JavaScript in code

A program is JavaScript. Most programs only chain pattern methods, but you can use variables, functions, arrays, loops and conditions to build them.

Variables and functions

const names a pattern so you can reuse it. A function can build a pattern from arguments.

const groove = s("bd [~ bd] sd ~, hh*8")
const riff = (root) => n("0 2 4 2").scale(`${root}:minor`)
drums: groove.bank("tr909")
lead: cat(riff("C"), riff("F"), riff("G"), riff("C"))

Double and single quotes

Double quotes (and backticks) are mini-notation: "c3 e3" is a pattern of two notes. Single quotes are a plain string that is not read as mini-notation - useful for names that contain spaces.

n("0 1 2 3").scale('C minor')

Loops and arrays

Ordinary JavaScript can generate patterns. Here an array of degrees is built with a loop and joined into mini-notation:

const steps = []
for (let i = 0; i < 8; i++) steps.push(i % 3 === 0 ? i : "~")
n(steps.join(" ")).scale("A:minor").s("triangle")

Your own methods: register

register(name, fn) adds a method you can chain like the built-in ones. The pattern comes last in the function's arguments.

register('dub', (amount, pat) => pat.delay(amount).delayfeedback(0.6).room(0.3))
note("c3 ~ ~ eb3 ~ ~ g3 ~").s("square").dub(0.5)

The sandbox

Code arrives in shared projects and links, so TuttiDAW never runs it as ordinary page script. Simple programs are read by TuttiDAW's own interpreter; anything else runs in a sealed JavaScript sandbox (QuickJS in WebAssembly) whose only ability is building patterns:

• there is no network, no page, no storage, no timers and no eval;
• import(...) and fetch are not available; external audio is declared with samples(...) and only loaded by the player when you press Play;
• every program has a work budget and a time limit, so an endless loop stops with an error instead of freezing the page.

Determinism

The same code always plays the same notes - on your computer, a collaborator's, in an export:

• Math.random() and the pattern functions rand, ?, |, sometimes and friends are seeded;
• the clock is stopped: Date.now() always returns the same moment;
• every render starts fresh, so state kept in variables does not carry over from one play to the next.

const pick = Math.floor(Math.random() * 4)
n(`<${pick} 2 4 6>`).scale("E:minor")

This program picks the same "random" note every time it is run.

Limits

• a program can be up to 100,000 characters (a /code link up to 20,000);
• a cycle can hold up to 2,048 events in one voice.

A program over a limit reports an error at the code that caused it; the other voices keep playing.