Fix Stream.length to use an iterative approach here as the previous implementation (toList().length()) took very long (several seconds) even for some 10000 elements.

magro · magro · commit 02580b12edeb · 2011-09-22T00:32:46.000+02:00
diff --git a/core/src/main/java/fj/data/Stream.java b/core/src/main/java/fj/data/Stream.java
@@ -1239,7 +1239,15 @@ public final A last() {
    * @return The length of this stream.
    */
   public final int length() {
-    return toList().length();
+    // we're using an iterative approach here as the previous implementation (toList().length()) took
+    // very long even for some 10000 elements.
+    Stream<A> xs = this;
+    int i = 0;
+    while (!xs.isEmpty()) {
+      xs = xs.tail()._1();
+      i += 1;
+    }
+    return i;
   }
 
   /**
