Allow binding of parameterised types

1 files changed, 20 insertions, 0 deletions

diff --git a/src/main/java/org/zwobble/couscous/util/Optionals.java b/src/main/java/org/zwobble/couscous/util/Optionals.java
new file mode 100644
index 0000000..979dc5f
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/util/Optionals.java
@@ -0,0 +1,20 @@
+package org.zwobble.couscous.util;
+
+import java.util.Optional;
+import java.util.function.BiFunction;
+
+public class Optionals {
+    private Optionals() {}
+
+    public static <T1, T2, R> Optional<R> flatMap(
+        Optional<T1> first,
+        Optional<T2> second,
+        BiFunction<T1, T2, Optional<R>> function)
+    {
+        if (first.isPresent() && second.isPresent()) {
+            return function.apply(first.get(), second.get());
+        } else {
+            return Optional.empty();
+        }
+    }
+}