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Diffstat (limited to 'test/pending/run/reify_simpleinterpreter.scala')
-rw-r--r-- | test/pending/run/reify_simpleinterpreter.scala | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/test/pending/run/reify_simpleinterpreter.scala b/test/pending/run/reify_simpleinterpreter.scala new file mode 100644 index 0000000000..b39f5583bb --- /dev/null +++ b/test/pending/run/reify_simpleinterpreter.scala @@ -0,0 +1,82 @@ +import scala.tools.nsc.reporters._ +import scala.tools.nsc.Settings +import reflect.runtime.Mirror.ToolBox + +object Test extends App { + val code = scala.reflect.Code.lift{ + case class M[A](value: A) { + def bind[B](k: A => M[B]): M[B] = k(value) + def map[B](f: A => B): M[B] = bind(x => unitM(f(x))) + def flatMap[B](f: A => M[B]): M[B] = bind(f) + } + + def unitM[A](a: A): M[A] = M(a) + + def showM(m: M[Value]): String = m.value.toString(); + + type Name = String + + trait Term; + case class Var(x: Name) extends Term + case class Con(n: Int) extends Term + case class Add(l: Term, r: Term) extends Term + case class Lam(x: Name, body: Term) extends Term + case class App(fun: Term, arg: Term) extends Term + + trait Value + case object Wrong extends Value { + override def toString() = "wrong" + } + case class Num(n: Int) extends Value { + override def toString() = n.toString() + } + case class Fun(f: Value => M[Value]) extends Value { + override def toString() = "<function>" + } + + type Environment = List[Pair[Name, Value]] + + def lookup(x: Name, e: Environment): M[Value] = e match { + case List() => unitM(Wrong) + case Pair(y, b) :: e1 => if (x == y) unitM(b) else lookup(x, e1) + } + + def add(a: Value, b: Value): M[Value] = Pair(a, b) match { + case Pair(Num(m), Num(n)) => unitM(Num(m + n)) + case _ => unitM(Wrong) + } + + def apply(a: Value, b: Value): M[Value] = a match { + case Fun(k) => k(b) + case _ => unitM(Wrong) + } + + def interp(t: Term, e: Environment): M[Value] = t match { + case Var(x) => lookup(x, e) + case Con(n) => unitM(Num(n)) + case Add(l, r) => for (a <- interp(l, e); + b <- interp(r, e); + c <- add(a, b)) + yield c + case Lam(x, t) => unitM(Fun(a => interp(t, Pair(x, a) :: e))) + case App(f, t) => for (a <- interp(f, e); + b <- interp(t, e); + c <- apply(a, b)) + yield c + } + + def test(t: Term): String = + showM(interp(t, List())) + + val term0 = App(Lam("x", Add(Var("x"), Var("x"))), Add(Con(10), Con(11))) + val term1 = App(Con(1), Con(2)) + + println(test(term0)) + println(test(term1)) + }; + + val reporter = new ConsoleReporter(new Settings) + val toolbox = new ToolBox(reporter) + val ttree = toolbox.typeCheck(code.tree) + toolbox.runExpr(ttree) +} |