Utility to create stream from Slime array

2 files changed, 47 insertions, 0 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/slime/SlimeStream.java b/vespajlib/src/main/java/com/yahoo/slime/SlimeStream.java
new file mode 100644
index 00000000000..a6008294a72
--- /dev/null
+++ b/vespajlib/src/main/java/com/yahoo/slime/SlimeStream.java
@@ -0,0 +1,21 @@
+package com.yahoo.slime;
+
+import java.util.function.Function;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public final class SlimeStream {
+    private SlimeStream() {}
+
+    /**
+     * Create a stream from a Slime {@link Inspector} pointing to an array.
+     * @param array the array inspector
+     * @param mapper the function mapping to Stream elements
+     * @return A Stream of array elements
+     */
+    public static <T> Stream<T> fromArray(Inspector array, Function<Inspector, T> mapper) {
+        return IntStream.range(0, array.entries())
+                .mapToObj(array::entry)
+                .map(mapper);
+    }
+}
diff --git a/vespajlib/src/test/java/com/yahoo/slime/SlimeStreamTest.java b/vespajlib/src/test/java/com/yahoo/slime/SlimeStreamTest.java
new file mode 100644
index 00000000000..116551cea59
--- /dev/null
+++ b/vespajlib/src/test/java/com/yahoo/slime/SlimeStreamTest.java
@@ -0,0 +1,26 @@
+package com.yahoo.slime;
+
+import org.junit.Test;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.junit.Assert.assertEquals;
+
+public class SlimeStreamTest {
+    @Test
+    public void test_empty_array() {
+        var inspector = new Slime().setArray();
+        var items = SlimeStream.fromArray(inspector, Inspector::asString).collect(Collectors.toList());
+        assertEquals(List.of(), items);
+    }
+
+    @Test
+    public void test_some_elements() {
+        var inspector = new Slime().setArray();
+        inspector.addString("foo");
+        inspector.addString("bar");
+        var items = SlimeStream.fromArray(inspector, Inspector::asString).collect(Collectors.toList());
+        assertEquals(List.of("foo", "bar"), items);
+    }
+}