From 8538ee68045753c7157a7fcddeb508a0779542d4 Mon Sep 17 00:00:00 2001
From: dfsek <dfsek@protonmail.com>
Date: Mon, 15 Aug 2022 10:33:25 -0700
Subject: [PATCH] add simple do notation for monadic binding

---
 .../terra/addons/manifest/api/monad/Do.java   | 64 +++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 common/addons/manifest-addon-loader/src/main/java/com/dfsek/terra/addons/manifest/api/monad/Do.java

diff --git a/common/addons/manifest-addon-loader/src/main/java/com/dfsek/terra/addons/manifest/api/monad/Do.java b/common/addons/manifest-addon-loader/src/main/java/com/dfsek/terra/addons/manifest/api/monad/Do.java
new file mode 100644
index 000000000..3ab297e2d
--- /dev/null
+++ b/common/addons/manifest-addon-loader/src/main/java/com/dfsek/terra/addons/manifest/api/monad/Do.java
@@ -0,0 +1,64 @@
+package com.dfsek.terra.addons.manifest.api.monad;
+
+import io.vavr.Function1;
+import io.vavr.Function2;
+import io.vavr.Function3;
+import io.vavr.Function4;
+
+import com.dfsek.terra.api.util.function.monad.Monad;
+
+
+public final class Do {
+    private Do() {
+    
+    }
+    
+    public static <T, M extends Monad<?, M>> Monad<T, M> with(Monad<T, M> monad) {
+        return monad;
+    }
+    
+    public static <T, U, M extends Monad<?, M>> Monad<U, M> with(Monad<T, M> monad,
+                                                                 Function1<T, Monad<U, M>> bind) {
+        return monad
+                .bind(bind);
+    }
+    
+    public static <T, U, V, M extends Monad<?, M>> Monad<V, M> with(Monad<T, M> monad,
+                                                                    Function1<T, Monad<U, M>> bind,
+                                                                    Function2<T, U, Monad<V, M>> bind2) {
+        return monad
+                .bind(t -> monad
+                        .bind(bind)
+                        .bind(bind2.apply(t)));
+    }
+    
+    public static <T, U, V, W, M extends Monad<?, M>> Monad<W, M> with(Monad<T, M> monad,
+                                                                       Function1<T, Monad<U, M>> bind,
+                                                                       Function2<T, U, Monad<V, M>> bind2,
+                                                                       Function3<T, U, V, Monad<W, M>> bind3) {
+        return monad
+                .bind(t -> monad
+                        .bind(bind)
+                        .bind(u -> bind2.apply(t)
+                                        .andThen(vmMonad -> vmMonad
+                                                .bind(bind3.apply(t, u)))
+                                        .apply(u)));
+    }
+    
+    public static <T, U, V, W, X, M extends Monad<?, M>> Monad<X, M> with(Monad<T, M> monad,
+                                                                          Function1<T, Monad<U, M>> bind,
+                                                                          Function2<T, U, Monad<V, M>> bind2,
+                                                                          Function3<T, U, V, Monad<W, M>> bind3,
+                                                                          Function4<T, U, V, W, Monad<X, M>> bind4) {
+        return monad
+                .bind(t -> monad
+                        .bind(bind)
+                        .bind(u -> bind2.apply(t)
+                                        .andThen(vmMonad -> vmMonad
+                                                .bind(v -> bind3.apply(t, u)
+                                                                .andThen(wmMonad -> wmMonad
+                                                                        .bind(bind4.apply(t, u, v)))
+                                                                .apply(v)))
+                                        .apply(u)));
+    }
+}