RFR 8169808 Stream returning methods should specify if they are late binding

[Tagir Valeev]

Hello!


> 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>.)

As this an interface method with default implementation, I think, it should be
clear whether this states a method contract for all implementors or an
implementation detail of
the default implementation. Here it's not in the @implNote section, so
I assume that the new statement
tightens the specification for all possible implementors (probably
making valid Java-8 code invalid in Java-9
if somebody reimplemented chars() for custom CharSequence in
non-late-binding manner).
Is this spec change intended?

With best regards,
Tagir Valeev.