1 files changed, 44 insertions, 0 deletions
diff --git a/src/main/java/gregtech/api/util/GTStreamUtil.java b/src/main/java/gregtech/api/util/GTStreamUtil.java
new file mode 100644
index 0000000000..4b71fe5ee8
--- /dev/null
+++ b/src/main/java/gregtech/api/util/GTStreamUtil.java
@@ -0,0 +1,44 @@
+package gregtech.api.util;
+
+import java.util.Arrays;
+import java.util.function.Supplier;
+import java.util.stream.Stream;
+
+import javax.annotation.Nullable;
+import javax.annotation.ParametersAreNonnullByDefault;
+
+@ParametersAreNonnullByDefault
+@MethodsReturnNonnullByDefault
+public final class GTStreamUtil {
+
+    /**
+     * Backport of {@link Stream#ofNullable}.
+     */
+    public static <T> Stream<T> ofNullable(@Nullable T value) {
+        return value == null ? Stream.empty() : Stream.of(value);
+    }
+
+    /**
+     * Returns a sequential ordered {@code Stream} whose elements are the specified values,
+     * if {@code condition} is true, otherwise returns an empty {@code Stream}.
+     *
+     * @param <T>    the type of stream elements
+     * @param values the elements of the new stream
+     * @return the new stream
+     */
+    public static <T> Stream<T> ofConditional(boolean condition, T[] values) {
+        return condition ? Arrays.stream(values) : Stream.empty();
+    }
+
+    /**
+     * Returns a sequential {@code Stream} containing a single element, which will be lazily evaluated from supplier.
+     *
+     * @param <T>      the type of stream elements
+     * @param supplier the supplier for single stream element
+     * @return the new stream
+     */
+    public static <T> Stream<T> ofSupplier(Supplier<T> supplier) {
+        return Stream.generate(supplier)
+            .limit(1);
+    }
+}