Add skipLast(int) #156
Add skipLast(int) #156
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In general I'm not against adding such feature, but the implementation is quite poor, sorry. If you still like to improve it, you may use poor-man parallelism for general case (via AbstractSpliterator and friends), though it's possible to do better, but I expect to see SIZED/sequential and SIZED/SUBSIZED/parallel cases to be handled specially (probably via separate spliterators). Thank you.
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| @Override | ||
| public Spliterator<T> trySplit() { | ||
| return null; |
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Ignoring parallelism completely is not an option to my library.
| BlockingDeque<T> buffer = new LinkedBlockingDeque<>(n + 1); | ||
| Spliterator<T> source = this.spliterator(); | ||
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| return supply(StreamEx.of(new Spliterator<T>() { |
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Creating anonymous class you capture the outer this which is unnecessary.
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| @Override | ||
| public long estimateSize() { | ||
| return source.estimateSize() - n; |
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You could return negative size here which has no meaning.
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| @Override | ||
| public int characteristics() { | ||
| return source.characteristics(); |
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You don't delegate comparator in case if original spliterator is sorted.
| if (n == 0) | ||
| return supply(this); | ||
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| BlockingDeque<T> buffer = new LinkedBlockingDeque<>(n + 1); |
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Note that an optimized solution could be provided if the stream is SIZED/sequential or SIZED/SUBSIZED/parallel. In this case you don't need buffering at all as you know exactly how many elements are left. Also why concurrent buffer if you just refuse to parallelize? ArrayDeque (or simply Object[] array) would suffice and would be much faster.
| public int characteristics() { | ||
| return source.characteristics(); | ||
| } | ||
| })).sequential(); |
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A forEachRemaining method must be provided as it optimizes the common case (non-short-circuiting stream). In specific cases it could be much faster and memory friendly than tryAdvance.
| if (n == 0) | ||
| return this; | ||
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| BlockingDeque<Double> buffer = new LinkedBlockingDeque<>(n + 1); |
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Unnecessary boxing is absolutely not an option. You could just create an array of n elements.
Adds a new method that is the natural counterpart to
skip(long)