More emulation

Author: zbynek

user/super/com/google/gwt/emul/java/lang/String.java

@@ -32,6 +32,7 @@
 import java.util.Spliterators;
 import java.util.StringJoiner;
 import java.util.function.Consumer;
+import java.util.function.Function;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 import javaemul.internal.ArrayHelper;
@@ -815,6 +816,20 @@ private int getTrailingWhitespaceLength() {
     return length;
   }
 
+  public String indent(int spaces) {
+    if (spaces  == 0) {
+      return this;
+    }
+    if (spaces > 0) {
+      return " ".repeat(spaces) + this;
+    }
+    int prefixLength = 0;
+    while (prefixLength < length() && charAt(prefixLength) == ' ') {
+      prefixLength++;
+    }
+    return substring(prefixLength);
+  }
+
   private class LinesSpliterator extends Spliterators.AbstractSpliterator<String> {
     private int nextIndex = 0;
     private int rPosition = -1;

user/super/com/google/gwt/emul/java/util/stream/IntStream.java

@@ -17,9 +17,11 @@
 
 import static javaemul.internal.InternalPreconditions.checkState;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.IntSummaryStatistics;
+import java.util.List;
 import java.util.OptionalDouble;
 import java.util.OptionalInt;
 import java.util.PrimitiveIterator;
@@ -61,6 +63,15 @@ default IntStream.Builder add(int t) {
     IntStream build();
   }
 
+  /**
+   * See <a
+   * href="https://docs.oracle.com/en/java/javase/16/docs/api/java.base/java/util/stream/IntStream.IntMapMultiConsumer.html">
+   * the official Java API doc</a> for details.
+   */
+  public interface IntMapMultiConsumer {
+    void accept(int value, IntConsumer ic);
+  }
+
   static Builder builder() {
     return new Builder() {
       private int[] items = new int[0];
@@ -366,5 +377,14 @@ public boolean tryAdvance(IntConsumer action) {
     return StreamSupport.intStream(spliterator, false);
   }
 
+  default IntStream mapMulti(IntMapMultiConsumer mapper) {
+    return flatMap(element -> {
+      List<Integer> buffer = new ArrayList<>();
+      IntConsumer consumer = buffer::add;
+      mapper.accept(element, consumer);
+      return buffer.stream().mapToInt(n -> n);
+    });
+  }
+
   int[] toArray();
 }

user/super/com/google/gwt/emul/java/util/stream/Stream.java

@@ -17,8 +17,10 @@
 
 import static javaemul.internal.InternalPreconditions.checkState;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.Comparator;
 import java.util.Optional;
 import java.util.Spliterator;
@@ -28,8 +30,11 @@
 import java.util.function.BiFunction;
 import java.util.function.BinaryOperator;
 import java.util.function.Consumer;
+import java.util.function.DoubleConsumer;
 import java.util.function.Function;
+import java.util.function.IntConsumer;
 import java.util.function.IntFunction;
+import java.util.function.LongConsumer;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 import java.util.function.ToDoubleFunction;
@@ -327,6 +332,41 @@ public boolean tryAdvance(Consumer<? super T> action) {
     return StreamSupport.stream(spliterator, false);
   }
 
+  default public <R> Stream<R> mapMulti(BiConsumer<T, Consumer<? super R>> mapper) {
+    return flatMap(element -> {
+      List<R> buffer = new ArrayList<>();
+      mapper.accept(element, buffer::add);
+      return buffer.stream();
+    });
+  }
+
+  default DoubleStream mapMultiToDouble(BiConsumer<? super T, ? super DoubleConsumer> mapper) {
+    return flatMapToDouble(element -> {
+      List<Double> buffer = new ArrayList<>();
+      DoubleConsumer consumer = buffer::add;
+      mapper.accept(element, consumer);
+      return buffer.stream().mapToDouble(n -> n);
+    });
+  }
+
+  default IntStream mapMultiToInt(BiConsumer<? super T, ? super IntConsumer> mapper) {
+    return flatMapToInt(element -> {
+      List<Integer> buffer = new ArrayList<>();
+      IntConsumer consumer = buffer::add;
+      mapper.accept(element, consumer);
+      return buffer.stream().mapToInt(n -> n);
+    });
+  }
+
+  default LongStream mapMultiToLong(BiConsumer<? super T, ? super LongConsumer> mapper) {
+    return flatMapToLong(element -> {
+      List<Long> buffer = new ArrayList<>();
+      LongConsumer consumer = buffer::add;
+      mapper.accept(element, consumer);
+      return buffer.stream().mapToLong(n -> n);
+    });
+  }
+
   Object[] toArray();
 
   <A> A[] toArray(IntFunction<A[]> generator);

user/test/com/google/gwt/emultest/EmulSuite.gwt.xml

@@ -20,6 +20,7 @@
   <source path='java9' />
   <source path='java10' />
   <source path='java11' />
+  <source path='java12' />
 
   <define-configuration-property name="someConfigurationProperty" is-multi-valued='false'/>
   <set-configuration-property name="someConfigurationProperty" value="conf"/>

user/test/com/google/gwt/emultest/java12/util/stream/CollectorsTest.java

@@ -19,9 +19,6 @@
 import com.google.gwt.emultest.java.util.EmulTestBase;
 import com.google.gwt.junit.JUnitShell;
 
-import java.util.Arrays;
-import java.util.stream.Collectors;
-
 /**
  * Tests for java.lang.String Java 12 API emulation.
  */