specialFunctions

website/src/playground/files/index.ts

@@ -9,6 +9,7 @@ export const orderedFiles = [
   '/tutorial/revertOnCatch.ts',
   '/tutorial/strings.ts',
   '/tutorial/binaryTree.ts',
+  '/tutorial/specialFunctions.ts',
 ];
 
 export const defaultFiles: Record<string, string | nil> = {

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

@@ -0,0 +1,39 @@
+// We're still working on the standard library for ValueScript, but lots of
+// common things are covered.
+//
+// This program solves https://projecteuler.net/problem=16 by converting 2^1000
+// to a string, separating the digits with `Array.from`, converting those digit
+// strings to numbers by using `Number` as a function and `.map`, and then doing
+// the sum using `.reduce`.
+
+export default function main() {
+  return Array
+    .from(`${2n ** 1000n}`)
+    .map(Number)
+    .reduce((a, b) => a + b);
+
+  // ie 2^1000 = 1071508... (302 digits)
+  //    sum    = 1 + 0 + 7 + 1 + 5 + 0 + 8 + ... = 1366
+}
+
+// There are two types of these special functions which aren't written in
+// ValueScript:
+//
+// 1. Built-in language functionality (like those above)
+// 2. Foreign functions for platform functionality (like fetch, console.log)
+//
+// So far, we only have type 1, there are no type 2 functions. Yet.
+//
+// Platform access is extremely important, but getting the language itself right
+// is more foundational and is still being actively developed.
+
+function alternateSolution() {
+  const digits = `${2n ** 1000n}`;
+  let sum = 0;
+
+  for (let d of digits) {
+    sum += Number(d);
+  }
+
+  return sum;
+}