Faster rich comparator as sugested in ticket #38.

1 files changed, 27 insertions, 25 deletions

diff --git a/src/library/scala/runtime/Comparator.java b/src/library/scala/runtime/Comparator.java
index 705bf30d5c..9b25100e70 100644
--- a/src/library/scala/runtime/Comparator.java
+++ b/src/library/scala/runtime/Comparator.java
@@ -11,13 +11,15 @@
 
 package scala.runtime;
 
-/**
- *  @author  Gilles Dubochet
- *  @author  Martin Odersky
- *  @version 1.2 */
+/** An object (static class) providing a correct notion of equality in
+  * the general case, in particular with boxed values.
+  * @author  Gilles Dubochet
+  * @author  Martin Odersky
+  * @contributor Stepan Koltsov
+  * @version 1.2 */
 public class Comparator {
 
-    private static int CHAR = 0, BYTE = 1, SHORT = 2, INT = 3, LONG = 4, FLOAT = 5, DOUBLE = 6, OTHER = 7;
+    private static final int CHAR = 0, BYTE = 1, SHORT = 2, INT = 3, LONG = 4, FLOAT = 5, DOUBLE = 6, OTHER = 7;
 
     private static int typeCode(Object a) {
         if (a instanceof Integer) return INT;
@@ -31,21 +33,18 @@ public class Comparator {
     }
 
     /** A rich implementation of the equals method that overrides the default
-     *  equals because Java's boxed primitives are utterly broken. This equals
-     *  is inserted instead of a normal equals by the Scala compiler (in the
-     *  ICode phase, method <code>genEqEqPrimitive</code>) only when either
-     *  side of the comparison is a subclass of <code>AnyVal</code>, of
-     *  <code>java.lang.Number</code>, of <code>java.lang.Character</code> or
-     *  is exactly <code>Any</code> or <code>AnyRef</code>, but when both sides
-     *  have different types. */
+	  * equals because Java's boxed primitives are utterly broken. This equals
+      * is inserted instead of a normal equals by the Scala compiler (in the
+      * ICode phase, method <code>genEqEqPrimitive</code>) only when either
+      * side of the comparison is a subclass of <code>AnyVal</code>, of
+      * <code>java.lang.Number</code>, of <code>java.lang.Character</code> or
+      * is exactly <code>Any</code> or <code>AnyRef</code>. */
     public static boolean equals(Object a, Object b) {
-        if (a == null)
-            return b == null;
-        else if (b == null)
-            return false;
+        if (a == null || b == null)
+            return a == b;
         else if (a.equals(b))
             return true;
-        else {
+        else if (a instanceof Number || a instanceof Character || b instanceof Number || b instanceof Character) {
             int acode = typeCode(a);
             int bcode = typeCode(b);
             int maxcode = (acode < bcode) ? bcode : acode;
@@ -53,23 +52,26 @@ public class Comparator {
                 int aa = (acode == CHAR) ? ((Character) a).charValue() : ((Number) a).intValue();
                 int bb = (bcode == CHAR) ? ((Character) b).charValue() : ((Number) b).intValue();
                 return aa == bb;
-            } else if (maxcode <= LONG) {
+            }
+			else if (maxcode <= LONG) {
                 long aa = (acode == CHAR) ? ((Character) a).charValue() : ((Number) a).longValue();
                 long bb = (bcode == CHAR) ? ((Character) b).charValue() : ((Number) b).longValue();
                 return aa == bb;
-            } else if (maxcode <= FLOAT) {
+            }
+			else if (maxcode <= FLOAT) {
                 float aa = (acode == CHAR) ? ((Character) a).charValue() : ((Number) a).floatValue();
                 float bb = (bcode == CHAR) ? ((Character) b).charValue() : ((Number) b).floatValue();
                 return aa == bb;
-            } else if (maxcode <= DOUBLE) {
+            }
+			else if (maxcode <= DOUBLE) {
                 double aa = (acode == CHAR) ? ((Character) a).charValue() : ((Number) a).doubleValue();
                 double bb = (bcode == CHAR) ? ((Character) b).charValue() : ((Number) b).doubleValue();
                 return aa == bb;
-            } else if (acode != OTHER) {
-                return b.equals(a);
-            } else {
-                return a == b;
             }
-        }
+			else
+                return b.equals(a);
+		}
+		else
+			return false;
     }
 }