simplify 'struct'

tests/struct.js

@@ -0,0 +1,38 @@
+import assert from "node:assert";
+
+import { makeTypeConstructor } from "../lib/meta/type_constructor.js";
+import { Bool, Char, Int } from "../lib/primitives/primitive_types.js";
+import { makeModuleStruct } from "../lib/structures/struct.types.js";
+import { lsType } from "../lib/structures/type_constructors.types.js";
+
+
+const symbolPerson = "Person__22a59ca589b4a7efdbe20b52f380e50f";
+
+const Person = makeTypeConstructor(symbolPerson)(0);
+
+const fields = [
+  {l: "name", r: lsType(_ => Char)},
+  {l: "age", r: Int},
+  {l: "isMale", r: Bool},
+];
+
+const [
+  [, {i: newPerson}],
+  [, {i: getName}],
+  [, {i: getAge}],
+  [, {i: getIsMale}],
+] = makeModuleStruct(Person)(fields);
+
+const expectedName = "billy";
+const expectedAge = 99;
+const expectedIsMale = true;
+
+const billy = newPerson(expectedName)(expectedAge)(expectedIsMale);
+
+const actualName = getName(billy);
+const actualAge = getAge(billy);
+const actualIsMale = getIsMale(billy);
+
+assert.equal(actualName, expectedName);
+assert.equal(actualAge, expectedAge);
+assert.equal(actualIsMale, expectedIsMale);