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/*
* esodata - data structures and other things, of varying utility
* Copyright 2022, Ben Culkin
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package bjc.optics;
import java.util.function.Function;
import bjc.data.Either;
/**
* Represents a Prism, which is a type of optic.
*
* TODO: Add better description
*
* @author bjcul
*
* @param <W1> The type of the first whole
* @param <W2> The type of the second whole
* @param <P1> The type of the first part
* @param <P2> The type of the second part
*/
public interface PrismX<W1, W2, P1, P2> extends Optic<W1, W2, P1, P2> {
/**
* Match against this prism.
*
* @param part The part to match
* @return Either the matched value or the prism
*/
Either<P2, W1> match(P1 part);
/**
* Build this prism from a given part.
*
* @param whole The whole to build from
* @return The part that is constructed
*/
P2 build(W2 whole);
/**
* Create a prism from its component parts
*
* @param <W1> The type of the first whole
* @param <W2> The type of the second whole
* @param <P1> The type of the first part
* @param <P2> The type of the second part
*
* @param f The 'match' function for the prism
* @param g The 'build' function for the prism
*
* @return A prism built from the given parts
*/
static <W1, W2, P1, P2> PrismX<W1, W2, P1, P2> of(Function<P1, Either<P2, W1>> f, Function<W2, P2> g) {
return new FunctionalPrismX<>(g, f);
}
}
final class FunctionalPrismX<W1, W2, P1, P2> implements PrismX<W1, W2, P1, P2> {
private final Function<W2, P2> g;
private final Function<P1, Either<P2, W1>> f;
public FunctionalPrismX(Function<W2, P2> g, Function<P1, Either<P2, W1>> f) {
this.g = g;
this.f = f;
}
@Override
public P2 build(W2 whole) {
return g.apply(whole);
}
@Override
public Either<P2, W1> match(P1 part) {
return f.apply(part);
}
}
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