xeno-by

Answers http://stackoverflow.com/questions/10373318/mixing-in-a-trait-dynamically.

Compile as follows:
scalac Common_1.scala Macros_2.scala
scalac Common_1.scala Test_3.scala -cp <path to the result of the previous compilation>

Tested in 2.10.0-M3, will most likely not compile by the time 2.10.0 final is released, because we're actively rehashing the API. 
However the principles will remain the same in the final release, so the concept itself is okay.
upd. Code updated for 2.10.0-M7.
upd. Code updated for 2.10.0-RC1.

xeno-by

import scala.annotation.StaticAnnotation
import scala.reflect.macros.Macro
import language.experimental.macros

class body(tree: Any) extends StaticAnnotation

trait Macros extends Macro {
  import c.universe._

  def selFieldImpl = {

xeno-by

// PROBLEM STATEMENT

// Let's build Proxy[T], an object that can capture calls to methods of an underlying object.
// We want the proxy to be type-safe, i.e. we need to verify that the names of the calls
// and the arguments that are passed to those calls are well-typed wrt the type of the proxee.

object Test extends App {
  trait Foo { /* ... */ }
  val proxy: Proxy[Foo] = ???
  proxy.bar()

xeno-by

Keybase proof

I hereby claim:

• I am xeno-by on github.
• I am xeno_by (https://keybase.io/xeno_by) on keybase.
• I have a public key whose fingerprint is FE5A 8474 50B9 0939 A0A5 6C10 E512 F2A2 36EE 59D9

To claim this, I am signing this object:

xeno-by

Keybase proof

I hereby claim:

• I am xeno-by on github.
• I am xeno_by (https://keybase.io/xeno_by) on keybase.
• I have a public key whose fingerprint is FA14 7F45 5509 FC4D 106C 13FA AB30 CC8E F90D C4A8

To claim this, I am signing this object:

xeno-by

> publish
Generating Scalatex Sources...
[info] Resolving readme:readme_2.11:0.1-SNAPSHOT
[info] Resolution done
[info] Fetching artifacts
[info] Fetching artifacts: done
[info] Resolving org.scalameta:tokenizers_2.11:1.0.0-SNAPSHOT
[info] Resolution done
[info] Fetching artifacts
[info] Fetching artifacts: done

xeno-by

scala> 16:32 ~$ parse "x + (y)(z)"
[[syntax trees at end of parser]]// Scala source: tmpqW0GnW
package <empty> {
  class wrapper extends scala.AnyRef {
    def <init>() = {
      super.<init>();
      ()
    };
    x.$plus(y(z))
  }

xeno-by

BUILD FAILED
/localhome/jenkins/b/workspace/scala-checkin/build.xml:96: The following error occurred while executing this line:
/localhome/jenkins/b/workspace/scala-checkin/build-ant-macros.xml:8: The following error occurred while executing this line:
/localhome/jenkins/b/workspace/scala-checkin/build.xml:1420: The following error occurred while executing this line:
/localhome/jenkins/b/workspace/scala-checkin/build-ant-macros.xml:488: Test suite finished with 1 case failing:
fail - run/t6200.scala  [output differs]% scalac t6200.scala
% /home/jenkins/apps/jdk1.6.0_33-x64/jre/bin/java \
  -classpath \
  /localhome/jenkins/b/workspace/scala-checkin/test/files/run/t6200-run.obj:/localhome/jenkins/b/workspace/scala-checkin/build/pack/lib/scala-library.jar:/localhome/jenkins/b/workspace/scala-checkin/build/pack/lib/scala-reflect.jar:/localhome/jenkins/b/workspace/scala-checkin/build/pack/lib/scala-compiler.jar:/localhome/jenkins/b/workspace/scala-checkin/build/pack/lib/scalap.jar:/localhome/jenkins/b/workspace/s

xeno-by

19:15 ~/Projects/Master/sandbox (master)$ scala
Welcome to Scala version 2.11.0-20140115-080235-07e823ad97 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_65).
Type in expressions to have them evaluated.
Type :help for more information.

scala> q"class C(x: Int)"
res0: reflect.runtime.universe.ClassDef =
class C extends scala.AnyRef {
  <paramaccessor> private[this] val x: Int = _;
  def <init>(x: Int) = {

xeno-by

import scala.reflect.macros.WhiteboxContext
import scala.language.experimental.macros

object Macros {
  def impl(c: WhiteboxContext) = {
    import c.universe._
    val result = c.typecheck(q"""
      class C[T <: Int] {
        type Dummy123 = List[T]
      }