Hi,
Please review this specification clarification for the stream returning methods
on CharSequence and BitStream. Those methods specify that the stream is
late-binding for mutable sequences.
I think those are the only relevant cases, please tell me if there are more!
When looking at AbstractStringBuilder i found a bug:
@Override
public IntStream chars() {
byte[] val = this.value; int count = this.count; byte coder = this.coder;
checkOffset(count, val.length >> coder);
// Reuse String-based spliterator. This requires a supplier to
// capture the value and count when the terminal operation is executed
return StreamSupport.intStream(
() -> coder == LATIN1 ? new StringLatin1.CharsSpliterator(val, 0,
count, 0)
: new StringUTF16.CharsSpliterator(val, 0,
count, 0),
Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED,
false);
}
The returned stream is not late-binding since it captures state as local
variables. That was an oversight missed in review when the compact string
changes were pushed. I will file an issue and fix it (including tests).
Paul.
diff -r a11577c64a1d src/java.base/share/classes/java/lang/CharSequence.java
--- a/src/java.base/share/classes/java/lang/CharSequence.java Mon Nov 21
10:50:01 2016 -0800
+++ b/src/java.base/share/classes/java/lang/CharSequence.java Mon Nov 21
12:17:08 2016 -0800
@@ -121,8 +121,11 @@
* 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.
+ * <p>The stream binds to this sequence when the terminal stream operation
+ * commences. If the sequence is modified during that operation then the
+ * result is undefined. (Specifically, for mutable sequences the
+ * spliterator for the stream is
+ * <a href="../Spliterator.html#binding"><em>late-binding</em></a>.)
*
* @return an IntStream of char values from this sequence
* @since 1.8
@@ -168,8 +171,11 @@
* 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.
+ * <p>The stream binds to this sequence when the terminal stream operation
+ * commences. If the sequence is modified during that operation then the
+ * result is undefined. (Specifically, for mutable sequences the
+ * spliterator for the stream is
+ * <a href="../Spliterator.html#binding"><em>late-binding</em></a>.)
*
* @return an IntStream of Unicode code points from this sequence
* @since 1.8
diff -r a11577c64a1d src/java.base/share/classes/java/util/BitSet.java
--- a/src/java.base/share/classes/java/util/BitSet.java Mon Nov 21 10:50:01
2016 -0800
+++ b/src/java.base/share/classes/java/util/BitSet.java Mon Nov 21 12:17:08
2016 -0800
@@ -1210,9 +1210,10 @@
* is the number of bits in the set state, equal to the value
* returned by the {@link #cardinality()} method.
*
- * <p>The bit set must remain constant during the execution of the
- * terminal stream operation. Otherwise, the result of the terminal
- * stream operation is undefined.
+ * <p>The stream binds to this bit set when the terminal stream operation
+ * commences. If the bit set is modified during that operation then the
+ * result is undefined. (Specifically, the spliterator for the stream is
+ * <a href="../Spliterator.html#binding"><em>late-binding</em></a>.)
*
* @return a stream of integers representing set indices
* @since 1.8
