ArrayUtil.removeFirstIf(), removeLastIf(), removeAllIf() predicate-based removal functions

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5533 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/util/ArrayUtil.as

@@ -208,6 +208,45 @@ public class ArrayUtil
         return removeImpl(arr, element, false);
     }
 
+    /**
+     * Removes the first element in the array for which the specified predicate returns true.
+     *
+     * @param pred a Function of the form: function (element :*) :Boolean
+     *
+     * @return true if an element was removed, false otherwise.
+     */
+    public static function removeFirstIf (arr :Array, pred :Function) :Boolean
+    {
+        return removeIfImpl(arr, pred, true);
+    }
+
+    /**
+     * Removes the last element in the array for which the specified predicate returns true.
+     *
+     * @param pred a Function of the form: function (element :*) :Boolean
+     *
+     * @return true if an element was removed, false otherwise.
+     */
+    public static function removeLastIf (arr :Array, pred :Function) :Boolean
+    {
+        arr.reverse();
+        var removed :Boolean = removeFirstIf(arr, pred);
+        arr.reverse();
+        return removed;
+    }
+
+    /**
+     * Removes all elements in the array for which the specified predicate returns true.
+     *
+     * @param pred a Function of the form: function (element :*) :Boolean
+     *
+     * @return true if an element was removed, false otherwise.
+     */
+    public static function removeAllIf (arr :Array, pred :Function) :Boolean
+    {
+        return removeIfImpl(arr, pred, false);
+    }
+
     /**
      * Do the two arrays contain elements that are all equals()?
      */
@@ -249,10 +288,18 @@ public class ArrayUtil
      */
     private static function removeImpl (
         arr :Array, element :Object, firstOnly :Boolean) :Boolean
+    {
+        return removeIfImpl(arr, createEqualsPred(element), firstOnly);
+    }
+
+    /**
+     * Implementation of removeIf methods.
+     */
+    private static function removeIfImpl (arr :Array, pred :Function, firstOnly :Boolean) :Boolean
     {
         var removed :Boolean = false;
         for (var ii :int = 0; ii < arr.length; ii++) {
-            if (Util.equals(arr[ii], element)) {
+            if (pred(arr[ii])) {
                 arr.splice(ii--, 1);
                 if (firstOnly) {
                     return true;
@@ -262,5 +309,12 @@ public class ArrayUtil
         }
         return removed;
     }
+
+    private static function createEqualsPred (element :Object) :Function
+    {
+        return function (other :Object) :Boolean {
+            return Util.equals(other, element);
+        }
+    }
 }
 }