Hi, I'm wondering, that StringJoiner has some logic for pre/suffix, but nothing to loop the elements themselves :-( To me, StringJoiner is a useless complicated box around StringBuilder, and imagine, someone needs thread-safety. It also slows down performance, as it needs additional instances and additional class to be loaded (critical at VM startup). Instead please add to StringBuilder and StringBuffer: append(CharSequence... elements); append(char delimiter, CharSequence... elements); append(char delimiter, Iterable<? extends CharSequence> elements); cut(int len); // removes len chars at the end of the sequence optional: append(CharSequence delimiter, CharSequence... elements); append(CharSequence delimiter, Iterable<? extends CharSequence> elements); For performance reasons, append should always append the trailing delimeter, which could be cut at the end. It's questionable, if class string needs a static (=no relation to an existing string in contrast to non-static split()) join method, as it seduces to "[" + String.join(...) + "]" which needs some effort from javac side to optimize to a single StringBuilder task. IMO we better had StringBuilder.join(...), so javac could easily optimize to: new StringBuilder().append('[').append(',', someStrings).cut(1).append(']').toString() -Ulf Am 18.04.2013 00:07, schrieb Martin Buchholz:
I'm still wondering about whether a joiner utility should support a prefix and suffix. The obvious uses for this are collection class toString methods, but we already know that we can and should implement those with a single precise char[] construction, so should not use StringJoiner, or at least not this StringJoiner implementation. And if we're just talking about pure convenience, it's hard to beat
"[" + String.join(...) + "]"
On Wed, Apr 17, 2013 at 2:49 PM, Jim Gish <jim.gish@oracle.com> wrote:
Here's an update: http://cr.openjdk.java.net/~** jgish/Bugs-5015163-7172553/<http://cr.openjdk.java.net/~jgish/Bugs-5015163-7172553/><; http://cr.openjdk.java.net/%**7Ejgish/Bugs-5015163-7172553/<http://cr.openjdk.java.net/%7Ejgish/Bugs-5015163-7172553/> Jim
On 04/17/2013 03:15 PM, Mike Duigou wrote:
String::
line 1253: This should use {@code } rather than <code></code>. I think regular spaces are OK as well. seems inappropriate.
lines 2425/2467: elements may not be null either.
I can tell you (or maybe it's just me) are itching to change :
for (CharSequence cs: elements) { 2477 joiner.add(cs); 2478 }
to:
elements.forEach(joiner::add);
StringJoiner::
- <blockquote> isn't needed around <pre> as it's already a <div> you probably mean to do
<pre> {@code ... }</pre>
for code samples.
- It would be nice if the empty output generation in three arg constructor could be suppressed unless needed. Perhaps a special (not null please!) sentinel value?
- Four arg constructor doesn't include emptyOutput in @throws NPE
On Apr 11 2013, at 15:33 , Jim Gish wrote:
Please review http://cr.openjdk.java.net/~**jgish/Bugs-5015163-7175206-*
*7172553/<http://cr.openjdk.java.net/~jgish/Bugs-5015163-7175206-7172553/><; http://cr.openjdk.java.net/%**7Ejgish/Bugs-5015163-7175206-**7172553/<http://cr.openjdk.java.net/%7Ejgish/Bugs-5015163-7175206-7172553/> These are changes that we made in lambda that we're now bringing into JDK8.
I've made a couple of additions - making StringJoiner final and adding a couple of constructors to set the emptyOutput chars.
Thanks, Jim
-- Jim Gish | Consulting Member of Technical Staff | +1.781.442.0304 Oracle Java Platform Group | Core Libraries Team 35 Network Drive Burlington, MA 01803 jim.gish@oracle.com
-- Jim Gish | Consulting Member of Technical Staff | +1.781.442.0304 Oracle Java Platform Group | Core Libraries Team 35 Network Drive Burlington, MA 01803 jim.gish@oracle.com