tutorial/typeScriptFeatures.ts

inputs/passing/enum.ts

@@ -1,7 +1,7 @@
 //! test_output(10)
 
-import Numbers from "./helpers/Numbers.ts";
+import Num from "./helpers/Num.ts";
 
 export default function () {
-  return Numbers.One + Numbers.Two + Numbers.Three + Numbers.Four;
+  return Num.One + Num.Two + Num.Three + Num.Four;
 }

inputs/passing/helpers/Numbers.ts → inputs/passing/helpers/Num.ts

@@ -1,9 +1,9 @@
-enum Numbers {
+enum Num {
   Zero,
   One,
   Two,
   Three,
   Four,
 }
 
-export default Numbers;
+export default Num;

website/src/playground/files/index.ts

@@ -14,6 +14,7 @@ export const orderedFiles = [
   "/tutorial/structuralComparison.ts",
   "/tutorial/binaryTree.ts",
   "/tutorial/specialFunctions.ts",
+  "/tutorial/typeScriptFeatures.ts",
   "/tutorial/treeShaking.ts",
 ];
 

website/src/playground/files/root/tutorial/typeScriptFeatures.ts

@@ -0,0 +1,75 @@
+// Sometimes TypeScript features generate code. ValueScript supports that too.
+
+export default function () {
+  const bigFruit = biggerFruit(Fruit.Lemon, Fruit.Mango);
+  const point = new Point(3, 4);
+
+  return {
+    bigFruit: {
+      raw: bigFruit,
+      display: Fruit[bigFruit],
+      note: isCitrus(bigFruit) ? "citrus" : "not citrus",
+    },
+    pointDist: point.dist(),
+  };
+}
+
+// Enums don't exist in JavaScript
+enum Fruit {
+  Apple,
+  Banana,
+  Orange,
+  Grape,
+  Mango,
+  Pineapple,
+  Watermelon,
+  Lemon,
+}
+
+class Point {
+  constructor(
+    // By specifying public here, these parameters are automatically initialized
+    // as fields
+    public x: number,
+    public y: number,
+  ) {}
+
+  dist() {
+    return Math.sqrt(this.x ** 2 + this.y ** 2);
+  }
+}
+
+function biggerFruit(left: Fruit, right: Fruit): Fruit {
+  const order = [
+    Fruit.Grape,
+    Fruit.Lemon,
+    Fruit.Banana,
+    Fruit.Orange,
+    Fruit.Apple,
+    Fruit.Mango,
+    Fruit.Pineapple,
+    Fruit.Watermelon,
+  ];
+
+  return order.indexOf(left) > order.indexOf(right) ? left : right;
+}
+
+function isCitrus(fruit: Fruit): boolean {
+  switch (fruit) {
+    case Fruit.Apple:
+    case Fruit.Banana:
+    case Fruit.Grape:
+    case Fruit.Mango:
+    case Fruit.Pineapple:
+    case Fruit.Watermelon:
+      return false;
+
+    case Fruit.Orange:
+    case Fruit.Lemon:
+      return true;
+  }
+
+  // TypeScript knows this is unreachable, so it doesn't complain that we're
+  // failing to return a boolean. If you comment out one of the cases, it'll
+  // emit an error.
+}