src/share/classes/java/lang/CharSequence.java

rev 7005 : 8012665: CharSequence.chars, CharSequence.codePoints
Reviewed-by:
Contributed-by: smarks

*** 1,7 ****
  /*
!  * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 23,32 ****
--- 23,39 ----
   * questions.
   */
  
  package java.lang;
  
+ import java.util.NoSuchElementException;
+ import java.util.PrimitiveIterator;
+ import java.util.Spliterator;
+ import java.util.Spliterators;
+ import java.util.function.IntConsumer;
+ import java.util.stream.IntStream;
+ import java.util.stream.StreamSupport;
  
  /**
   * A <tt>CharSequence</tt> is a readable sequence of <code>char</code> values. This
   * interface provides uniform, read-only access to many different kinds of
   * <code>char</code> sequences.
*** 106,111 ****
--- 113,209 ----
       *
       * @return  a string consisting of exactly this sequence of characters
       */
      public String toString();
  
+     /**
+      * Returns a stream of {@code int} zero-extending the {@code char} values
+      * from this sequence.  Any char which maps to a <a
+      * href="{@docRoot}/java/lang/Character.html#unicode">surrogate code
+      * point</a> is passed through uninterpreted.
+      *
+      * <p>If the sequence is mutated while the stream is being read, the
+      * result is undefined.
+      *
+      * @return an IntStream of char values from this sequence
+      * @since 1.8
+      */
+     public default IntStream chars() {
+         class CharIterator implements PrimitiveIterator.OfInt {
+             int cur = 0;
+ 
+             public boolean hasNext() {
+                 return cur < length();
+             }
+ 
+             public int nextInt() {
+                 if (hasNext()) {
+                     return charAt(cur++);
+                 } else {
+                     throw new NoSuchElementException();
+                 }
+             }
+ 
+             @Override
+             public void forEachRemaining(IntConsumer block) {
+                 for (; cur < length(); cur++) {
+                     block.accept(charAt(cur));
+                 }
+             }
+         }
+ 
+         return StreamSupport.intStream(() ->
+                 Spliterators.spliterator(
+                         new CharIterator(),
+                         length(),
+                         Spliterator.ORDERED),
+                 Spliterator.SUBSIZED | Spliterator.SIZED | Spliterator.ORDERED);
+     }
+ 
+     /**
+      * Returns a stream of code point values from this sequence.  Any surrogate
+      * pairs encountered in the sequence are combined as if by {@linkplain
+      * Character#toCodePoint Character.toCodePoint} and the result is passed
+      * to the stream. Any other code units, including ordinary BMP characters,
+      * unpaired surrogates, and undefined code units, are zero-extended to
+      * {@code int} values which are then passed to the stream.
+      *
+      * <p>If the sequence is mutated while the stream is being read, the result
+      * is undefined.
+      *
+      * @return an IntStream of Unicode code points from this sequence
+      * @since 1.8
+      */
+     public default IntStream codePoints() {
+         class CodePointIterator implements PrimitiveIterator.OfInt {
+             int cur = 0;
+ 
+             @Override
+             public void forEachRemaining(IntConsumer block) {
+                 while (cur < length()) {
+                     int cp = Character.codePointAt(CharSequence.this, cur);
+                     cur += Character.charCount(cp);
+                     block.accept(cp);
+                 }
+             }
+ 
+             public boolean hasNext() {
+                 return cur < length();
+             }
+ 
+             public int nextInt() {
+                 if (!hasNext()) {
+                     throw new NoSuchElementException();
+                 }
+                 int cp = Character.codePointAt(CharSequence.this, cur);
+                 cur += Character.charCount(cp);
+                 return cp;
+             }
+         }
+ 
+         return StreamSupport.intStream(() ->
+                 Spliterators.spliteratorUnknownSize(
+                         new CodePointIterator(),
+                         Spliterator.ORDERED),
+                 Spliterator.SUBSIZED | Spliterator.SIZED | Spliterator.ORDERED);
+     }
  }