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java实现 流
1 parent 42e8101 commit 154bf42

11 files changed

Lines changed: 165 additions & 49 deletions

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‎.gitignore‎

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# Created by .ignore support plugin (hsz.mobi)
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### Example user template template
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### Example user template
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# IntelliJ project files
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.idea
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*.iml
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out
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gen

‎src/java/Test.java‎

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This file was deleted.

‎src/js/stream-opt.js‎

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// stream map 操作
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function map_stream(mapper,stream){
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function map_stream(map,stream){
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if(is_empty_stream(stream)){
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return empty_stream();
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}
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return cons_stream(
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mapper(head(stream)),
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map(head(stream)),
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function(){
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return map_stream(mapper,tail(stream));
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return map_stream(map,tail(stream));
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}
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);
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}
@@ -75,9 +75,9 @@ function flatten_stream(stream_in_stream){
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}
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// stream flattenMap
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function flatten_map_stream(mapper,stream_in_stream){
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function flatten_map_stream(map,stream_in_stream){
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return flatten_stream(
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map_stream(mapper,stream_in_stream)
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map_stream(map,stream_in_stream)
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);
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}
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‎src/main/java/functional/Accumulate.java‎

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*/
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public interface Accumulate <T>{
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T accumulate(T t1, T t2);
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T apply(T t1, T t2);
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}

‎src/main/java/functional/ForEach.java‎

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@FunctionalInterface
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public interface ForEach <T>{
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void forEach(T item);
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void apply(T item);
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}

src/main/java/functional/Mapper.java renamed to src/main/java/functional/Map.java

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* @Author xiongyx
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* on 2019/3/5.
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*
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* map 映射操作
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* apply 映射操作
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*/
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@FunctionalInterface
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public interface Mapper <R,T>{
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public interface Map<R,T>{
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R map(T item);
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R apply(T item);
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}

‎src/main/java/functional/NextItem.java‎

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* on 2019/3/5.
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*/
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@FunctionalInterface
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public interface NextItem {
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public interface NextItem<T> {
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Stream next();
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Stream<T> apply();
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}

‎src/main/java/stream/Stream.java‎

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@@ -1,44 +1,119 @@
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package stream;
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import functional.ForEach;
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import functional.Mapper;
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import functional.Map;
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import functional.NextItem;
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import functional.Predicate;
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import java.util.List;
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/**
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* @Author xiongyx
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* on 2019/3/5.
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*/
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public class Stream <T>{
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public class Stream <T> implements StreamInterface<T>{
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//=====================================成员属性===============================
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private T head;
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private NextItem nextItem;
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private Stream<T> tail;
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private boolean isEnd;
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/**
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* 是否被求值过
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* */
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private boolean evaled;
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private NextItem<T> eval;
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public T getHead() {
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return head;
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}
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public void setHead(T head) {
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this.head = head;
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}
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public Stream<T> getTail() {
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return tail;
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}
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public void setTail(Stream<T> tail) {
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this.tail = tail;
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}
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public NextItem<T> getEval() {
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return eval;
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}
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public void setEval(NextItem<T> eval) {
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this.eval = eval;
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}
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//====================================构造函数===============================
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public Stream() {
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}
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private Stream(List<T> list){
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public Stream(T head, Stream<T> tail) {
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this.head = head;
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this.tail = tail;
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}
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public Stream(NextItem<T> eval) {
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this.eval = eval;
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}
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//=====================================公共接口=================================
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public <R> Stream<R> map(Mapper<R,T> mapper){
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public Stream(boolean isEnd) {
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this.isEnd = isEnd;
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}
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return new Stream<>();
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//=====================================公共接口=================================
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@Override
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public <R> Stream<R> map(Map<R,T> mapper){
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return map(mapper,this);
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}
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@Override
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public Stream<T> filter(Predicate<T> predicate){
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return new Stream<>();
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}
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@Override
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public void forEach(ForEach<T> forEach){
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}
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//=====================================私有方法=====================================
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private <R> Stream<R> map(Map<R,T> mapper,Stream<T> stream){
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if(isEmptyStream(stream)){
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return StreamInterface.makeEmptyStream();
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}
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R head = mapper.apply(stream.head);
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Stream tail = new Stream<>(
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()-> map(mapper,stream.force()
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));
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Stream newStream = new Stream(
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head,
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tail
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);
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return newStream;
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}
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private void delay(NextItem<T> nextItem){
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}
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private Stream force(){
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return this.tail.eval.apply();
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}
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private static boolean isEmptyStream(Stream stream){
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return stream.isEnd;
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}
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}

‎src/main/java/stream/StreamGenerator.java‎

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package stream;
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/**
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* @Author xiongyx
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* on 2019/3/5.
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*/
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public class StreamGenerator {
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public static Stream<Integer> getIntegerStream(int n){
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if(n < 0){
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return StreamInterface.makeEmptyStream();
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}
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Stream intStream = new Stream<>(
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n,
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new Stream(
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()->getIntegerStream(n-1)
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)
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);
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return intStream;
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}
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}

‎src/main/java/stream/StreamInterface.java‎

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package stream;
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import functional.ForEach;
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import functional.Map;
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import functional.Predicate;
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/**
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* @Author xiongyx
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* on 2019/3/5.
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*/
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public interface StreamInterface<T> {
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<R> Stream<R> map(Map<R,T> mapper);
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Stream<T> filter(Predicate<T> predicate);
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void forEach(ForEach<T> forEach);
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static <T> Stream<T> makeEmptyStream(){
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return new Stream<>(true);
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}
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}

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