<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><br></div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From: </b>"Viktor Klang" <viktor.klang@oracle.com><br><b>To: </b>"Remi Forax" <forax@univ-mlv.fr><br><b>Cc: </b>"core-libs-dev" <core-libs-dev@openjdk.java.net>, "Paul Sandoz" <psandoz@openjdk.java.net><br><b>Sent: </b>Wednesday, January 24, 2024 2:45:15 PM<br><b>Subject: </b>Re: Gatherer: spliterator characteristics are not propagated<br></blockquote></div><div><style style="display:none;"> P {margin-top:0;margin-bottom:0;} </style></div><div data-marker="__QUOTED_TEXT__"><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">
<div class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">As a (related) side-note, the ability to implement the interface directly has a significant
benefit to being able to have tighter control on efficiency/performance as well as behavior under composition, here are some examples:
</span><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><a href="https://github.com/openjdk/jdk/blob/master/test/micro/org/openjdk/bench/java/util/stream/ops/ref/BenchmarkGathererImpls.java#L113" id="LPlnk753508" target="_blank">https://github.com/openjdk/jdk/blob/master/test/micro/org/openjdk/bench/java/util/stream/ops/ref/BenchmarkGathererImpls.java#L113</a></span><br data-mce-bogus="1"></div>
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</div></blockquote><div><br></div><div>I've not seen any differences in term of performance:<br data-mce-bogus="1"></div><pre><span style="font-family: lucida console, sans-serif;" data-mce-style="font-family: lucida console, sans-serif;">MapGathererBenchmark.gatherer_map_sum avgt 5 546.058 ± 4.224 us/op</span><br><span style="font-family: lucida console, sans-serif;" data-mce-style="font-family: lucida console, sans-serif;">MapGathererBenchmark.gatherer_mapsublcass_sum avgt 5 546.391 ± 1.508 us/op</span><br data-mce-bogus="1"></pre><div>but yes, being able to override andThen() is important.</div><div><br data-mce-bogus="1"></div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
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Cheers,<br>
√</div>
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</div></div></blockquote><div><br></div><div>Rémi<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div id="Signature"><div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><b><br></b></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<b>Viktor Klang</b></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Software Architect, Java Platform Group<br>
Oracle</div>
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<hr style="display:inline-block;width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> core-libs-dev <core-libs-dev-retn@openjdk.org> on behalf of Viktor Klang <viktor.klang@oracle.com><br><b>Sent:</b> Wednesday, 24 January 2024 14:34<br><b>To:</b> forax@univ-mlv.fr <forax@univ-mlv.fr><br><b>Cc:</b> core-libs-dev <core-libs-dev@openjdk.java.net>; Paul Sandoz <psandoz@openjdk.java.net><br><b>Subject:</b> Re: Gatherer: spliterator characteristics are not propagated</font>
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<div class="x_elementToProof"><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Presuming that you mean mutating the Gatherer such that its behavior isn't stable, the difference
(at least to me) is that creating such a mutable Gatherer would violate the specification of Gatherer:
</span><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><a href="https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/stream/Gatherer.java#L63" id="LPlnk633725" target="_blank">https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/stream/Gatherer.java#L63</a></span><br data-mce-bogus="1"></div>
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Cheers,<br>
√</div>
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<b><br></b></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<b>Viktor Klang</b></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Software Architect, Java Platform Group<br>
Oracle</div>
</div>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> forax@univ-mlv.fr <forax@univ-mlv.fr><br><b>Sent:</b> Tuesday, 23 January 2024 21:04<br><b>To:</b> Viktor Klang <viktor.klang@oracle.com><br><b>Cc:</b> core-libs-dev <core-libs-dev@openjdk.java.net>; Paul Sandoz <psandoz@openjdk.java.net><br><b>Subject:</b> [External] : Re: Gatherer: spliterator characteristics are not propagated</font>
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<b>From: </b>"Viktor Klang" <viktor.klang@oracle.com><br>
<b>To: </b>"Remi Forax" <forax@univ-mlv.fr><br>
<b>Cc: </b>"core-libs-dev" <core-libs-dev@openjdk.java.net>, "Paul Sandoz" <psandoz@openjdk.java.net><br>
<b>Sent: </b>Monday, January 22, 2024 10:06:27 PM<br>
<b>Subject: </b>Re: Gatherer: spliterator characteristics are not propagated<br>
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The flags are in sync with the implementation because the only way to create a Gatherer if through the factory methods and those factory methods (and only them) compute the proper combination of SEQUENTIAL | STATELESS | GREEDY. A user should not be able to
set those flags. Only the flags KEEP_* are settable by a user.</div>
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But I presume this also requires to have a `int characteristics()`-method on the Gatherer interfacewhich means that users who are not using the factory methods will have full possibility of not only returning the flags, but returning any int.</div>
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<div>The current implementation suffers the same kind of issue, it's easy to write a mutable Gatherer and change the functions after creation, worst, right in the middle of a call to stream.gather(...).<br>
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<div>Perhaps the Gatherer interface should be sealed ? We did not have that option during the 1.8 timeframe, when the Collector API was created.<br>
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<span style="color:rgb(0,0,0)"><br></span></div>
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The stream implementation has a whole mechanism in place to propagate/preverse flags like SIZED, DISTINCT or SORTED. For me, discussing about the merit of this mechanism seems a little off topic. I would prefer the Gatherer to be a good citizen and works seemlessly
with the other intermediary operations.</div>
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<div class="x_x_elementToProof"><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">I can see where you're coming from here, but to me, adding API surface needs to pull its weight.</span></div>
<div class="x_x_elementToProof"><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">In this case I wasn't convinced that it did, hence we're having this conversation.
<span id="x_x_🙂">\uD83D\uDE42</span><br></span></div>
<div class="x_x_elementToProof"><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Cheers,<br>
√</span></div>
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<div>regards,<br>
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<div>Rémi<br>
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<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><b><br></b></span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><b>Viktor Klang</b></span></div>
<div><span style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Software Architect, Java Platform Group<br>
Oracle</span></div>
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<div style="direction:ltr"><span style="font-family:Calibri,sans-serif; font-size:11pt; color:rgb(0,0,0)"><b>From:</b> forax@univ-mlv.fr <forax@univ-mlv.fr><br><b>Sent:</b> Monday, 22 January 2024 19:56<br><b>To:</b> Viktor Klang <viktor.klang@oracle.com><br><b>Cc:</b> core-libs-dev <core-libs-dev@openjdk.java.net>; Paul Sandoz <psandoz@openjdk.java.net><br><b>Subject:</b> [External] : Re: Gatherer: spliterator characteristics are not propagated</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
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<span style="font-family:Helvetica,Arial,sans-serif; font-size:12pt; color:rgb(0,0,0)"><b>From:
</b>"Viktor Klang" <viktor.klang@oracle.com><br><b>To: </b>"Remi Forax" <forax@univ-mlv.fr><br><b>Cc: </b>"core-libs-dev" <core-libs-dev@openjdk.java.net>, "Paul Sandoz" <psandoz@openjdk.java.net><br><b>Sent: </b>Monday, January 22, 2024 4:22:11 PM<br><b>Subject: </b>Re: Gatherer: spliterator characteristics are not propagated<br></span></blockquote>
<blockquote style="margin-left:5px; padding-left:5px; border-left:2px solid rgb(16,16,255)">
<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Hi Rémi,</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Hello,</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
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<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">For instance, stateless is neither recessive nor dominant, since the composition of two stateless operations is only ever
stateless if they both are greedy as well: <a href="https://urldefense.com/v3/__https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/stream/Gatherers.java*L588__;Iw!!ACWV5N9M2RV99hQ!Lm52jd6kovd5t-cmrqqSLiRcIajBGXLxh85LO3eeiL6UxbKZuNPcUnO6z2i0FzMEoNr7U-cOBuWPCjo57FVW$" id="OWA0b03fd05-7fe2-6c29-b6f7-9f3306789017" class="x_x_OWAAutoLink" target="_blank">
https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/stream/Gatherers.java#L588</a></span><br>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Okay, so choosing SEQUENTIAL vs PARALELLIZABLE is not that important given that the combination is ad-hoc, reflecting the characterristics is enough.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
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<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">So even if making it represented as ints (more like Spliterator, rather than Collector) makes things faster, it's still
both work to track, propagate, and also becomes a side-channel that needs to remain in sync with the actual implementation of the logic.</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">The flags are in sync with the implementation because the only way to create a Gatherer if through the factory methods and those factory methods (and only them) compute
the proper combination of SEQUENTIAL | STATELESS | GREEDY. A user should not be able to set those flags. Only the flags KEEP_* are settable by a user.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
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<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">One could argue that logic such as: someCollection.stream().map(…).count() is a performance bug/inefficiency in an of
itself as it would be faster to do someCollection.size().</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">The stream implementation has a whole mechanism in place to propagate/preverse flags like SIZED, DISTINCT or SORTED. For me, discussing about the merit of this mechanism
seems a little off topic. I would prefer the Gatherer to be a good citizen and works seemlessly with the other intermediary operations.</span></div>
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Cheers,<br>
√</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
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<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<b><br></b></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<b>Viktor Klang</b></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Software Architect, Java Platform Group<br>
Oracle</div>
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<span style="font-family:Helvetica,Arial,sans-serif; font-size:12pt; color:rgb(0,0,0)"><b>From:
</b>"Viktor Klang" <viktor.klang@oracle.com><br><b>To: </b>"Remi Forax" <forax@univ-mlv.fr><br><b>Cc: </b>"core-libs-dev" <core-libs-dev@openjdk.java.net>, "Paul Sandoz" <psandoz@openjdk.java.net><br><b>Sent: </b>Monday, January 22, 2024 4:22:11 PM<br><b>Subject: </b>Re: Gatherer: spliterator characteristics are not propagated<br></span></blockquote>
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<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Hi Rémi,</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Hello,</span></div>
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<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">For instance, stateless is neither recessive nor dominant, since the composition of two stateless operations is only ever
stateless if they both are greedy as well: <a href="https://urldefense.com/v3/__https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/stream/Gatherers.java*L588__;Iw!!ACWV5N9M2RV99hQ!Lm52jd6kovd5t-cmrqqSLiRcIajBGXLxh85LO3eeiL6UxbKZuNPcUnO6z2i0FzMEoNr7U-cOBuWPCjo57FVW$" id="OWA28d62600-62df-f108-f943-a3c7e4d8d976" class="x_x_OWAAutoLink" target="_blank">
https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/stream/Gatherers.java#L588</a></span><br>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Okay, so choosing SEQUENTIAL vs PARALELLIZABLE is not that important given that the combination is ad-hoc, reflecting the characterristics is enough.</span></div>
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So even if making it represented as ints (more like Spliterator, rather than Collector) makes things faster, it's still both work to track, propagate, and also becomes a side-channel that needs to remain in sync with the actual implementation of the logic.</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">The flags are in sync with the implementation because the only way to create a Gatherer if through the factory methods and those factory methods (and only them) compute
the proper combination of SEQUENTIAL | STATELESS | GREEDY. A user should not be able to set those flags. Only the flags KEEP_* are settable by a user.</span></div>
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One could argue that logic such as: someCollection.stream().map(…).count() is a performance bug/inefficiency in an of itself as it would be faster to do someCollection.size().</div>
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<span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">The stream implementation has a whole mechanism in place to propagate/preverse flags like SIZED, DISTINCT or SORTED. For me, discussing about the merit of this mechanism
seems a little off topic. I would prefer the Gatherer to be a good citizen and works seemlessly with the other intermediary operations.<br></span>
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Cheers,<br>
√</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">regards,</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Rémi</span></div>
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<b>Viktor Klang</b></div>
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Software Architect, Java Platform Group<br>
Oracle</div>
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<div id="x_x_x_divRplyFwdMsg" dir="ltr"><span style="font-family:Calibri,sans-serif; font-size:11pt; color:rgb(0,0,0)"><b>From:</b> forax@univ-mlv.fr <forax@univ-mlv.fr><br><b>Sent:</b> Saturday, 20 January 2024 17:40<br><b>To:</b> Viktor Klang <viktor.klang@oracle.com><br><b>Cc:</b> core-libs-dev <core-libs-dev@openjdk.java.net>; Paul Sandoz <psandoz@openjdk.java.net><br><b>Subject:</b> [External] : Re: Gatherer: spliterator characteristics are not propagated</span>
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<span style="font-family:Helvetica,Arial,sans-serif; font-size:12pt; color:rgb(0,0,0)"><b>From:
</b>"Viktor Klang" <viktor.klang@oracle.com><br><b>To: </b>"Remi Forax" <forax@univ-mlv.fr><br><b>Cc: </b>"core-libs-dev" <core-libs-dev@openjdk.java.net>, "Paul Sandoz" <psandoz@openjdk.java.net><br><b>Sent: </b>Thursday, January 18, 2024 5:14:38 PM<br><b>Subject: </b>Re: Gatherer: spliterator characteristics are not propagated<br></span></blockquote>
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And for A.andThen(B), A.flags & B.flags should work, the stream is sorted if both gatherers keep it sorted.</div>
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That is unfortunately not the case. That would presume that you can implement the composition such that it can preserve all the common flags. Some flags could be "dominant" and some "recessive" to use genetics nomenclature.</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Some flags of the stream pipeline are "recessive", mainly SHORT_CIRCUIT, but not the characteristics of the Gatherer which can have the corresponding "dominant" flag,
GREEDY, in this case.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">And the same for sequential, the flag should be PARALELIZABLE and not SEQUENTIAL.</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">The idea is that the Gatherer characteristics can have the same bit set at the same position as the stream op flags (as defined by StreamOpFlag).</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">So KEEP_DISTINCT is in position 0, KEEP_SORTED in in position 2 and KEEP_SIZED is in position 3.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">For GREEDY, we use the same position as SHORT_CIRCUIT and we will flip the bit (using XOR) when we want to extract the stream op flags from the characteristics</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">All the factory methods call the generic of() with a combination of PARALELIZABLE and STATELESS and the user can adds the characteristics GREEDY, KEEP_DISTINCT, KEEP_SORTED
and KEEP_SIZED (otherwise an exception should be raised).</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">In StreamOpFlag, there are two unused positions (14 and 15), that's perfect for our two new states PARALELIZABLE and STATELESS, so no problem here (technically we can
also reuse positions of the Spliterator characteristic given that those flags are masked before being sent to the GathererOp super constructor).</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">The way to transform a Gatherer characteristics op to a stream flags op is to flip the bits corresponding to SHORT_CIRCUIT, add the highter bit of all flags but SHORT-CIRCUIT
(because stream op flags are encoded using 2 bits) and mask to only retain SHORT_CIRCUIT, KEEP_DISTINCT, KEEP_SORTED and KEEP_SIZED.</span></div>
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<pre><div><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,98,122)">toOpFlags</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">^ </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SHORT_CIRCUIT_MASK</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) | </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>HIGHER_BITS</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) & </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STREAM_OP_MASK</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br>}</span></div></pre>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">see below for a full script.</span></div>
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I suppose that if those flags already exist, it's because they have a purpose and i do not understand how it can make the other operations slower.</div>
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Extra invocations, extra storage, and extra composition overhead is not free. Since Stream is one-shot you need to include the construction cost with the execution cost. For something like an empty Stream construction cost scan be 90+% of the total costs.</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">If you create a Gatherer, the characteristics is a constant (so the validity check is removed, it's just a mask and a test) so the result of calling toOpFlags() is a
constant too.</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">If the factory method is not inlined, the cost is 3 bitwise operations which is I believe faster than the "instanceof Greedy" used in the current code.</span></div>
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Cheers,<br>
√</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">regards,</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Rémi</span></div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">---</span></div>
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<pre><div><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public class </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">GathererFlag </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">{<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(140,140,140)"><i>// cut and paste from StreamOpFlag<br> /**<br> * The bit pattern for setting/injecting a flag.<br> */<br></i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SET_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">0b01</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(140,140,140)"><i>/**<br> * The bit pattern for clearing a flag.<br> */<br></i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>CLEAR_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">0b10</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(140,140,140)"><i>/**<br> * The bit pattern for preserving a flag.<br> */<br></i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>PRESERVE_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">0b11</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br><br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,98,122)">position</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">opFlagSet</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">Integer</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.<i>numberOfTrailingZeros</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">opFlagSet</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) >> </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br> }<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>DISTINCT_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= <i>position</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">StreamOpFlag</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>IS_DISTINCT</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SORTED_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= <i>position</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">StreamOpFlag</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>IS_SORTED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SIZED_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= <i>position</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">StreamOpFlag</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>IS_SIZED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SHORT_CIRCUIT_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= <i>position</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">StreamOpFlag</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>IS_SHORT_CIRCUIT</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STATELESS_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">14</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>PARELLIZABLE_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">15</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>PARELLIZABLE </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SET_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< (</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>PARELLIZABLE_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STATELESS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SET_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< (</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STATELESS_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>GREEDY </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SET_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< (</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SHORT_CIRCUIT_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_DISTINCT </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SET_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< (</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>DISTINCT_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SORTED </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SET_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< (</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SORTED_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SIZED </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SET_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< (</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SIZED_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SHORT_CIRCUIT_MASK </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SET_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< (</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SHORT_CIRCUIT_POSITION </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)"><< </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(140,140,140)"><i>// no GREEDY here<br></i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>HIGHER_BITS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= (</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>PARELLIZABLE </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STATELESS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_DISTINCT </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SORTED </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SIZED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) << </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">private static final int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STREAM_OP_MASK </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">=<br> ((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>GREEDY </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_DISTINCT </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SORTED </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SIZED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) << </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(23,80,235)">1</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) |<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>GREEDY </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_DISTINCT </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SORTED </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SIZED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">String </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,98,122)">toString</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">Stream</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.<i>of</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">)<br> .<</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">String</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">>mapMulti((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">f</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">, </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">consumer</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) -> {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">f </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">& </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>PARELLIZABLE</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) == </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>PARELLIZABLE</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">consumer</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.accept(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"PARELLIZABLE"</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br> }<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">f </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">& </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STATELESS</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) == </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STATELESS</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">consumer</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.accept(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"STATELESS"</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br> }<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">f </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">& </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>GREEDY</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) == </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>GREEDY</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">consumer</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.accept(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"GREEDY"</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br> }<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">f </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">& </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_DISTINCT</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) == </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_DISTINCT</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">consumer</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.accept(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"KEEP_DISTINCT"</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br> }<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">f </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">& </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SORTED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) == </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SORTED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">consumer</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.accept(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"KEEP_SORTED"</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br> }<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">f </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">& </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SIZED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) == </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SIZED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">consumer</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.accept(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"KEEP_SIZED"</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">);<br> }<br> })<br> .collect(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">Collectors</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.<i>joining</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">", "</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">));<br> }<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,98,122)">toOpFlags</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">((</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">^ </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>SHORT_CIRCUIT_MASK</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) | </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>HIGHER_BITS</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) & </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STREAM_OP_MASK</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br>}<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">public static </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">String </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,98,122)">toOpFlagsString</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">int </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">opFlags</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">Arrays</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.<i>stream</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">StreamOpFlag</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.<i>values</i>())<br>.map(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">op </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">-> {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">op</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.isPreserved(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(133,22,145)">opFlags</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">)) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"preserved " </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">+ </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">op</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br>}<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">op</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.isCleared(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(133,22,145)">opFlags</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">)) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"cleared " </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">+ </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">op</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br>}<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">if </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">op</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.isKnown(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(133,22,145)">opFlags</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">)) {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"set " </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">+ </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">op</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br>}<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">return </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">"?? " </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">+ </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">op</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br>})<br>.collect(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">Collectors</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.<i>joining</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(6,125,23)">", "</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">));<br>}<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">void </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,98,122)">main</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">() {<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">var </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>PARELLIZABLE </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STATELESS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>GREEDY </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_DISTINCT </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SORTED </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SIZED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">System</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>out</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.println(<i>toOpFlagsString</i>(<i>toOpFlags</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">)));<br><br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,51,179)">var </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics2 </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">= </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>STATELESS </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_DISTINCT </i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">| </span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>KEEP_SIZED</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">;<br></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">System</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(135,16,148)"><i>out</i></span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">.println(<i>toOpFlagsString</i>(<i>toOpFlags</i>(</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(0,0,0)">characteristics2</span><span style="font-family:"JetBrains Mono",monospace; font-size:9.8pt; color:rgb(8,8,8)">)));<br>}<br>}</span></div></pre>
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<b><br></b></div>
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<b>Viktor Klang</b></div>
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Software Architect, Java Platform Group<br>
Oracle</div>
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<div id="x_x_x_x_divRplyFwdMsg" dir="ltr"><span style="font-family:Calibri,sans-serif; font-size:11pt; color:rgb(0,0,0)"><b>From:</b> forax@univ-mlv.fr <forax@univ-mlv.fr><br><b>Sent:</b> Thursday, 18 January 2024 16:17<br><b>To:</b> Viktor Klang <viktor.klang@oracle.com><br><b>Cc:</b> core-libs-dev <core-libs-dev@openjdk.java.net>; Paul Sandoz <psandoz@openjdk.java.net><br><b>Subject:</b> [External] : Re: Gatherer: spliterator characteristics are not propagated</span>
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<span style="font-family:Helvetica,Arial,sans-serif; font-size:12pt; color:rgb(0,0,0)"><b>From:
</b>"Viktor Klang" <viktor.klang@oracle.com><br><b>To: </b>"Remi Forax" <forax@univ-mlv.fr><br><b>Cc: </b>"core-libs-dev" <core-libs-dev@openjdk.java.net>, "Paul Sandoz" <psandoz@openjdk.java.net><br><b>Sent: </b>Thursday, January 18, 2024 3:36:07 PM<br><b>Subject: </b>Re: Gatherer: spliterator characteristics are not propagated<br></span></blockquote>
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I suspect that it is a rather slippery slope, once KEEP-flags are added, then others will want to be able to have INJECT-flags, and then people might have different opinions w.r.t. the default should be to clear all flags etc.</div>
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And that's even before one looks at the composition-part of it, what are the flags for A.andThen(B)? (then extrapolate to N compositions and the available set of flags always approaches 0)</div>
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I spent quite a bit of time on this and in the end tracking all this info, and making sure that the flags of implementations correspond to the actual behavior, just ended up costing performance for most streams and introduced an extra dimension to creation
and maintenance which I had a hard time justifying.</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">It can be a slippery slope if we were designing from the ground up but the stream implementation already exists and SORTED, DISTINCT and SIZED are the flags that are
already tracked by the current implementation.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Currently only SHORT_CIRCUIT is set (if not greedy),</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">see
<a href="https://urldefense.com/v3/__https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/stream/GathererOp.java*L209__;Iw!!ACWV5N9M2RV99hQ!PhMxqlDzLWPRuwYc7ECRKNPVs0BtnoE-RdT-Jdkng7S-iFuERAHYcWvJ-OMKGLrkPdSrUl3xj1R9ypyeqeWI$" id="OWA1de4dae1-4def-061e-101c-71b3a0489acb" class="x_x_x_x_OWAAutoLink" target="_blank">
https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/stream/GathererOp.java#L209</a></span><br>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">And for A.andThen(B), A.flags & B.flags should work, the stream is sorted if both gatherers keep it sorted.</span></div>
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Making specific, rare, combinations of operations faster at the expense of making 99% of all others slower is a hard pill for most to swallow.</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">I suppose that if those flags already exist, it's because they have a purpose and i do not understand how it can make the other operations slower.</span></div>
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Cheers,<br>
√</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">regards,</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Rémi</span></div>
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<b><br></b></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<b>Viktor Klang</b></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Software Architect, Java Platform Group<br>
Oracle</div>
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<hr style="display:inline-block; width:98%">
<div id="x_x_x_x_x_divRplyFwdMsg" dir="ltr"><span style="font-family:Calibri,sans-serif; font-size:11pt; color:rgb(0,0,0)"><b>From:</b> forax@univ-mlv.fr <forax@univ-mlv.fr><br><b>Sent:</b> Thursday, 18 January 2024 10:28<br><b>To:</b> Viktor Klang <viktor.klang@oracle.com><br><b>Cc:</b> core-libs-dev <core-libs-dev@openjdk.java.net>; Paul Sandoz <psandoz@openjdk.java.net><br><b>Subject:</b> [External] : Re: Gatherer: spliterator characteristics are not propagated</span>
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<span style="font-family:Helvetica,Arial,sans-serif; font-size:12pt; color:rgb(0,0,0)"><b>From:
</b>"Viktor Klang" <viktor.klang@oracle.com><br><b>To: </b>"Remi Forax" <forax@univ-mlv.fr>, "core-libs-dev" <core-libs-dev@openjdk.java.net><br><b>Sent: </b>Wednesday, January 17, 2024 8:48:07 PM<br><b>Subject: </b>Re: Gatherer: spliterator characteristics are not propagated<br></span></blockquote>
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Hi Rémi,</div>
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<div><span style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">You can find some of my benches here:
<a href="https://urldefense.com/v3/__https://github.com/openjdk/jdk/tree/master/test/micro/org/openjdk/bench/java/util/stream/ops/ref__;!!ACWV5N9M2RV99hQ!JJy6F9NoL6wKZQK5158up_fTRvH8X7F6JK8T7Euuf8vzbSQbr23eWa9S_yb61ksONVrLrdesCF_au5zyje2l$" id="OWA64353d4a-525b-69fa-1b1c-136f7ddf895a" class="x_x_x_x_OWAAutoLink" target="_blank">
https://github.com/openjdk/jdk/tree/master/test/micro/org/openjdk/bench/java/util/stream/ops/ref</a></span><br>
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Initially I had Characteristics such as ORDERED etc on Gatherer but it just didn't end up worth it when looking at the bench results over a wide array of stream sizes and number of operations.</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">I think there are 3 gatherer characteristics that make sense: KEEP_SORTED, KEEP_DISTINCT and KEEP_SIZED,</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">all of them say that if the stream was sorted/distinct/sized then the stream returned by a call to gather() is still sorted (with the same comparator), distinct or sized.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">As examples, map() is KEEP_SIZED, filter() is KEEP_SORTED | KEEP_DISTINCT and windowFixed is KEEP_DISTINCT.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">[CC Paul, so he can correct me if i'm saying something stupid]</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Now for the benchmarks, it depends what you want to measure, benchmarking streams is tricky. This is what i know about benchmarking streams.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">First, the JIT has two ways to profile types at runtime,</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Either a method takes a function as parameter</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> void map(Function function) {</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> function.apply(...)</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> }</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">and when map is called with a subtype of Function, the JIT will propagate the exact type when map is inlined,</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Or a method use a field</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> class Op {</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> Function function;</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> void map() {</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> function.apply(...)</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> }</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> }</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">in that case, the VM records the profile of function.apply() and if there are more than two different profiles, the VM declare profile poluttion and do not try to optimize.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">The Stream implementation tries very hard to use only parameters instead of fields, that's why it does not use classical Iterator that are pull iterator (a filter iterator
requires a field) but a Spliterator which is a push iterator, the element is sent as parameter of the consumer.That's also why collect does not use the builder pattern (that accumulate values in fields) but a Collector that publish the functions to be called
as parameter.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Obvisously, this is more complex than that, a Collector stores the functions in fields so it should not work well but the implementation uses a record that plays well
with escape analysis. Escape analysis see the fields of an instance as parameters so the functions of a Collector are correctly propagated (if the escape analysis works). And lambdas are using invokedynamic, and the VM tries really hard to inline invokedynamic,
so lambdas (that captures value or not) are routinely fully inlined with the intermediate operation of a stream.</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">In your tests, i've not seen comparaisons between an existing method like map() or filter() followed by a sorted()/distinct()/count()/toList(), i.e. operations where
the characteristics KEEP_* have an impact and their equivalent using a Gatherer.</span></div>
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Cheers,<br>
√</div>
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<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">regards,</span></div>
<div><span style="font-family:arial,helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">Rémi</span></div>
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<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<b>Viktor Klang</b></div>
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Software Architect, Java Platform Group<br>
Oracle</div>
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<div id="x_x_x_x_x_x_divRplyFwdMsg" dir="ltr"><span style="font-family:Calibri,sans-serif; font-size:11pt; color:rgb(0,0,0)"><b>From:</b> core-libs-dev <core-libs-dev-retn@openjdk.org> on behalf of Remi Forax <forax@univ-mlv.fr><br><b>Sent:</b> Wednesday, 17 January 2024 16:48<br><b>To:</b> core-libs-dev <core-libs-dev@openjdk.java.net><br><b>Subject:</b> Gatherer: spliterator characteristics are not propagated</span>
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<div><span style="font-family:Helvetica,Arial,sans-serif; font-size:11pt; color:rgb(0,0,0)">While doing some benchmarking of the Gatherer API, i've found that the characteristics of the spliterator was not propagated by the method Stream.gather() making the
stream slower than it should.<br><br>
As an example, there is no way when reimplementing map() using a Gatherer to say that this intermediate operation keep the size, which is important if the terminal operation is toList() because if the size is known, toList() will presize the List and avoid
the creation of an intermediary ArrayList.<br><br>
See <a href="https://urldefense.com/v3/__https://github.com/forax/we_are_all_to_gather/blob/master/src/main/java/com/gihtub/forax/wearealltogather/bench/MapGathererBenchmark.java__;!!ACWV5N9M2RV99hQ!JJy6F9NoL6wKZQK5158up_fTRvH8X7F6JK8T7Euuf8vzbSQbr23eWa9S_yb61ksONVrLrdesCF_auzwTY8aB$" id="OWA3c51d081-a9cb-0bb5-f558-a69a870fa1a1" class="x_x_x_x_OWAAutoLink" target="_blank">
https://github.com/forax/we_are_all_to_gather/blob/master/src/main/java/com/gihtub/forax/wearealltogather/bench/MapGathererBenchmark.java</a><br><br>
I think that adding a way to propagate the spliterator characteristics through a Gatherer would greatly improve the performance of commons streams (at least all the ones that end with a call to toList).<br><br>
I have some idea of how to do that, but I prefer first to hear if i've overlook something and if improving the performance is something worth changing the API.<br><br>
regards,<br>
Rémi</span></div>
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