Language Basics and Boundaries

Gox implements an ES6+ language subset. Declare variables with let / const (recommended); var is also supported — since 0.8.0 it coexists with let / const, following the traditional semantics (function scope, redeclaration allowed, hoisted to the top of the function). See the FAQ.

// Variables and constants
let x = 10
const PI = 3.14

// Arrow functions, closures
const add = (a, b) => a + b
const counter = () => { let n = 0; return () => ++n }
let next = counter()

// class
class Point {
  constructor(x, y) { this.x = x; this.y = y }
  norm() { return Math.hypot(this.x, this.y) }
}
console.log(new Point(3, 4).norm())        // → 5

// Destructuring, rest parameters, default parameters, spread
let [a, b, ...rest] = [1, 2, 3, 4]
function greet(name = "world", ...tags) { return `hi ${name} ${tags}` }
let merged = [...[1, 2], ...[3, 4]]        // [1, 2, 3, 4]
let { host, port } = { host: "127.0.0.1", port: 8080 }

// Template literals, for...of (bindings can be destructured), try/catch
for (const v of [1, 2, 3]) console.log(`v = ${v}`)
for (const [k, v] of [["a", 1]]) console.log(`k = ${k}, v = ${v}`)   // → k = a, v = 1
try {
  throw new Error("boom")
} catch (e) {
  console.log(e.message)                   // → boom
}

// Optional chaining and nullish coalescing
let cfg = { db: { host: "localhost" } }
let host2 = cfg?.db?.host ?? "127.0.0.1"

Language Boundaries (Know These Before You Write, Save Half an Hour of Debugging)

Syntax	Gox's behavior
var	Supported (since 0.8.0): function scope plus hoisting. Day-to-day code should still prefer let / const
import { x as y }	Supported. x is the module’s export name and y is the local binding; import { x } is equivalent to import { x as x }
Date / Intl	Not available. Use Temporal
encodeURI / btoa etc.	Not available. Build what you need with String methods yourself

Note

JSX syntax (<text>...</text>) is also part of the language subset; it is lowered to h(tag, props, ...children) calls at compile time. See the GUI Desktop Apps section for details.