• Type: Improvement
    • Status: Open
    • Priority: Minor
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: 1.0.0
    • Component/s: None
    • Labels:


      Motivation: Kotlin has recently gained a lot of popularity and people are really starting to talk about it and see its merits; and language-wise it should be perfect for writing data-transformation code as it has better support for functional programming and useful type stuff than Java, without the performance overhead and implicit mysteries of Scala.

      Attached is a patch for a proof-of-concept Kotlin API for Crunch. It makes heavy use of inlined functions so that the compiled bytecode ends up looking a lot like standard Crunch code (I ran it through a decompiler), and should be just as performant.

      It also uses reified type parameters to construct PTypes automatically from TypeReferences, so in most cases it's not necessary to provide a PType for transformations.

      See the example job and unit tests to get a quick idea of what kind of thing is possible.

      I've decided to share an unfinished patch with you all so that I can get some feedback if we think this is a useful addition to the Crunch project at all, and whether the general approach seems sensible.

      Still left TODO (if we decide to finish this and add it):

      • PGroupedTable API
      • Extensible PType inference (I'm thinking something like register<MyType>(pTypeForMyType))
      • Support for data classes via kotlin-reflect
      • Fill in any other gaps (mapWithContext, counters, ... ?)


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          • Assignee:
            davw David Whiting
            davw David Whiting
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