Created
February 7, 2012 09:27
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Scala Trait linearization
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Welcome to Scala version 2.9.1.r0-b20120125223512 (Java HotSpot(TM) 64-Bit Server VM, Java 1.7.0_02). | |
Type in expressions to have them evaluated. | |
Type :help for more information. | |
scala> trait A | |
defined trait A | |
scala> trait C extends A | |
defined trait C | |
scala> trait B extends A | |
defined trait B | |
scala> trait D extends B | |
defined trait D | |
scala> trait E extends C | |
defined trait E | |
scala> class D extends A with D with E | |
<console>:12: error: class D inherits itself | |
class D extends A with D with E | |
^ | |
scala> class F extends A with D with E | |
defined class F | |
scala> :power | |
** Power User mode enabled - BEEP BOOP SPIZ ** | |
** :phase has been set to 'typer'. ** | |
** scala.tools.nsc._ has been imported ** | |
** global._ and definitions._ also imported ** | |
** Try :help, vals.<tab>, power.<tab> ** | |
scala> intp.types("F").tpe.baseTypeSeq.toList | |
res0: List[$r.intp.global.Type] = List(F, D, E, C, B, ScalaObject, A, java.lang.Object, Any) | |
Tada! |
This works:
Welcome to Scala 2.12.4 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_144).
Type in expressions for evaluation. Or try :help.
scala> :paste
// Entering paste mode (ctrl-D to finish)
trait A { def foo = "a" }
trait B extends A { override def foo = "b" + super.foo }
trait D extends A { override def foo = "d" + super.foo }
trait C extends B { override def foo = "c" + super.foo }
class Qux extends A with C with B with D
// Exiting paste mode, now interpreting.
defined trait A
defined trait B
defined trait D
defined trait C
defined class Qux
scala> :power
Power mode enabled. :phase is at typer.
import scala.tools.nsc._, intp.global._, definitions._
Try :help or completions for vals._ and power._
scala> intp.exprTyper.typeOfTypeString("Qux").baseClasses
res0: List[$r.intp.exprTyper.repl.global.Symbol] = List(class Qux, trait D, trait C, trait B, trait A, class Object, class Any)
Documentation for the method is here: https://github.com/scala/scala/blob/v2.12.4/src/reflect/scala/reflect/internal/Types.scala#L909
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Getting following error:
scala> intp.types("F").tpe.baseTypeSeq.toList
:46: error: value types is not a member of scala.tools.nsc.interpreter.IMain
intp.types("F").tpe.baseTypeSeq.toList