JLine 3: Support camel-cased, acronym-style completion as previously

[SethTisue]

for example, previously System.rFOE would complete to System.runFinalizersOnExit, but it doesn't anymore

[SethTisue]

@retronym at scala/scala#8036 (comment) :

AFAICT JLine is filtering candidates on our behalf. without an obvious extension point to add our own strategy.

[lrytz]

It seems camelCase completers would be a sensible feature for JLine upstream? from jline/jline3#147

completers should return the full list of candidates, while matchers are responsible for the filtering [...]
The problem is that the matchers are not extensible
Would you mind working on a PR to make matchers extensible?

Then

I will [...] work on a PR

Not sure if this ever happened

[retronym]

Updated (and stable) link to the relevant part of the JLIne implenentation: https://github.com/jline/jline3/blob/2327d649ceb1bc8b4a4452b7821f1f0050503bc5/reader/src/main/java/org/jline/reader/impl/LineReaderImpl.java#L4434-L4477

[retronym]

@SethTisue Here's a sketch of how I think JLine could be customized: https://github.com/retronym/jline3/pull/1/files

[SethTisue]

removed from CompletionTest.scala for now:

  @Test
  def camelCompletions(): Unit = {
    val completer = setup()
    checkExact(completer, "object O { def theCatSatOnTheMat = 1 }; import O._; tCSO")("theCatSatOnTheMat")
    checkExact(completer, "object O { def getBlerganator = 1 }; import O._; blerga")("getBlerganator")
    checkExact(completer, "object O { def xxxxYyyyyZzzz = 1; def xxxxYyZeee = 1 }; import O._; xYZ")("", "xxxxYyyyyZzzz", "xxxxYyZeee")
    checkExact(completer, "object O { def xxxxYyyyyZzzz = 1; def xxxxYyyyyZeee = 1 }; import O._; xYZ")("xxxxYyyyyZzzz", "xxxxYyyyyZeee")
    checkExact(completer, "object O { class AbstractMetaFactoryFactory }; new O.AMFF")("AbstractMetaFactoryFactory")
    checkExact(completer, "object O { val DECIMAL_DIGIT_NUMBER = 0 }; import O._; L_")("DECIMAL_DIGIT_NUMBER")
    checkExact(completer, "object O { val _unusualIdiom = 0 }; import O._; _ui")("_unusualIdiom")
  }

  @Test
  def lenientCamelCompletions(): Unit = {
    val completer = setup()
    checkExact(completer, "object O { def theCatSatOnTheMat = 1 }; import O._; tcso")("theCatSatOnTheMat")
    checkExact(completer, "object O { def theCatSatOnTheMat = 1 }; import O._; sotm")("theCatSatOnTheMat")
    checkExact(completer, "object O { def theCatSatOnTheMat = 1 }; import O._; caton")("theCatSatOnTheMat")
    checkExact(completer, "object O { def theCatSatOnTheMat = 1; def catOnYoutube = 2 }; import O._; caton")("", "theCatSatOnTheMat", "catOnYoutube")
    checkExact(completer, "object O { def theCatSatOnTheMat = 1 }; import O._; TCSOTM")()
  }

  @Test
  def snakeCompletions(): Unit = {
    val completer = setup()
    checkExact(completer, "object O { final val THE_CAT_SAT_ON_THE_MAT = 1 }; import O._; TCSO")("THE_CAT_SAT_ON_THE_MAT")
    checkExact(completer, "object O { final val THE_CAT_SAT_ON_THE_MAT = 1 }; import O._; tcso")("THE_CAT_SAT_ON_THE_MAT")
    checkExact(completer, "object C { def isIdentifierIgnorable = ??? ; val DECIMAL_DIGIT_NUMBER = 0 }; import C._; iii")("isIdentifierIgnorable")
  }

  @Test
  def performanceOfLenientMatch(): Unit = {
    val completer = setup()
    val ident: String = "thisIsAReallyLongMethodNameWithManyManyManyManyChunks"
    checkExact(completer, s"($ident: Int) => tia")(ident)
  }

[retronym]

Assigning myself because this is a pet feature of mine that I'd like to have back. I might tinker with the upstream contribution to JLine. I'll post my status here if/when I actively start working on this, feel free to work-steal the back, Seth, if you want to work on it yourself.

[retronym]

Started the upstream PR: jline/jline3#626

[retronym]

I have a WIP PR that integrates the new JLine. So far so good. There are a few points to tidy up before I submit.