From e55510607031aaf7b8473453f83c44a26c9b97e0 Mon Sep 17 00:00:00 2001
From: Adriaan Moors <adriaan.moors@typesafe.com>
Date: Mon, 9 Dec 2013 11:06:22 -0800
Subject: Remove docs/examples; they reside at scala/scala-dist

---
 docs/examples/monads/errorInterpreter.scala | 86 -----------------------------
 1 file changed, 86 deletions(-)
 delete mode 100644 docs/examples/monads/errorInterpreter.scala

(limited to 'docs/examples/monads/errorInterpreter.scala')

diff --git a/docs/examples/monads/errorInterpreter.scala b/docs/examples/monads/errorInterpreter.scala
deleted file mode 100644
index d3cc45627d..0000000000
--- a/docs/examples/monads/errorInterpreter.scala
+++ /dev/null
@@ -1,86 +0,0 @@
-object errorInterpreter {
-
-  trait M[A] {
-    def show: String
-    def bind[B](k: A => M[B]): M[B]
-    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]          =  new Suc(a)
-  def errorM[A](msg: String): M[A]  =  new Err(msg)
-
-  def showM(m: M[Value]): String = m.show
-
-  class Suc[A](x: A) extends M[A] {
-    def bind[B](k: A => M[B]): M[B] = k(x)
-    def show: String = "Success: " + x
-  }
-  class Err[A](msg: String) extends M[A] {
-    def bind[B](k: A => M[B]): M[B] = new Err(msg)
-    def show: String = "Error: " + msg
-  }
-
-  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() => errorM("unbound variable: " + x);
-    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 _ => errorM("should be numbers: " + a + "," + b)
-  }
-
-  def apply(a: Value, b: Value): M[Value] = a match {
-    case Fun(k) => k(b)
-    case _ => errorM("should be function: " + a)
-  }
-
-  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))
-
-  def main(args: Array[String]) = {
-    System.out.println(test(term0))
-    System.out.println(test(term1))
-  }
-}
-
-- 
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