com.gs.collections.api.LazyIterable Maven / Gradle / Ivy

Go to download
/*
 * Copyright 2015 Goldman Sachs.
 *
 * 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 com.gs.collections.api;

import java.util.Collection;

import com.gs.collections.api.block.function.Function;
import com.gs.collections.api.block.function.Function2;
import com.gs.collections.api.block.function.primitive.BooleanFunction;
import com.gs.collections.api.block.function.primitive.ByteFunction;
import com.gs.collections.api.block.function.primitive.CharFunction;
import com.gs.collections.api.block.function.primitive.DoubleFunction;
import com.gs.collections.api.block.function.primitive.FloatFunction;
import com.gs.collections.api.block.function.primitive.IntFunction;
import com.gs.collections.api.block.function.primitive.LongFunction;
import com.gs.collections.api.block.function.primitive.ShortFunction;
import com.gs.collections.api.block.predicate.Predicate;
import com.gs.collections.api.block.predicate.Predicate2;
import com.gs.collections.api.block.procedure.Procedure;
import com.gs.collections.api.tuple.Pair;

/**
 * A LazyIterable is RichIterable which will defer evaluation for certain methods like select, reject, collect, etc.
 * Any methods that do not return a LazyIterable when called will cause evaluation to be forced.
 *
 * @since 1.0
 */
public interface LazyIterable
        extends RichIterable
{
    /**
     * @inheritDoc
     */
    T getFirst();

    /**
     * Creates a deferred iterable for selecting elements from the current iterable.
     */
    LazyIterable select(Predicate predicate);

     LazyIterable selectWith(Predicate2 predicate, P parameter);

     LazyIterable selectInstancesOf(Class clazz);

    /**
     * Creates a deferred iterable for rejecting elements from the current iterable.
     */
    LazyIterable reject(Predicate predicate);

     LazyIterable rejectWith(Predicate2 predicate, P parameter);

    /**
     * Creates a deferred iterable for collecting elements from the current iterable.
     */
     LazyIterable collect(Function function);

     LazyIterable collectWith(Function2 function, P parameter);

    /**
     * Creates a deferred iterable for selecting and collecting elements from the current iterable.
     */
     LazyIterable collectIf(Predicate predicate, Function function);

    /**
     * Creates a deferred take iterable for the current iterable using the specified count as the limit.
     */
    LazyIterable take(int count);

    /**
     * Creates a deferred drop iterable for the current iterable using the specified count as the limit.
     */
    LazyIterable drop(int count);

    /**
     * Creates a deferred distinct iterable to get distinct elements from the current iterable.
     *
     * @since 5.0
     */
    LazyIterable distinct();

    /**
     * Creates a deferred flattening iterable for the current iterable.
     */
     LazyIterable flatCollect(Function> function);

    /**
     * Creates a deferred iterable that will join this iterable with the specified iterable.
     */
    LazyIterable concatenate(Iterable iterable);

    /**
     * Creates a deferred zip iterable.
     */
     LazyIterable> zip(Iterable that);

    /**
     * Creates a deferred zipWithIndex iterable.
     */
    LazyIterable> zipWithIndex();

    /**
     * Creates a deferred chunking iterable.
     */
    LazyIterable> chunk(int size);

    /**
     * Creates a deferred tap iterable.
     */
    LazyIterable tap(Procedure procedure);

    /**
     * Iterates over this iterable adding all elements into the target collection.
     */
    > R into(R target);

    /**
     * Returns a lazy BooleanIterable which will transform the underlying iterable data to boolean values based on the booleanFunction.
     */
    LazyBooleanIterable collectBoolean(BooleanFunction booleanFunction);

    /**
     * Returns a lazy ByteIterable which will transform the underlying iterable data to byte values based on the byteFunction.
     */
    LazyByteIterable collectByte(ByteFunction byteFunction);

    /**
     * Returns a lazy CharIterable which will transform the underlying iterable data to char values based on the charFunction.
     */
    LazyCharIterable collectChar(CharFunction charFunction);

    /**
     * Returns a lazy DoubleIterable which will transform the underlying iterable data to double values based on the doubleFunction.
     */
    LazyDoubleIterable collectDouble(DoubleFunction doubleFunction);

    /**
     * Returns a lazy FloatIterable which will transform the underlying iterable data to float values based on the floatFunction.
     */
    LazyFloatIterable collectFloat(FloatFunction floatFunction);

    /**
     * Returns a lazy IntIterable which will transform the underlying iterable data to int values based on the intFunction.
     */
    LazyIntIterable collectInt(IntFunction intFunction);

    /**
     * Returns a lazy LongIterable which will transform the underlying iterable data to long values based on the longFunction.
     */
    LazyLongIterable collectLong(LongFunction longFunction);

    /**
     * Returns a lazy ShortIterable which will transform the underlying iterable data to short values based on the shortFunction.
     */
    LazyShortIterable collectShort(ShortFunction shortFunction);
}