Merge branch 'master' of https://github.com/functionaljava/functionaljava

jbgi · jbgi · commit 8be6e3325bac · 2015-11-19T14:05:45.000+01:00
diff --git a/core/src/main/java/fj/data/List.java b/core/src/main/java/fj/data/List.java
@@ -795,7 +795,15 @@ public final A index(final int i) {
    * @return A new list with a length the same, or less than, this list.
    */
   public final List<A> take(final int i) {
-    return i <= 0 || isEmpty() ? List.<A>nil() : cons(head(), tail().take(i - 1));
+    Buffer<A> result = Buffer.empty();
+    List<A> list = this;
+    int index = i;
+    while (index > 0 && list.isNotEmpty()) {
+      result.snoc(list.head());
+      list = list.tail();
+      index--;
+    }
+    return result.toList();
   }
 
   /**
@@ -823,16 +831,19 @@ public final List<A> drop(final int i) {
    * @return A pair of lists split at the given index of this list.
    */
   public final P2<List<A>, List<A>> splitAt(final int i) {
-    P2<List<A>, List<A>> s = p(List.<A>nil(), List.<A>nil());
-
     int c = 0;
+    List<A> first = List.<A>nil();
+    List<A> second = List.nil();
     for (List<A> xs = this; xs.isNotEmpty(); xs = xs.tail()) {
       final A h = xs.head();
-      s = c < i ? s.map1(as -> as.snoc(h)) : s.map2(as1 -> as1.snoc(h));
+      if (c < i) {
+          first = first.cons(h);
+      } else {
+          second = second.cons(h);
+      }
       c++;
     }
-
-    return s;
+    return P.p(first.reverse(), second.reverse());
   }
 
   /**
diff --git a/core/src/main/java/fj/data/Stream.java b/core/src/main/java/fj/data/Stream.java
@@ -18,10 +18,7 @@
 import fj.Ordering;
 import fj.function.Effect1;
 
-import java.util.AbstractCollection;
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.NoSuchElementException;
+import java.util.*;
 
 import static fj.Bottom.error;
 import static fj.Function.compose;
@@ -232,7 +229,7 @@ public Stream<A> _1() {
 
       public Stream<A> prefix(final A x, final Stream<A> xs) {
         return xs.isEmpty() ? xs : cons(x, p(cons(xs.head(), () -> prefix(a, xs.tail()._1()))));
-     }
+      }
     });
   }
 
@@ -553,6 +550,14 @@ public final Stream<A> interleave(final Stream<A> as) {
     return isEmpty() ? as : as.isEmpty() ? this : cons(head(), () -> as.interleave(tail()._1()));
   }
 
+  public static <A> Stream<A> enumerationStream(Enumeration<A> e) {
+    if (e.hasMoreElements()) {
+      return Stream.cons(e.nextElement(), () -> enumerationStream(e));
+    } else {
+      return Stream.nil();
+    }
+  }
+
   /**
    * Sort this stream according to the given ordering.
    *
