streamly/Changelog.md

Unreleased

Breaking changes

• Change the semantics of the Semigroup instance for InterleavedT, AsyncT and ParallelT. The new semantics are as follows:

  • For InterleavedT, <> operation interleaves two streams
  • For AsyncT, <> now concurrently merges two streams in a left biased manner using demand based concurrency.
  • For ParallelT, the <> operation now concurrently meges the two streams in a fairly parallel manner.

  To adapt to the new changes, replace <> with append wherever it is used for streams other than StreamT.

• Change the semantics of Alternative instance. The <|> operator now has a different behavior for each type. See the documentation for more details. To adapt to this change replace any usage of <|> with parallel and empty with nil.

• Streams now default to the SerialT type unless explicitly specified using a type combinator. This also means that you do not have to explicitly specify a stream type now, the default will be used. This changes reduces puzzling type errors for beginners. It includes the following two changes:

  • Change the type of all stream elimination functions to SerialT. This makes sure that the stream type is always fixed at all exits.
  • Change the type combinators to only fix the argument stream type and the resulting stream type remains polymorphic.

• Change the type of foldrM to make it consistent with foldrM in base.

Deprecations

• Deprecate and rename the following symbols:
  • StreamT to SerialT
  • runStreamT to runSerialT
  • ZipStream to ZipSerial
  • runZipStream to runZipSerial
  • AsyncT to AParallelT
  • runAsyncT to runAParallelT
  • asyncly to aparallely
  • Streaming to IsStream
  • runStreaming to runStream
  • <=> to interleave
  • <| to aparallel
  • each to fromFoldable
  • scan to scanx
  • foldl to foldx
  • foldlM to foldxM

Enhancements

• Add the following functions:
  • scanl' strict left scan
  • foldl' strict left fold
  • foldlM' strict left fold with a monadic fold function
  • append run two streams serially one after the other
  • parallel run two streams in parallel

0.1.2

Enhancements

• Add iterate, iterateM stream operations

Bug Fixes

• Fixed a bug that casued unexpected behavior when pure was used to inject values in Applicative composition of ZipStream and ZipAsync types.

0.1.1

Enhancements

• Make cons right associative and provide an operator form .: for it
• Add null, tail, reverse, replicateM, scan stream operations
• Improve performance of some stream operations (foldl, dropWhile)

Bug Fixes

• Fix the product operation. Earlier, it always returned 0 due to a bug
• Fix the last operation, which returned Nothing for singleton streams

0.1.0

• Initial release