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The module for FunctionalJ Core.
There is a newer version: 1.0.17
// ============================================================================
// Copyright (c) 2017-2019 Nawapunth Manusitthipol (NawaMan - http://nawaman.net).
// ----------------------------------------------------------------------------
// MIT License
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
// ============================================================================
package functionalj.lens.lenses;

import static functionalj.lens.core.LensUtils.createLensSpecParameterized;

import java.util.function.Function;

import functionalj.lens.core.AccessParameterized;
import functionalj.lens.core.LensSpec;
import functionalj.lens.core.LensSpecParameterized;
import functionalj.lens.core.WriteLens;
import lombok.val;
import nullablej.nullable.Nullable;

@SuppressWarnings("javadoc")
@FunctionalInterface
public interface NullableLens>
                    extends 
                        ObjectLens>,
                        NullableAccess {
    
    public static >
        NullableLens of(
            LensSpec> nullableLensSpec,
            Function, SUBLENS> subCreator) {
        val read  = nullableLensSpec.getRead();
        val write = nullableLensSpec.getWrite();
        val spec  = createLensSpecParameterized(read, write, subCreator);
        val nullableLens = (NullableLens)()->spec;
        return nullableLens;
    }
    
    
    public LensSpecParameterized, TYPE, SUBLENS> lensSpecWithSub();

    @Override
    default AccessParameterized, TYPE, SUBLENS> accessWithSub() {
        return lensSpecWithSub();
    }
    
    @Override
    public default SUBLENS createSubAccess(Function, TYPE> accessToSub) {
        return lensSpecWithSub().createSubAccess(accessToSub);
    }
    
    @Override
    public default LensSpec> lensSpec() {
        return lensSpecWithSub().getSpec();
    }
    
    @Override
    public default Nullable applyUnsafe(HOST host) throws Exception {
        return lensSpec().getRead().apply(host);
    }
    
    public default SUBLENS get() {
        WriteLens write = (HOST host, TYPE newValue)->{
            return lensSpec().getWrite().apply(host, Nullable.of(newValue));
        };
        LensSpec subSpec = LensSpec.of(lensSpec().getRead().andThen(Nullable::get), write);
        return lensSpecWithSub().createSubLens(subSpec);
    }
    
}