override Stream#take

fix scala/bug#10883

Author: xuwei-k

src/library/scala/collection/immutable/LazyList.scala

@@ -737,6 +737,12 @@ sealed abstract class Stream[+A] extends AbstractSeq[A] with LinearSeq[A] with L
     }
   }
 
+  override def take(n: Int): Stream[A] = {
+    if (n <= 0 || isEmpty) Stream.empty
+    else if (n == 1) new Stream.Cons(head, Stream.empty)
+    else new Stream.Cons(head, tail.take(n - 1))
+  }
+
   /** LazyList specialization of foldLeft which allows GC to collect along the
     * way.
     *

test/junit/scala/collection/immutable/StreamTest.scala

@@ -237,4 +237,15 @@ class StreamTest {
     s2.flatMap { i => (if(i < 5) None else Some(i)): Option[Int] }.headOption
     assertEquals(5, it1.current)
   }
+
+  @Test
+  def t10883: Unit = {
+    var value: Int = -1
+    Stream.iterate(0){ a =>
+      val next = a + 1
+      value = next
+      next
+    }.take(3).toList
+    assertEquals(value, 2)
+  }
 }