This project is an iteratee implementation for Cats that began as a port of Scalaz's iteratee package, although the API and implementation are now very different from Scalaz's. There are API docs (but they're a work in progress), and I've published a blog post introducing the project.
The motivations for the port are similar to those for circe—in particular I'm aiming for a more consistent API, better performance, and better documentation.
Note that this library doesn't support many of the use cases that fs2 (formerly Scalaz Stream) is designed to handle. It doesn't support nondeterministic reading from multiple streams, for example, and in general is a less appropriate choice for situations where concurrency and parallelism are primary goals. Where the use cases of fs2 and this library do overlap, however, it's often likely to be a simpler, faster solution.
The initial performance benchmarks look promising. For example, here are the throughput results for
summing a sequence of numbers with this library (I), Scalaz Stream (S), scalaz-iteratee (Z),
play-iteratee (P), the collections library (C), and fs2 (F). Higher numbers
are better.
Benchmark Mode Cnt Score Error Units
InMemoryBenchmark.sumInts0I thrpt 80 17451.805 ± 144.119 ops/s
InMemoryBenchmark.sumInts1S thrpt 80 80.756 ± 0.291 ops/s
InMemoryBenchmark.sumInts2Z thrpt 80 311.448 ± 1.380 ops/s
InMemoryBenchmark.sumInts3P thrpt 80 106.916 ± 1.745 ops/s
InMemoryBenchmark.sumInts4C thrpt 80 20780.020 ± 124.742 ops/s
InMemoryBenchmark.sumInts5F thrpt 80 18916.338 ± 58.642 ops/s
And the results for collecting the first 10,000 values from an infinite stream of non-negative
numbers into a Vector:
Benchmark Mode Cnt Score Error Units
StreamingBenchmark.takeLongs0I thrpt 80 1252.230 ± 3.309 ops/s
StreamingBenchmark.takeLongs1S thrpt 80 64.888 ± 0.229 ops/s
StreamingBenchmark.takeLongs2Z thrpt 80 227.533 ± 1.394 ops/s
StreamingBenchmark.takeLongs3P thrpt 80 1.366 ± 0.005 ops/s
StreamingBenchmark.takeLongs4C thrpt 80 3000.368 ± 4.800 ops/s
StreamingBenchmark.takeLongs5F thrpt 80 117.318 ± 0.379 ops/s
And allocation rates (lower is better):
Benchmark Mode Cnt Score Error Units
InMemoryBenchmark.sumInts0I:gc.alloc.rate.norm thrpt 10 161656.027 ± 0.001 B/op
InMemoryBenchmark.sumInts1S:gc.alloc.rate.norm thrpt 10 57413029.853 ± 0.463 B/op
InMemoryBenchmark.sumInts2Z:gc.alloc.rate.norm thrpt 10 16881441.657 ± 0.499 B/op
InMemoryBenchmark.sumInts3P:gc.alloc.rate.norm thrpt 10 14007882.247 ± 253736.629 B/op
InMemoryBenchmark.sumInts4C:gc.alloc.rate.norm thrpt 10 159864.022 ± 0.001 B/op
InMemoryBenchmark.sumInts5F:gc.alloc.rate.norm thrpt 10 170832.024 ± 0.001 B/op
Benchmark Mode Cnt Score Error Units
StreamingBenchmark.takeLongs0I:gc.alloc.rate.norm thrpt 10 5924360.668 ± 46.481 B/op
StreamingBenchmark.takeLongs1S:gc.alloc.rate.norm thrpt 10 67926671.128 ± 0.052 B/op
StreamingBenchmark.takeLongs2Z:gc.alloc.rate.norm thrpt 10 27287730.054 ± 0.130 B/op
StreamingBenchmark.takeLongs3P:gc.alloc.rate.norm thrpt 10 1206116390.400 ± 250.142 B/op
StreamingBenchmark.takeLongs4C:gc.alloc.rate.norm thrpt 10 526752.154 ± 0.001 B/op
StreamingBenchmark.takeLongs5F:gc.alloc.rate.norm thrpt 10 47206075.959 ± 0.047 B/op
iteratee.io is licensed under the Apache License, Version 2.0 (the "License"); you may not use this software except in compliance with the License.
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