Claude
6b5a918278
gatherers/: windowFixed, windowSliding, fold, scan, mapConcurrent, a custom Gatherer (dedupeConsecutive, takeUntil), and a Collector-vs-Gatherer comparison. Verified: windowSliding emits one short window on a too-short stream rather than shrinking to empty like windowFixed; mapConcurrent waits for in-flight siblings to finish (~901ms) rather than cancelling them when one mapper throws. scoped-values/: ScopedValue API and rebinding, why plain threads (virtual or platform) do not inherit a binding while a StructuredTaskScope subtask does, and the memory cost vs InheritableThreadLocal measured two ways -- a noisy heap-delta first pass, then a precise jcmd GC.class_histogram object census (5 shared Carrier objects vs ~700,000 copied ThreadLocalMap/Entry objects for 100,000 threads). Companion code for the ankurm.com posts "Java Stream Gatherers (JEP 485)" and "Scoped Values vs ThreadLocal in Java 25: Migration Guide with Virtual Threads". Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01FtpJvZfg4nvLvtzgJTDWpB
10 lines
591 B
Plaintext
10 lines
591 B
Plaintext
$ java CollectorVsGatherer (JDK 25)
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Collectors.groupingBy totals = {amy=19.75, bo=23.99}
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CHECK ok : amy's total via groupingBy/summingDouble is 19.75
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CHECK ok : bo's total via groupingBy/summingDouble is 23.99
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scan -> filter -> map, one pipeline = [total=30, total=50, total=75]
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CHECK ok : scan feeding straight into filter/map in the same pipeline gives [total=30, total=50, total=75]
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windowFixed(2) over 7 elements, then collect(counting()) = 4
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CHECK ok : collect(counting()) after gather() proves the gather result is still a Stream you can collect further: 4 windows
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exit=0
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