1 files changed, 21 insertions, 0 deletions
diff --git a/src/main/java/moe/nea/pcj/AppendableError.java b/src/main/java/moe/nea/pcj/AppendableError.java
new file mode 100644
index 0000000..6ec48fa
--- /dev/null
+++ b/src/main/java/moe/nea/pcj/AppendableError.java
@@ -0,0 +1,21 @@
+package moe.nea.pcj;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface AppendableError<T extends AppendableError<T>> {
+	/**
+	 * @return an optional Self with getSuppressed containing the argument
+	 */
+	Optional<T> appendError(Object other);
+
+	List<T> getSuppressed();
+
+	static <T> T concatError(T left, T right) {
+		if (left instanceof AppendableError<?> appendable) {
+			var opt = (Optional<T>) appendable.appendError(right);
+			return opt.orElse(left);
+		}
+		return left;
+	}
+}