Macro types for the impatient

macro-apply-dynamic.scala

~/code/scala build/quick/bin/scala -Xexperimental -Xmacros
Welcome to Scala version 2.10.0-M2-0045-g4573e06a27-2012-02-25 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_29).
Type in expressions to have them evaluated.
Type :help for more information.

scala> val methods = Set("foo", "bar")
methods: scala.collection.immutable.Set[String] = Set(foo, bar)

scala> object Dyno extends Dynamic { 
  def macro applyDynamic(mn: String)(args: Any*) = mn match { 
    case Literal(Constant(x: String)) if methods(x) => 
      Literal(Constant(true))
    case _ => sys.error("no dice")
  } 
}
defined module Dyno

scala> Dyno.foo
dynatype: $line2.$read.$iw.$iw.Dyno.applyDynamic("foo")()
res0: Boolean = true

scala> Dyno.bar
dynatype: $line2.$read.$iw.$iw.Dyno.applyDynamic("bar")()
res1: Boolean = true

scala> Dyno.baz
dynatype: $line2.$read.$iw.$iw.Dyno.applyDynamic("baz")()
error: exception during macro expansion: no dice