harmonize equality testing and List CONTAINS testing

2 files changed, 6 insertions, 18 deletions

diff --git a/history.txt b/history.txt
index b5f1e6d..a9a711c 100755
--- a/history.txt
+++ b/history.txt
@@ -2023,4 +2023,4 @@ ______
 131204
 ------
 * Threads: handle text comparisons case-insensitive (again)
-
+* Lists: harmonize equality testing and List CONTAINS testing
diff --git a/lists.js b/lists.js
index 2bbcd0b..60cd7e3 100644
--- a/lists.js
+++ b/lists.js
@@ -61,7 +61,7 @@ PushButtonMorph, SyntaxElementMorph, Color, Point, WatcherMorph,
 StringMorph, SpriteMorph, ScrollFrameMorph, CellMorph, ArrowMorph,
 MenuMorph, snapEquals, Morph, isNil, localize, MorphicPreferences*/
 
-modules.lists = '2013-October-08';
+modules.lists = '2013-December-04';
 
 var List;
 var ListWatcherMorph;
@@ -209,30 +209,18 @@ List.prototype.at = function (index) {
 };
 
 List.prototype.contains = function (element) {
-    var num = parseFloat(element);
     if (this.isLinked) {
-        if (this.first === element) {
+        if (snapEquals(this.first, element)) {
             return true;
         }
-        if (!isNaN(num)) {
-            if (parseFloat(this.first) === num) {
-                return true;
-            }
-        }
         if (this.rest instanceof List) {
             return this.rest.contains(element);
         }
-        return false;
     }
     // in case I'm arrayed
-    if (contains(this.contents, element)) {
-        return true;
-    }
-    if (!isNaN(num)) {
-        return (contains(this.contents, num))
-            || contains(this.contents, num.toString());
-    }
-    return false;
+    return this.contents.some(function (any) {
+        return snapEquals(any, element);
+    });
 };
 
 // List conversion: