Commit b856c56

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Custom operator example

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+75

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Lines changed: 49 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,49 @@`
	`1`	`+package com.annimon.java8streamexample;`
	`2`	`+`
	`3`	`+import com.annimon.stream.Stream;`
	`4`	`+import com.annimon.stream.function.Function;`
	`5`	`+import java.util.Iterator;`
	`6`	`+`
	`7`	`+public final class CustomOperators {`
	`8`	`+`
	`9`	`+ public static <T> Index<T> index() {`
	`10`	`+ return index(0);`
	`11`	`+ }`
	`12`	`+`
	`13`	`+ public static <T> Index<T> index(int from) {`
	`14`	`+ return new Index<>(from);`
	`15`	`+ }`
	`16`	`+`
	`17`	`+ private static class Index<T> implements Function<Stream<T>, Stream<IntPair<T>>> {`
	`18`	`+`
	`19`	`+ private final int startFrom;`
	`20`	`+`
	`21`	`+ public Index(int startFrom) {`
	`22`	`+ this.startFrom = startFrom;`
	`23`	`+ }`
	`24`	`+`
	`25`	`+ @Override`
	`26`	`+ public Stream<IntPair<T>> apply(Stream<T> stream) {`
	`27`	`+ final Iterator<? extends T> iterator = stream.iterator();`
	`28`	`+ return Stream.of(new Iterator<IntPair<T>>() {`
	`29`	`+`
	`30`	`+ private int index = startFrom;`
	`31`	`+`
	`32`	`+ @Override`
	`33`	`+ public boolean hasNext() {`
	`34`	`+ return iterator.hasNext();`
	`35`	`+ }`
	`36`	`+`
	`37`	`+ @Override`
	`38`	`+ public IntPair<T> next() {`
	`39`	`+ return new IntPair<>(index++, iterator.next());`
	`40`	`+ }`
	`41`	`+`
	`42`	`+ @Override`
	`43`	`+ public void remove() {`
	`44`	`+ throw new UnsupportedOperationException();`
	`45`	`+ }`
	`46`	`+ });`
	`47`	`+ }`
	`48`	`+ }`
	`49`	`+}`

Lines changed: 20 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,20 @@`
	`1`	`+package com.annimon.java8streamexample;`
	`2`	`+`
	`3`	`+public class IntPair<T> {`
	`4`	`+`
	`5`	`+ private final int index;`
	`6`	`+ private final T object;`
	`7`	`+`
	`8`	`+ public IntPair(int index, T object) {`
	`9`	`+ this.index = index;`
	`10`	`+ this.object = object;`
	`11`	`+ }`
	`12`	`+`
	`13`	`+ public int getIndex() {`
	`14`	`+ return index;`
	`15`	`+ }`
	`16`	`+`
	`17`	`+ public T getObject() {`
	`18`	`+ return object;`
	`19`	`+ }`
	`20`	`+}`

Lines changed: 4 additions & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -11,7 +11,6 @@`
`11`	`11`	`import com.annimon.stream.IntStream;`
`12`	`12`	`import com.annimon.stream.RandomCompat;`
`13`	`13`	`import com.annimon.stream.Stream;`
`14`		`-import java.util.Random;`
`15`	`14`
`16`	`15`	`public final class MainActivity extends ActionBarActivity {`
`17`	`16`
`@@ -119,6 +118,10 @@ private void action(String action) {`
`119`	`118`	`.mapToObj(i -> String.format("%d. %s", i+1, mAdapter.getItem(i).getWord()))`
`120`	`119`	`.map(str -> new Word(str, ""));`
`121`	`120`	`break;`
	`121`	`+ case "add index custom op":`
	`122`	`+ stream = stream.custom(CustomOperators.index(1))`
	`123`	`+ .map(p -> new Word(String.format("%d. %s", p.getIndex(), p.getObject()), ""));`
	`124`	`+ break;`
`122`	`125`	`case "skip %N":`
`123`	`126`	`stream = stream.skip(filterValue);`
`124`	`127`	`break;`

Lines changed: 2 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -16,6 +16,7 @@`
`16`	`16`	`<item>Filter N symbols</item>`
`17`	`17`	`<item>Is contains "ok"?</item>`
`18`	`18`	`<item>Add index</item>`
	`19`	`+ <item>Add index with custom operator</item>`
`19`	`20`	`<item>Skip first N rows</item>`
`20`	`21`	`<item>Limit N rows</item>`
`21`	`22`	`<item>Group by first character</item>`
`@@ -32,6 +33,7 @@`
`32`	`33`	`<item>filter %N length</item>`
`33`	`34`	`<item>contains ok</item>`
`34`	`35`	`<item>add index</item>`
	`36`	`+ <item>add index custom op</item>`
`35`	`37`	`<item>skip %N</item>`
`36`	`38`	`<item>limit %N</item>`
`37`	`39`	`<item>group</item>`

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