finish maybe

common/api/src/main/java/com/dfsek/terra/api/util/generic/data/types/Maybe.java

@@ -4,6 +4,7 @@ import com.dfsek.terra.api.util.generic.control.Monad;
 
 import java.util.Optional;
 import java.util.function.Function;
+import java.util.function.Supplier;
 
 
 public interface Maybe<T> extends Monad<T, Maybe<?>> {
@@ -17,14 +18,18 @@ public interface Maybe<T> extends Monad<T, Maybe<?>> {
 
     Optional<T> toOptional();
 
+    <L> Either<L, T> toEither(L l);
+    T get(Supplier<T> def);
+
+    default T get(T def) {
+        return get(() -> def);
+    }
+
+    default <T1> Maybe<T1> overwrite(Maybe<T1> m) {
+        return bind(ignore -> m);
+    }
+
     static <T1> Maybe<T1> just(T1 t) {
-        return new Just<>(t);
-    }
-
-    static <T1> Maybe<T1> nothing() {
-        return new Nothing<>();
-    }
-
         record Just<T>(T value) implements Maybe<T> {
 
             @Override
@@ -32,11 +37,25 @@ public interface Maybe<T> extends Monad<T, Maybe<?>> {
                 return Optional.of(value);
             }
 
+            @Override
+            public <L> Either<L, T> toEither(L l) {
+                return Either.right(value);
+            }
+
+            @Override
+            public T get(Supplier<T> def) {
+                return value;
+            }
+
             @Override
             public <T2> Maybe<T2> bind(Function<T, Monad<T2, Maybe<?>>> map) {
                 return (Maybe<T2>) map.apply(value);
             }
         }
+        return new Just<>(t);
+    }
+
+    static <T1> Maybe<T1> nothing() {
         record Nothing<T>() implements Maybe<T> {
 
             @Override
@@ -48,5 +67,17 @@ public interface Maybe<T> extends Monad<T, Maybe<?>> {
             public Optional<T> toOptional() {
                 return Optional.empty();
             }
+
+            @Override
+            public <L> Either<L, T> toEither(L l) {
+                return Either.left(l);
+            }
+
+            @Override
+            public T get(Supplier<T> def) {
+                return def.get();
+            }
+        }
+        return new Nothing<>();
     }
 }