progress and some refactoring

structures/versioned.js

@@ -0,0 +1,63 @@
+import { makeGeneric } from "../generics/generics.js";
+import { Bool } from "../primitives/types.js";
+import { makeTypeConstructor } from "../type_constructor.js";
+import { getEq } from "../typeclasses/eq.js";
+import { eqDictType } from "../typeclasses/eq_type.js";
+import { fnType, setType } from "./types.js";
+
+const symbolVersioned = Symbol("Versioned");
+export const versionedType = makeTypeConstructor(symbolVersioned, 1);
+
+
+export const constructor = parents => value  => {
+  return { parents, alternatives };
+}
+
+const constructorType = makeGeneric(a =>
+  fnType
+    (a)
+    (setType(versionedType(a)))
+);
+
+// const getValue = v => 
+
+const eq = eqDict => vA => vB => {
+  return getEq(eqDict)(vA.value,vB.value) // compare values
+      && (vA.parents.symmetricDifference(vB.parents).size === 0); // compare parents
+}
+
+// EqDict a -> Versioned a -> Versioned a -> Bool
+const eqVersioned = makeGeneric(a =>
+  fnType
+    (eqDictType(a))
+    (fnType
+      (versionedType(a))
+      (fnType
+        (versionedType(a))
+        (Bool)
+      )
+    )
+);
+
+// EqDict a -> Versioned a -> Versioned a -> Versioned a -> Versioned a
+export const mergeThreeWay = eqDict => vLCA => vA => vB => {
+  if (eq(eqDict)(vLCA)(vA)) {
+    return vB; // vB successor of vA
+  }
+  if (eq(eqDict)(vLCA)(vB)) {
+    return vA; // vA successor of vB
+  }
+  return mergeConcurrent(vLCA)(vA)(vB);
+};
+
+export const mergePrimitives = vA => vB => vA.union(vB);
+
+// Versioned a -> Versioned a -> Versioned a
+export const mergePrimitivesType = makeGeneric(a => 
+  fnType
+    (versionedType(a))
+    (fnType
+      (versionedType(a))
+      (versionedType(a))
+    )
+);