ssanj / zen   2.2.0

MIT License GitHub

Additional type information when you need it

Scala versions: 2.12

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The master computer from the Liberator

Zen is a Scala Macro that provides some additional type information when you need it.

Zen is inspired by macrocosm and Blakes 7.

Showing the type of an Expression

zen.t { List(1,2,3,4).map(_.toString).mkString }

which results in:

type: String

You can also name a given type:

zen.t("pair", { 1 -> "one" } )

which results in:

type "pair": (Int, String)

Explaining (desugaring) an Expression

z.explain {
    Option(1) match {
        case Some(x) => true
        case None => false
    }
}

results in:

code: scala.Option.apply[Int](1) match {
  case scala.Some((x @ _)) => true
  case scala.None => false
}

Showing the AST for an Expression

zen.ast { 1 :: 2 :: 3 :: Nil }

results in:

ast: Apply(TypeApply(Select(Apply(Apply(TypeApply(Select(Apply(TypeApply(Select(Select(Select(Select(Ident(scala), scala.collection), scala.collection.immutable), scala.collection.immutable.List), TermName("apply")), List(TypeTree())), List(Literal(Constant(1)), Literal(Constant(2)), Literal(Constant(3)))), TermName("flatMap")), List(TypeTree(), TypeTree())), List(Function(List(ValDef(Modifiers(PARAM), TermName("l1"), TypeTree(), EmptyTree)), Apply(Apply(TypeApply(Select(Apply(TypeApply(Select(Select(Select(Select(Ident(scala), scala.collection), scala.collection.immutable), scala.collection.immutable.List), TermName("apply")), List(TypeTree())), List(Literal(Constant(4)), Literal(Constant(5)), Literal(Constant(6)))), TermName("map")), List(TypeTree(), TypeTree())), List(Function(List(ValDef(Modifiers(PARAM), TermName("l2"), TypeTree(), EmptyTree)), Block(List(ValDef(Modifiers(SYNTHETIC | ARTIFACT), TermName("x$5"), TypeTree(), Ident(TermName("l1")))), Apply(TypeApply(Select(Block(List(ValDef(Modifiers(SYNTHETIC | ARTIFACT), TermName("x$4"), TypeTree(), Ident(TermName("l2")))), Apply(TypeApply(Select(Select(Select(Select(Ident(scala), scala.collection), scala.collection.immutable), scala.collection.immutable.Nil), TermName("$colon$colon")), List(TypeTree())), List(Ident(TermName("x$4"))))), TermName("$colon$colon")), List(TypeTree())), List(Ident(TermName("x$5")))))))), List(TypeApply(Select(Select(This(TypeName("immutable")), scala.collection.immutable.List), TermName("canBuildFrom")), List(TypeTree()))))))), List(TypeApply(Select(Select(This(TypeName("immutable")), scala.collection.immutable.List), TermName("canBuildFrom")), List(TypeTree())))), TermName("flatten")), List(TypeTree().setOriginal(Select(Ident(scala), scala.Int)))), List(TypeApply(Select(Select(Ident(scala), scala.Predef), TermName("$conforms")), List(TypeTree()))))

Showing Everything (Type, Explain and AST)

val source = zen.inspect(Observable.interval(1.second)
  .filter(_ % 2 == 0)
  .flatMap(x => Observable(x, x)))
  . take(10)

results in:

code: monix.reactive.Observable.interval(scala.concurrent.duration.`package`.DurationInt(1).second).filter(((x$2: Long) => x$2.%(2).==(0))).flatMap[Long](((x: Long) => monix.reactive.Observable.apply[Long](x, x)))
ast: Apply(TypeApply(Select(Apply(Select(Apply(Select(Select(Select(Ident(monix), monix.reactive), monix.reactive.Observable), TermName("interval")), List(Select(Apply(Select(Select(Select(Select(Ident(scala), scala.concurrent), scala.concurrent.duration), scala.concurrent.duration.package), TermName("DurationInt")), List(Literal(Constant(1)))), TermName("second")))), TermName("filter")), List(Function(List(ValDef(Modifiers(PARAM | SYNTHETIC), TermName("x$2"), TypeTree(), EmptyTree)), Apply(Select(Apply(Select(Ident(TermName("x$2")), TermName("$percent")), List(Literal(Constant(2)))), TermName("$eq$eq")), List(Literal(Constant(0))))))), TermName("flatMap")), List(TypeTree())), List(Function(List(ValDef(Modifiers(PARAM), TermName("x"), TypeTree(), EmptyTree)), Apply(TypeApply(Select(Select(Select(Ident(monix), monix.reactive), monix.reactive.Observable), TermName("apply")), List(TypeTree())), List(Ident(TermName("x")), Ident(TermName("x")))))))
type: monix.reactive.Observable[Long]

Showing the structure of a Case Class

case class Age(value: Int)
case class Name(value: String)
case class Person(title: String, name: Name, age: Age, address: Address)
case class Address(street: Street)
case class No(value: Int)
case class StreetName(value: String)
case class Street(no: No, name: StreetName)
class Dog(name: String)

val p1 = Person("mr", Name("Bob"), Age(31), Address(Street(No(10), StreetName("Midtown"))))

zen.structure(p1)

results in:

structure: Person(title:String, name:Name, age:Age, address:Address)
Name(value:String)
Age(value:Int)
Address(street:Street)
Street(no:No, name:StreetName)
No(value:Int)
StreetName(value:String)

Installation

Bintray

Add the following to your build.sbt:

libraryDependencies += "net.ssanj" %% "zen" % "2.0.0"

Local

Clone this repo and install it locally with:

sbt publishLocal

You can then include it in any SBT project as per usual:

libraryDependencies += "net.ssanj" %% "zen" % "3.0.0"

Publishing

To publish a new version perform the following tasks:

zen/publish
zen/bintrayRelease

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2 Dependencies

No Dependent