modifyTrampolineF(final F> f) {
return self.modifyTrampolineF(f);
}
@Override
public F> modifyPromiseF(final F> f) {
return self.modifyPromiseF(f);
}
@Override
public F> modifyListF(final F> f) {
return self.modifyListF(f);
}
@Override
public F> modifyOptionF(final F> f) {
return self.modifyOptionF(f);
}
@Override
public F> modifyStreamF(final F> f) {
return self.modifyStreamF(f);
}
@Override
public F> modifyP1F(final F> f) {
return self.modifyP1F(f);
}
@Override
public F> modifyValidationF(Semigroup s, final F> f) {
return self.modifyValidationF(f);
}
@Override
public F> modifyV2F(final F> f) {
return self.modifyV2F(f);
}
@Override
public F foldMap(final Monoid monoid, final F f) {
return s -> f.f(get(s));
}
};
}
/** view a {@link PLens} as an {@link POptional} */
public POptional asOptional() {
final PLens self = this;
return new POptional() {
@Override
public Either getOrModify(final S s) {
return Either.right(self.get(s));
}
@Override
public F set(final B b) {
return self.set(b);
}
@Override
public Option getOption(final S s) {
return Option.some(self.get(s));
}
@Override
public F> modifyFunctionF(final F> f) {
return self.modifyFunctionF(f);
}
@Override
public F> modifyEitherF(final F> f) {
return self.modifyEitherF(f);
}
@Override
public F> modifyIOF(final F> f) {
return self.modifyIOF(f);
}
@Override
public F> modifyTrampolineF(final F> f) {
return self.modifyTrampolineF(f);
}
@Override
public F> modifyPromiseF(final F> f) {
return self.modifyPromiseF(f);
}
@Override
public F> modifyListF(final F> f) {
return self.modifyListF(f);
}
@Override
public F> modifyOptionF(final F> f) {
return self.modifyOptionF(f);
}
@Override
public F> modifyStreamF(final F> f) {
return self.modifyStreamF(f);
}
@Override
public F> modifyP1F(final F> f) {
return self.modifyP1F(f);
}
@Override
public F> modifyValidationF(final F> f) {
return self.modifyValidationF(f);
}
@Override
public F> modifyV2F(final F> f) {
return self.modifyV2F(f);
}
@Override
public F modify(final F f) {
return self.modify(f);
}
};
}
public static PLens pId() {
return PIso. pId().asLens();
}
/**
* create a {@link PLens} using a pair of functions: one to get the target, one to set the target.
*/
public static PLens pLens(final F get, final F> set) {
return new PLens() {
@Override
public A get(final S s) {
return get.f(s);
}
@Override
public F set(final B b) {
return set.f(b);
}
@Override
public F> modifyFunctionF(final F> f) {
return s -> Function.compose(b -> set.f(b).f(s), f.f(get.f(s)));
}
@Override
public F> modifyEitherF(final F> f) {
return s -> f.f(get.f(s)).right().map(a -> set.f(a).f(s));
}
@Override
public F> modifyIOF(final F> f) {
return s -> IOFunctions.map(f.f(get.f(s)), a -> set.f(a).f(s));
}
@Override
public F> modifyTrampolineF(final F> f) {
return s -> f.f(get.f(s)).map(a -> set.f(a).f(s));
}
@Override
public F> modifyPromiseF(final F> f) {
return s -> f.f(get.f(s)).fmap(a -> set.f(a).f(s));
}
@Override
public F> modifyListF(final F> f) {
return s -> f.f(get.f(s)).map(a -> set.f(a).f(s));
}
@Override
public F> modifyOptionF(final F> f) {
return s -> f.f(get.f(s)).map(a -> set.f(a).f(s));
}
@Override
public F> modifyStreamF(final F> f) {
return s -> f.f(get.f(s)).map(a -> set.f(a).f(s));
}
@Override
public F> modifyP1F(final F> f) {
return s -> f.f(get.f(s)).map(a -> set.f(a).f(s));
}
@Override
public F> modifyValidationF(final F> f) {
return s -> f.f(get.f(s)).map(a -> set.f(a).f(s));
}
@Override
public F> modifyV2F(final F> f) {
return s -> f.f(get.f(s)).map(a -> set.f(a).f(s));
}
@Override
public F modify(final F f) {
return s -> set.f(f.f(get.f(s))).f(s);
}
};
}
}
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