case classes implement trait scala.CaseClass

6 files changed, 81 insertions, 7 deletions

diff --git a/sources/meta/scalac/ast/Tree.java b/sources/meta/scalac/ast/Tree.java
index 8df7d2221d..bb59069140 100644
--- a/sources/meta/scalac/ast/Tree.java
+++ b/sources/meta/scalac/ast/Tree.java
@@ -276,7 +276,7 @@ public class Tree {
 
         n_Switch.
             setDescription("Switch").
-            setRange(Phase.TRANSMATCH, Phase.END).
+            setRange(Phase.REFCHECK, Phase.END).
             addField(t_TermTree, "test").
             addField(t_ints, "tags").
             addField(t_TermTrees, "bodies").
diff --git a/sources/scala/CaseClass.scala b/sources/scala/CaseClass.scala
new file mode 100644
index 0000000000..2e6306138b
--- /dev/null
+++ b/sources/scala/CaseClass.scala
@@ -0,0 +1,26 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2002-2003, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |                                         **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+** $Id$
+\*                                                                      */
+
+package scala;
+
+/** defines an access function for instances of case classes.
+ *
+ *  @author  Burak Emir
+ */
+trait CaseClass {
+
+  /** for a case class A(x1,...,xk), returns x_i for 1<= i <= k, null otherwise
+  */
+  def selectElement(n:int):Any = null;
+
+  /** for a case class A(x1,...,xk), returns k
+  */
+  def numberOfElements(): int = 0;
+
+}
diff --git a/sources/scala/tools/scalac/ast/parser/Parser.scala b/sources/scala/tools/scalac/ast/parser/Parser.scala
index 09e07f7312..6f4df2bd00 100644
--- a/sources/scala/tools/scalac/ast/parser/Parser.scala
+++ b/sources/scala/tools/scalac/ast/parser/Parser.scala
@@ -257,6 +257,10 @@ class Parser(unit: Unit) {
     make.Apply(
       pos, scalaDot(pos, Names.ScalaObject.toTypeName()), Tree.EMPTY_ARRAY);
 
+  def caseClassConstr(pos: int): Tree =
+    make.Apply(
+      pos, scalaDot(pos, Names.CaseClass.toTypeName()), Tree.EMPTY_ARRAY);
+
   /** Create tree for for-comprehension <for (enums) do body> or
   *   <for (enums) yield body> where mapName and flatmapName are chosen
   *  corresponding to whether this is a for-do or a for-yield.
@@ -1859,7 +1863,7 @@ class Parser(unit: Unit) {
 		        paramClauseOpt()));
     } while (s.token == COMMA);
     val thistpe = simpleTypedOpt();
-    val template = classTemplate();
+    val template = classTemplate( mods );
     val ts = new myTreeList();
 	lhs foreach { case Tuple4(p, n, tp, vp) =>
 		ts.append(
@@ -1879,7 +1883,7 @@ class Parser(unit: Unit) {
 	  lhs.append(Pair(s.pos, ident()));
     } while (s.token == COMMA);
 	val thistpe = simpleTypedOpt();
-    val template = classTemplate();
+    val template = classTemplate( mods );
     val ts = new myTreeList();
 	lhs foreach { case Pair(p, n) =>
 		ts.append(
@@ -1892,7 +1896,7 @@ class Parser(unit: Unit) {
 
   /** ClassTemplate ::= [`extends' Constr] {`with' Constr} [TemplateBody]
    */
-  def classTemplate(): Tree$Template = {
+  def classTemplate( mods:int ): Tree$Template = {
     val pos = s.pos;
     val parents = new myTreeList();
     if (s.token == EXTENDS) {
@@ -1902,6 +1906,9 @@ class Parser(unit: Unit) {
       parents.append(scalaAnyRefConstr(pos));
     }
     parents.append(scalaObjectConstr(pos));
+    if( (mods & Modifiers.CASE) != 0 ) {
+          parents.append(caseClassConstr(pos));
+    }
     if (s.token == WITH) {
       s.nextToken();
       template(parents)
diff --git a/sources/scala/tools/scalac/typechecker/DeSugarize.scala b/sources/scala/tools/scalac/typechecker/DeSugarize.scala
index ae21fac622..11cd558573 100644
--- a/sources/scala/tools/scalac/typechecker/DeSugarize.scala
+++ b/sources/scala/tools/scalac/typechecker/DeSugarize.scala
@@ -609,7 +609,7 @@ class DeSugarize(make: TreeFactory, copy: TreeCopier, gen: TreeGen, infer: scala
 	.setSymbol(vparam.symbol())));
   }
 
-  /** add case constructor, defintiions value and access functions.
+  /** add case constructor, definitions value and access functions.
   */
   def addCaseElements(body: Array[Tree], vparams: Array[Tree$ValDef]): Array[Tree] = {
     val stats: TreeList = new TreeList();
diff --git a/sources/scalac/typechecker/RefCheck.java b/sources/scalac/typechecker/RefCheck.java
index a96a21fd0a..455bcd3f15 100644
--- a/sources/scalac/typechecker/RefCheck.java
+++ b/sources/scalac/typechecker/RefCheck.java
@@ -29,8 +29,9 @@ import Tree.*;
  *  It preforms the following transformations.
  *
  *   - Local modules are replaced by variables and classes
- *   - toString, equals, and hashCode methods are added to case classes, unless
- *     they are defined in the class or a baseclass different from java.lang.Object
+ *   - equals, and hashCode, selectElement and toString methods are added to
+ *     case classes, unless they are defined in the class or a baseclass
+ *     different from java.lang.Object
  *   - Calls to case factory methods are replaced by new's.
  *   - Type nodes are replaced by TypeTerm nodes.
  *   - Eliminate constant definitions
@@ -687,6 +688,39 @@ public class RefCheck extends Transformer implements Modifiers, Kinds {
 	return gen.DefDef(toStringSym, body);
     }
 
+    private Tree selectElementMethod( ClassSymbol clazz ) {
+	Symbol seSym = clazz.newMethod( clazz.pos, OVERRIDE, Names.selectElement );
+	Symbol seParam = seSym.newVParam(
+            clazz.pos, 0, Names.n, defs.INT_TYPE());
+        seSym.setInfo(
+            Type.MethodType( new Symbol[]{ seParam }, defs.ANY_TYPE() ));
+	clazz.info().members().enter( seSym );
+	Tree[] fields = caseFields( clazz );
+        Tree body;
+        if( fields.length > 0) {        // switch< n >
+            int tags[] = new int[ fields.length ];
+            int i = 0; while( i < fields.length ) { tags[i] = ++i; };
+            body = gen.Switch( gen.mkLocalRef( clazz.pos, seParam ),
+                               tags,
+                               fields,
+                               gen.mkNullLit( clazz.pos ),
+                               defs.ANY_TYPE() );
+        }
+        else
+            body = gen.mkNullLit( clazz.pos );
+	return gen.DefDef(seSym, body);
+    }
+
+    private Tree numberOfElementsMethod( ClassSymbol clazz ) {
+	Symbol seSym = clazz.newMethod( clazz.pos, OVERRIDE, Names.numberOfElements );
+        seSym.setInfo(
+            Type.MethodType( Symbol.EMPTY_ARRAY, defs.INT_TYPE() ));
+	clazz.info().members().enter( seSym );
+	Tree[] fields = caseFields( clazz );
+	return gen.DefDef(seSym, gen.mkIntLit( clazz.pos, fields.length ));
+    }
+
+
     private Tree equalsMethod(ClassSymbol clazz) {
 	Symbol equalsSym = clazz.newMethod(clazz.pos, OVERRIDE, Names.equals);
 	Symbol equalsParam = equalsSym.newVParam(
@@ -823,6 +857,9 @@ public class RefCheck extends Transformer implements Modifiers, Kinds {
 	    ts.append(equalsMethod(clazz));
 	if (!hasImplementation(clazz, Names.hashCode))
 	    ts.append(hashCodeMethod(clazz));
+
+        ts.append(selectElementMethod(clazz));
+        ts.append(numberOfElementsMethod(clazz));
 	ts.append(tagMethod(clazz));
 	if (ts.length() > 0) {
 	    Tree[] stats1 = new Tree[stats.length + ts.length()];
diff --git a/sources/scalac/util/Names.java b/sources/scalac/util/Names.java
index 87858f395c..619ddf5b07 100644
--- a/sources/scalac/util/Names.java
+++ b/sources/scalac/util/Names.java
@@ -106,6 +106,7 @@ public class Names {
     public static final Name AnyRef = Name.fromString("AnyRef");
     public static final Name Array = Name.fromString("Array");
     public static final Name Byte = Name.fromString("Byte");
+    public static final Name CaseClass = Name.fromString("CaseClass");
     public static final Name Catch = Name.fromString("Catch");
     public static final Name Char = Name.fromString("Char");
     public static final Name Boolean = Name.fromString("Boolean");
@@ -164,9 +165,11 @@ public class Names {
     public static final Name length = Name.fromString("length");
     public static final Name match = Name.fromString("match");
     public static final Name map = Name.fromString("map");
+    public static final Name n = Name.fromString("n");
     public static final Name nobinding = Name.fromString("nobinding");
     public static final Name next = Name.fromString("next");
     public static final Name newArray = Name.fromString("newArray");
+    public static final Name numberOfElements = Name.fromString("numberOfElements");
     public static final Name null_ = Name.fromString("null");
     public static final Name predef = Name.fromString("predef");
     public static final Name print = Name.fromString("print");
@@ -176,6 +179,7 @@ public class Names {
     public static final Name synchronized_ = Name.fromString("synchronized");
     public static final Name eq = Name.fromString("eq");
     public static final Name equals = Name.fromString("equals");
+    public static final Name selectElement = Name.fromString("selectElement");
     public static final Name tail = Name.fromString("tail");
     public static final Name toString = Name.fromString("toString");
     public static final Name that = Name.fromString("that");