- Added Course-2002-11.scala

2 files changed, 307 insertions, 0 deletions

diff --git a/test/files/run/Course-2002-11.check b/test/files/run/Course-2002-11.check
new file mode 100644
index 0000000000..526d7ea790
--- /dev/null
+++ b/test/files/run/Course-2002-11.check
@@ -0,0 +1,11 @@
+
+(    '(1 2 3)) = (1 2 3)
+(car '(1 2 3)) = 1
+(cdr '(1 2 3)) = (2 3)
+(null? '(2 3)) = 0
+(null?    '()) = 1
+
+faculty(10) = 3628800
+faculty(10) = 3628800
+foobar = ("a" "bc" "def" "z")
+
diff --git a/test/files/run/Course-2002-11.scala b/test/files/run/Course-2002-11.scala
new file mode 100644
index 0000000000..46d86c17d6
--- /dev/null
+++ b/test/files/run/Course-2002-11.scala
@@ -0,0 +1,296 @@
+//############################################################################
+// Programmation IV - 2002 - Week 11
+//############################################################################
+// $Id$
+
+module Lisp {
+
+  trait Data {
+    def elemsToString(): String = toString();
+  }
+  case class CONS(car: Data, cdr: Data) extends Data {
+    override def toString() = "(" + elemsToString() + ")";
+    override def elemsToString() = car.toString() + (cdr match {
+      case NIL() => ""
+      case _     => " " + cdr.elemsToString();
+    })
+  }
+  case class NIL() extends Data { // !!! use case module
+    override def toString() = "()";
+  }
+  case class SYM(name: String) extends Data {
+    override def toString() = name;
+  }
+  case class NUM(x: Int) extends Data {
+    override def toString() = x.toString();
+  }
+  case class STR(x: String) extends Data {
+    override def toString() = "\"" + x + "\"";
+  }
+  case class FUN(f: List[Data] => Data) extends Data {
+    override def toString() = "<fn>";
+  }
+
+  def list(): Data =
+    NIL();
+  def list(x0: Data): Data =
+    CONS(x0, NIL());
+  def list(x0: Data, x1: Data): Data =
+    CONS(x0, list(x1));
+  def list(x0: Data, x1: Data, x2: Data): Data =
+    CONS(x0, list(x1, x2));
+  def list(x0: Data, x1: Data, x2: Data, x3: Data): Data =
+    CONS(x0, list(x1, x2, x3));
+  def list(x0: Data, x1: Data, x2: Data, x3: Data, x4: Data): Data =
+    CONS(x0, list(x1, x2, x3, x4));
+  def list(x0: Data, x1: Data, x2: Data, x3: Data, x4: Data, x5: Data): Data =
+    CONS(x0, list(x1, x2, x3, x4, x5));
+  def list(x0: Data, x1: Data, x2: Data, x3: Data, x4: Data, x5: Data,
+   x6: Data): Data =
+    CONS(x0, list(x1, x2, x3, x4, x5, x6));
+  def list(x0: Data, x1: Data, x2: Data, x3: Data, x4: Data, x5: Data,
+   x6: Data, x7: Data): Data =
+    CONS(x0, list(x1, x2, x3, x4, x5, x6, x7));
+  def list(x0: Data, x1: Data, x2: Data, x3: Data, x4: Data, x5: Data,
+   x6: Data, x7: Data, x8: Data): Data =
+    CONS(x0, list(x1, x2, x3, x4, x5, x6, x7, x8));
+  def list(x0: Data, x1: Data, x2: Data, x3: Data, x4: Data, x5: Data,
+   x6: Data, x7: Data, x8: Data, x9: Data): Data =
+    CONS(x0, list(x1, x2, x3, x4, x5, x6, x7, x8, x9));
+
+  var curexp: Data = null;
+  var trace: Boolean = False;
+  var indent: Int = 0;
+
+  def lispError[a](msg: String): a =
+    error("error: " + msg + "\n" + curexp);
+
+  trait Environment {
+    def lookup(n: String): Data;
+    def extendRec(name: String, expr: Environment => Data) =
+      new Environment {
+        def lookup(n: String): Data =
+          if (n == name) expr(this) else Environment.this.lookup(n);
+      }
+    def extend(name: String, v: Data) = extendRec(name, (env1 => v));
+  }
+  val EmptyEnvironment = new Environment {
+    def lookup(n: String): Data = lispError("undefined: " + n);
+  }
+
+  def toList(x: Data): List[Data] = x match {
+    case NIL() => List()
+    case CONS(y, ys) => y :: toList(ys)
+    case _ => lispError("malformed list: " + x);
+  }
+
+  def toBoolean(x: Data) = x match {
+    case NUM(0) => False
+    case _ => True
+  }
+
+  def normalize(x: Data): Data = x match {
+    case CONS(SYM("def"),
+           CONS(CONS(SYM(name), args), CONS(body, CONS(expr, NIL())))) =>
+      normalize(list(SYM("def"),
+        SYM(name), list(SYM("lambda"), args, body), expr))
+    case CONS(SYM("cond"), CONS(CONS(SYM("else"), CONS(expr, NIL())),NIL())) =>
+      normalize(expr)
+    case CONS(SYM("cond"), CONS(CONS(test, CONS(expr, NIL())), rest)) =>
+      normalize(list(SYM("if"), test, expr, CONS(SYM("cond"), rest)))
+    case CONS(h, t) => CONS(normalize(h), normalize(t))
+    case _ => x
+  }
+
+  def eval(x: Data, env: Environment): Data = {
+    val prevexp = curexp;
+    curexp = x;
+    if (trace) {
+      for (val x <- range(1, indent)) do System.out.print(" ");
+      System.out.println("===> " + x);
+      indent = indent + 1;
+    }
+    val result = eval1(x, env);
+    if (trace) {
+      indent = indent - 1;
+      for (val x <- range(1, indent)) do System.out.print(" ");
+      System.out.println("<=== " + result);
+    }
+    curexp = prevexp;
+    result
+  }
+
+  def eval1(x: Data, env: Environment): Data = x match {
+    case SYM(name) =>
+      env lookup name
+    case CONS(SYM("def"), CONS(SYM(name), CONS(y, CONS(z, NIL())))) =>
+      eval(z, env.extendRec(name, (env1 => eval(y, env1))))
+    case CONS(SYM("val"), CONS(SYM(name), CONS(y, CONS(z, NIL())))) =>
+      eval(z, env.extend(name, eval(y, env)))
+    case CONS(SYM("lambda"), CONS(params, CONS(y, NIL()))) =>
+      mkLambda(params, y, env)
+    case CONS(SYM("if"), CONS(c, CONS(t, CONS(e, NIL())))) =>
+      if (toBoolean(eval(c, env))) eval(t, env) else eval(e, env)
+    case CONS(SYM("quote"), CONS(x, NIL())) =>
+      x
+    case CONS(y, xs) =>
+      apply(eval(y, env), toList(xs) map (x => eval(x, env)))
+    case NUM(_) => x
+    case STR(_) => x
+    case FUN(_) => x
+    case _ =>
+      lispError("illegal term")
+    }
+
+  def apply(fn: Data, args: List[Data]): Data = fn match {
+    case FUN(f) => f(args);
+    case _ => lispError("application of non-function: " + fn);
+  }
+
+  def mkLambda(params: Data, expr: Data, env: Environment): Data = {
+
+    def extendEnv(env: Environment,
+                  ps: List[String], args: List[Data]): Environment =
+      Pair(ps, args) match {
+        case Pair(List(), List()) =>
+          env
+        case Pair(p :: ps1, arg :: args1) =>
+          extendEnv(env.extend(p, arg), ps1, args1)
+        case _ =>
+          lispError("wrong number of arguments")
+      }
+
+    val ps: List[String] = toList(params) map {
+      case SYM(name) => name
+      case _ => error("illegal parameter list");
+    }
+
+    FUN(args => eval(expr, extendEnv(env, ps, args)))
+  }
+
+  val globalEnv = EmptyEnvironment
+    .extend("=",FUN({
+      case List(NUM(arg1),NUM(arg2)) => NUM(if(arg1 == arg2) 1 else 0)
+      case List(STR(arg1),STR(arg2)) => NUM(if(arg1 == arg2) 1 else 0)}))
+    .extend("+", FUN({
+      case List(NUM(arg1),NUM(arg2)) => NUM(arg1 + arg2)
+      case List(STR(arg1),STR(arg2)) => STR(arg1 + arg2)}))
+    .extend("-", FUN({
+      case List(NUM(arg1),NUM(arg2)) => NUM(arg1 - arg2)}))
+    .extend("*", FUN({
+      case List(NUM(arg1),NUM(arg2)) => NUM(arg1 * arg2)}))
+    .extend("/", FUN({
+      case List(NUM(arg1),NUM(arg2)) => NUM(arg1 / arg2)}))
+    .extend("car", FUN({
+      case List(CONS(x, xs)) => x}))
+    .extend("cdr", FUN({
+      case List(CONS(x, xs)) => xs}))
+    .extend("null?", FUN({
+      case List(NIL()) => NUM(1)
+      case _ => NUM(0)}))
+    .extend("cons", FUN({
+      case List(x, y) => CONS(x, y)}));
+
+  def evaluate(x: Data): Data = eval(normalize(x), globalEnv);
+  def evaluate(s: String): Data = evaluate(string2lisp(s));
+
+  def string2lisp(s: String): Data = {
+    val it = new LispTokenizer(s);
+    def parseExpr(token: String): Data = {
+      if (token == "(") parseList
+      else if (token == ")") error("unbalanced parentheses")
+      else if ('0' <= token.charAt(0) && token.charAt(0) <= '9')
+        NUM(new java.lang.Integer(token).intValue())
+      else if (token.charAt(0) == '\"' && token.charAt(token.length()-1)=='\"')
+        STR(token.substring(1,token.length() - 1))
+      else SYM(token)
+    }
+    def parseList: Data = {
+      val token = it.next;
+      if (token == ")") NIL() else CONS(parseExpr(token), parseList)
+    }
+    parseExpr(it.next)
+  }
+}
+
+class LispTokenizer(s: String) extends Iterator[String] {
+  private var i = 0;
+  private def isDelimiter(ch: Char) = ch <= ' ' || ch == '(' || ch == ')';
+  def hasNext: Boolean = {
+    while (i < s.length() && s.charAt(i) <= ' ') { i = i + 1 }
+    i < s.length()
+  }
+  def next: String =
+    if (hasNext) {
+      val start = i;
+      var ch = s.charAt(i); i = i + 1;
+      if (ch == '(') "("
+      else if (ch == ')') ")"
+      else {
+        while (i < s.length() && !isDelimiter(s.charAt(i))){ i = i + 1 }
+        s.substring(start, i)
+      }
+    } else error("premature end of string")
+}
+
+//############################################################################
+
+module M0 {
+
+  def test = {
+    import Lisp._;
+    System.out.println();
+    System.out.println("(    '(1 2 3)) = " + evaluate("     (quote(1 2 3))"));
+    System.out.println("(car '(1 2 3)) = " + evaluate("(car (quote(1 2 3)))"));
+    System.out.println("(cdr '(1 2 3)) = " + evaluate("(cdr (quote(1 2 3)))"));
+    System.out.println("(null? '(2 3)) = " + evaluate("(null? (quote(2 3)))"));
+    System.out.println("(null?    '()) = " + evaluate("(null?    (quote()))"));
+    System.out.println();
+    System.out.println("faculty(10) = " + evaluate(
+      "(def (faculty n) " +
+        "(if (= n 0) " +
+          "1 " +
+          "(* n (faculty (- n 1)))) " +
+        "(faculty 10))"));
+    System.out.println("faculty(10) = " + evaluate(
+      "(def (faculty n) " +
+        "(cond " +
+          "((= n 0) 1) " +
+          "(else (* n (faculty (- n 1))))) " +
+        "(faculty 10))"));
+    System.out.println("foobar = " + evaluate(
+      "(def (foo n) " +
+        "(cond " +
+          "((= n 0) \"a\")" +
+          "((= n 1) \"b\")" +
+          "((= (/ n 2) 1) " +
+            "(cond " +
+              "((= n 2) \"c\")" +
+              "(else    \"d\")))" +
+          "(else " +
+            "(def (bar m) " +
+              "(cond " +
+                "((= m 0) \"e\")" +
+                "((= m 1) \"f\")" +
+                "(else    \"z\"))" +
+              "(bar (- n 4)))))" +
+        "(val nil (quote ())" +
+          "(val v1 (foo 0) " +
+            "(val v2 (+ (foo 1) (foo 2)) " +
+              "(val v3 (+ (+ (foo 3) (foo 4)) (foo 5)) " +
+                "(val v4 (foo 6) " +
+                  "(cons v1 (cons v2 (cons v3 (cons v4 nil))))))))))"));
+    System.out.println();
+  }
+}
+
+//############################################################################
+
+module Test {
+  def main(args: Array[String]): Unit = {
+    M0.test;
+    ()
+  }
+}
+
+//############################################################################