progress with versioning

lib/versioning/compare.js

@@ -0,0 +1,50 @@
+import { compareDynamic } from "../compare/dynamic.js";
+import { compareSymbols, compareInts } from "../compare/primitives.js";
+import { makeTypeParser } from "../parser/type_parser.js";
+import { newDynamic } from "../primitives/dynamic.js";
+import { makeEnumCompareFn } from "../structures/enum.js";
+import { makeStructCompareFn } from "../structures/struct.js";
+import { Slot, Transformation, Value, Write } from "./value_slot.js";
+
+
+// comparison functions are mutually recursive...
+
+export const compareSlot = makeEnumCompareFn([
+  { l: "new", r: () => compareSymbols },
+  { l: "write", r: () => compareWrite },
+]);
+
+export const compareWrite = makeStructCompareFn([
+  { l: "slot", r: () => compareSlot },
+  { l: "value", r: () => compareValue },
+  { l: "depth", r: () => compareInts },
+]);
+
+export const compareTransformation = makeStructCompareFn([
+  { l: "input", r: () => compareValue },
+  { l: "fn", r: () => compareValue },
+  { l: "output", r: () => compareDynamic },
+]);
+
+export const compareValue = makeEnumCompareFn([
+  { l: "literal", r: () => compareDynamic },
+  { l: "read", r: () => compareWrite },
+  { l: "transform", r: () => compareTransformation },
+]);
+
+const mkType = makeTypeParser({
+  extraPrimitives: [
+    ["Value", Value],
+    ["Slot" , Slot ],
+    ["Write", Write],
+    ["Transformation", Transformation],
+  ],
+});
+
+export const ModuleVersioningCompare = [
+  // comparison
+  ["compareSlot" , newDynamic(compareSlot )(mkType("Slot -> Slot -> Ordering"))],
+  ["compareValue", newDynamic(compareValue)(mkType("Value -> Value -> Ordering"))],
+  ["compareWrite", newDynamic(compareWrite)(mkType("Write -> Write -> Ordering"))],
+  ["compareTransformation", newDynamic(compareTransformation)(mkType("Transformation -> Transformation -> Ordering"))],
+];