read-dependencies now correctly recorded (i think)

scripts/versioning2.js

@@ -1,99 +1,130 @@
 import { pretty } from "../util/pretty.js";
-import { inspect } from "node:util";
+import { deepEqual } from "../util/util.js";
 
 // UUID -> Computation<a> -> Slot<a>
 const newSlot = uuid => computation => ({
   overwrites: uuid,
   computation,
   // depth: 1,
-  // [inspect.custom]: (depth, options, inspect) => options.stylize(`newSlot(${inspect(uuid)})(${inspect(computation)})`, 'special'),
 });
 
 // a -> Computation<a>
 const newValue = val => ({
   kind: "value",
   out: val,
-  // [inspect.custom]: (depth, options, inspect) => options.stylize(`newValue(${val})`, 'special'),
 });
 
-const id = x => x;
-
 // Slot<a> -> Computation<a>
 const read = slot => ({
-  kind: "transformation",
-  in: slot,
-  fn: {
-    kind: "value",
-    out: id,
-  },
+  kind: "read",
+  slot,
   out: slot.computation.out,
-  // [inspect.custom]: (depth, options, inspect) => options.stylize(`read(${inspect(slot)})`, 'special'),
 });
 
 // Computation<a> -> Computation<a -> b> -> Computation<b>
 const transform = input => fn => {
-  // console.log("transform...", "input:", pretty(input), "fn:", pretty(fn));
   const output = fn.out(input.out);
   if (input.kind === "value") {
-    // our input had no read dependency, thus likewise our output does not:
+    // optimization: sandwich everything together
     return {
       kind: "value",
       out: output,
     };
   }
   else {
-    // console.log("transforming the transformation...");
     return {
       kind: "transformation",
-      in: input.in,
-      // transform the transformation:
-      fn: transform(input.fn)(newValue(origFn => {
-        const descr = `${fn.out.name} ∘ ${origFn.name}`;
-        return { [descr]: x => fn.out(origFn(x)) }[descr];
-      })),
+      in: input,
+      fn,
       out: output,
     };
   }
 };
 
-const counterOne = newSlot(Symbol('counter'))(newValue(1));
+const verifyComputation = (computation, indent=0) => {
+  const printIndent = (...args) => {
+    console.log(" ".repeat(indent*2), ...args);
+  }
+  const compare = (a,b, kind) => {
+    if (typeof a === 'function' && typeof b === 'function') {
+      printIndent("cannot compare functions", `(${kind})`);
+    }
+    else if (deepEqual(a, b)) {
+      printIndent(`ok (${kind})`);
+    }
+    else {
+      printIndent(`bad (${kind})`);
+    }
+  }
+  if (computation.kind === "value") {
+    compare(1, 1, "value");
+  }
+  else if (computation.kind === "read") {
+    compare(computation.out, computation.slot.computation.out, "read");
+  }
+  else if (computation.kind === "transformation") {
+    compare(computation.fn.out(computation.in.out),
+      computation.out, "transformation");
     
-const valueOne = read(counterOne);
+    verifyComputation(computation.in, indent+1);
+    verifyComputation(computation.fn, indent+1);
+  }
+}
+
+const getReadDependencies = computation => {
+  if (computation.kind === "value") {
+    return new Set();
+  }
+  else if (computation.kind === "read") {
+    return new Set([computation.slot]);
+  }
+  else if (computation.kind === "transformation") {
+    return new Set([
+      ...getReadDependencies(computation.in),
+      ...getReadDependencies(computation.fn),
+    ]);
+  }
+}
 
-console.log(pretty({valueOne}));
 
 const inc = x => x + 1;
 
-const onePlusOne = transform(valueOne)(newValue(inc));
+// const counterOne = newSlot(Symbol('counter'))(newValue(1));
+// const valueOne = read(counterOne);
+// console.log(pretty({valueOne}));
+// const onePlusOne = transform(valueOne)(newValue(inc));
+// console.log(pretty({onePlusOne}));
+// const onePlusOnePlusOne = transform(onePlusOne)(newValue(inc));
+// console.log(pretty({onePlusOnePlusOne}));
 
-console.log(pretty({onePlusOne}));
+// verifyComputation(valueOne);
+// verifyComputation(onePlusOne);
+// verifyComputation(onePlusOnePlusOne);
 
-const onePlusOnePlusOne = transform(onePlusOne)(newValue(inc));
 
-console.log(pretty({onePlusOnePlusOne}));
+const priceSlot = newSlot(Symbol('price'))(newValue(20.66));
+const taxSlot   = newSlot(Symbol('tax'))(newValue(4.34));
+
+console.log(pretty({price: priceSlot}));
+
+const computeTotal = tax => {
+  const addTax = price => price + tax;
+  return addTax;
+};
+
+const total =
+  transform(read(priceSlot))(
+    transform(read(taxSlot))(
+      newValue(computeTotal)));
+
+console.log(pretty({total}))
+
+const totalPlusOne = transform(total)(newValue(inc));
+
+console.log(pretty({totalPlusOne}));
+
+verifyComputation(totalPlusOne);
 
 
 
-// const price = newSlot(Symbol('price'))(newValue(20.66));
-// const tax   = newSlot(Symbol('tax'))(newValue(4.34));
-
-// console.log(pretty({price}));
-
-// const total =
-//   transform(read(price))(
-//     transform(read(tax))(
-//       newValue(tax => price => price + tax)));
-
-// console.log(pretty({total}))
-
-// const totalPlusOne = transform(total)(newValue(x => x + 1));
-
-// console.log(pretty({totalPlusOne}));
-
-
-
-// const getReadDependencies = computation => new Set([
-//   ...(computation.kind === "value" ? [] : [computation.in, ...getReadDependencies(computation.fn)]),
-// ]);
-
-// console.log("getReadDependencies(total):", getReadDependencies(total));
+console.log("getReadDependencies(totalPlusOne):", getReadDependencies(totalPlusOne));