RFR: 8343110: Add getChars(int, int, char[], int) to CharSequence and CharBuffer

[Chen Liang]

On Sat, 26 Oct 2024 15:48:11 GMT, Markus KARG <duke at openjdk.org> wrote:

> This Pull Request proposes an implementation for [JDK-8343110](https://bugs.openjdk.org/browse/JDK-8343110): Adding the new method `public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)` to the `CharSequence` interface, providing a **bulk-read** facility including a default implementation iterating over `charAt(int)`.
> 
> In addition, this Pull Request proposes to replace the implementation of `Reader.of(CharSequence).read(char[] cbuf, int off, int len)` to invoke `CharSequence.getChars(next, next + n, cbuf, off)` instead of utilizing pattern matching for switch. Also, this PR proposes to implement `CharBuffer.getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)` as an alias for `CharBuffer.get(srcBegin, dst, dstBegin, srcEnd - srcBegin)`.
> 
> To ensure quality...
> * ...the method signature and JavaDocs are adapted from `AbstractStringBuilder.getChars(...)`.
> * ...this PR relies upon the existing tests for `Reader.of(CharSequence)`, as these provide sufficient coverage of all changes introduced by this PR.

Sorry for belated mail response, but I think we should design the API to not take source start/end. I think JIT can escape analysis the new String in practice.

Hi Markus, I recommend to continue the discussion on the mailing list instead of on GitHub. Note that GitHub pull requests are only forwarded to the mailing list when it's ready for review, and this proposal is way too early. (And the CSR is too early, too: we should agree on an API surface, such as exception contracts, first)

Sorry that no one has responded to you yet, but many engineers are busy with other areas, such as pushing the JEPs (as you see, we have a huge number of candidate/submitted JEPs right now, and JDK 24 RDP1 is just 6 weeks away). They are monitoring your core-libs thread, stay assured!

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PR Comment: https://git.openjdk.org/jdk/pull/21730#issuecomment-2439641840
PR Comment: https://git.openjdk.org/jdk/pull/21730#issuecomment-2439740522