org.jooq.lambda.Partition Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jool-java-8 Show documentation

jOOλ is part of the jOOQ series (along with jOOQ, jOOX, jOOR, jOOU) providing some useful extensions to Java 8 lambdas.

There is a newer version: 0.9.15

/**
 * Copyright (c), Data Geekery GmbH, [email protected]
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jooq.lambda;

import java.util.*;
import java.util.function.BooleanSupplier;
import java.util.function.Supplier;

import org.jooq.lambda.tuple.Tuple2;

/**
 * @author Lukas Eder
 */
class Partition {

    final List> list;
    final Map   cache;

    Partition(Collection> list) {
        this.list = list instanceof ArrayList ? (List>) list : new ArrayList<>(list);
        this.cache = new HashMap<>();
    }

     R cacheIf(boolean condition, Object key, Supplier value) {
        return cacheIf(() -> condition, () -> key, value);
    }

     R cacheIf(boolean condition, Supplier key, Supplier value) {
        if (condition)
            return cache(key, value);
        else
            return value.get();
    }

     R cacheIf(BooleanSupplier condition, Object key, Supplier value) {
        return cacheIf(condition, () -> key, value);
    }

     R cacheIf(BooleanSupplier condition, Supplier key, Supplier value) {
        if (condition.getAsBoolean())
            return cache(key, value);
        else
            return value.get();
    }

    @SuppressWarnings("unchecked")
     R cache(Object key, Supplier value) {
        return cache(() -> key, value);
    }

    @SuppressWarnings("unchecked")
     R cache(Supplier key, Supplier value) {
        return (R) cache.computeIfAbsent(key.get(), k -> value.get());
    }
}