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The module for FunctionalJ Core.
There is a newer version: 1.0.17
// ============================================================================
// Copyright (c) 2017-2021 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.stream;

import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Stream;

import lombok.val;


public interface StreamPlusWithFlatMap {
    
    public StreamPlus streamPlus();
    
    /** FlatMap with the given mapper for only the value that pass the condition. */
    public default StreamPlus flatMapOnly(
            Predicate                        condition, 
            Function> mapper) {
        val streamPlus = streamPlus();
        return streamPlus
                .flatMap(value -> {
                    val isTrue = condition.test(value);
                    val mapped = isTrue
                            ? mapper.apply(value)
                            : StreamPlus.of(value);
                    return mapped;
                });
    }
    
    /** FlatMap with the mapper if the condition is true, otherwise use another elseMapper. */
    public default  StreamPlus flatMapIf(
            Predicate           condition, 
            Function> mapper, 
            Function> elseMapper) {
        val streamPlus = streamPlus();
        return streamPlus
                .flatMap(value -> {
                    val isTrue = condition.test(value);
                    val mapped = isTrue
                            ? mapper.apply(value)
                            : elseMapper.apply(value);
                    return mapped;
                });
    }
    
}