Reactive Programming

Gox ships two sets of reactive primitives, both as global functions.

obs: GetX style (Dart GetX semantics)

let count = obs(0)
ever(count, v => console.log("count =", v))   // fires immediately with the current value on subscribe

count.value = 1
count.value = 2
count.value = 2   // value unchanged, no notification

count = 0
count = 1
count = 2

API	Description
obs(value)	Creates an observable value; read/write through .value
computed(fn)	A computed value derived from other observables, recalculated automatically when dependencies change
ever(obs, fn)	Continuous subscription; fires on every change
once(obs, fn)	Fires exactly once, on the next change

signals: SolidJS style (the gx/solid module)

import { createSignal, createEffect, createMemo } from "gx/solid"

const [count, setCount] = createSignal(0)

createEffect(() => console.log("count is", count()))   // runs once immediately
setCount(5)                                            // → count is 5

const doubled = createMemo(() => count() * 2)
setCount(10)
console.log(doubled())                                 // → 20

Note

obs is a global function you can call directly; createSignal and friends need to be imported from "gx/solid" — a Gox built-in module (resolved before the filesystem), and the foundation of the GUI reactive updates covered in the next section.