rename dir scripts -> examples

examples/enum.js

@@ -0,0 +1,48 @@
+import { makeCompareFn } from "../compare/registry.js";
+import { Int, Unit } from "../primitives/types.js";
+import { unit } from "../primitives/unit.js";
+import { enumType, makeConstructors, makeMatchFn } from "../structures/enum.js";
+import { constructorProduct } from "../structures/product.js";
+import { lsType, prettyT } from "../structures/types.js";
+
+const variants = [
+  constructorProduct("price")(Int),
+  constructorProduct("prices")(lsType(Int)),
+  constructorProduct("not_found")(Unit),
+];
+
+const myEnumType = enumType(variants);
+
+console.log("observe the type that was generated:");
+console.log(" ", prettyT(myEnumType));
+
+const [newPrice, newPrices, newNotFound] = makeConstructors(variants);
+
+const price = newPrice(10);
+const prices = newPrices({ l: [20, 30] });
+const notFound = newNotFound(unit);
+
+console.log("observe the encoding of different variant instances:");
+console.log(" ", price);
+console.log(" ", prices);
+console.log(" ", notFound);
+
+const myEnumToString = x => makeMatchFn(variants)(x)
+  (price => `Price: ${price}`)
+  (prices => `Prices: ${prices.l}`)
+  (() => "Not found!");
+
+console.log("observe the generated match function in action:");
+console.log(" ", myEnumToString(price));
+console.log(" ", myEnumToString(prices));
+console.log(" ", myEnumToString(notFound));
+
+const compareMyEnum = makeCompareFn(myEnumType);
+
+console.log("observe the generated compare function in action:");
+console.log("  smaller ->", compareMyEnum(price)(prices));
+console.log("  bigger  ->", compareMyEnum(prices)(price));
+console.log("  bigger  ->", compareMyEnum(notFound)(price));
+console.log("  equal   ->", compareMyEnum(prices)(prices));
+console.log("  smaller ->", compareMyEnum(newPrice(5))(newPrice(6)));
+console.log("  bigger  ->", compareMyEnum(newPrices({ l: [5, 6] }))(newPrices({ l: [5, 5] })));