Jaffle Syntax

This page aims to provide an overview of the Jaffle syntax, for people already familiar with the Strudel language.

If necessary, read the Strudel documentation to understand how to write music with Strudel.

Most of this syntax is used both in the yaml and node editors: when editing a node, you can add a prefix or a suffix to change its behavior.

Yaml basics

Jaffle uses the Yaml syntax. Here is the basic usage:

# I'm a comment
- array:
  - 1
  - 2
- dictionary:
    a: 1
    b: 2
- array of dictionaries:
  - a1: 1
    b1: 2
  - a2: 3
    b2: 4
- inline array: [ 1, 2, 3 ]
- inline dict: { a: 1, b: 2 }
- inline array of dictionaries: [ a: 1, b: 2 ]
- literals:
  - string: hello
  - quoted string: '[ 1, 2, 3 ]'
  - number: 42
  - float: 2.21
  - null value:

Mini-notation

Mini-notation strings are prefixed with _:

Strudel	Jaffle
`note("c@3 eb")`	`- note: _c@3 eb`

Chained functions

Chained functions are array items following the first function, prefixed with .:

Strudel	Jaffle
`note("c@3 eb") .lpf(600) .delay(.5) .gain(2)`	`- note: _c@3 eb - .lpf: 600 - .delay: .5 - .gain: 2`

You can consider that this prefix visually acts as a small indentation character. ;)

Function parameters

Function parameters are defined in an array:

Strudel	Jaffle
`stack( note("c@3 eb"), sound("bd hh sd oh"))`	`- stack: - note: _c@3 eb - sound: _bd hh sd oh`

Note that the yaml root element must also be an array (hence the first -).

Functions without parameters

It is safe to have a yaml attribute without value (just don’t forget the : sign):

Strudel	Jaffle
`note("c@3 eb") .piano() .log()`	`- note: c@3 eb - .piano: - .log:`

List of chained functions

When functions chains follow each other, they are still on the same level:

Strudel	Jaffle
`stack( note("c@3 eb") .lpf(600) .delay(.5), sound("bd hh sd oh") .gain(0.5) .slow(2))`	`- stack: - note: _c@3 eb - .lpf: 600 - .delay: .5 - sound: _bd hh sd oh - .gain: 0.5 - .slow: 2`

In this case it is suggested to split function chains with a blank line.

Data serialization

To pass structured data in a parameter, you must add ^ after the attribute name:

Strudel Jaffle

samples({
  bd: [
    'bd/BT0AADA.wav',
    'bd/BT0AAD0.wav'],
  sd: [
    'sd/rytm-01-classic.wav',
    'sd/rytm-00-hard.wav'],
  hh: [
    'hh27/000_hh27closedhh.wav',
    'hh/000_hh3closedhh.wav'],
}, 'github:tidalcycles/Dirt-Samples/master/');
s("<bd:0 bd:1>,~ <sd:0 sd:1>,[hh:0 hh:1]*2")

- samples^:
  - bd:
    - bd/BT0AADA.wav
    - bd/BT0AAD0.wav
    sd:
    - sd/rytm-01-classic.wav
    - sd/rytm-00-hard.wav
    hh:
    - hh27/000_hh27closedhh.wav
    - hh/000_hh3closedhh.wav
  - github:tidalcycles/Dirt-Samples/master/
- s: _<bd:0 bd:1>,~ <sd:0 sd:1>,[hh:0 hh:1]*2

To serialize data on a specific argument, add its index next to ^, starting from 1 (ie. foo^1:).

Signals

Keywords without parenthesis like signals are written with a capital on the first letter:

Strudel	Jaffle
`saw .range(50, 80) .segment(24) .note()`	`- Saw: - .range: [ 50, 80 ] - .segment: 24 - .note:`

Expressions

To put an expression in a parameter, prepend it by the = sign:

Strudel	Jaffle
`"c3 [eb3,g3]" .add(1/3) .note()`	`- _c3 [eb3,g3] - .add: =1/3 - .note:`

Such expressions are limited to simple mathematics (+, -, *, /, **).

Functions in parameters

To pass a function in a parameter such as in accumulation modifiers, use set (here with an inline dictionnary):

Strudel	Jaffle
`note("c3 eb3 g3 a3") .sometimes(x=>x.gain(8))`	`- note: _c3 eb3 g3 a3 - .sometimes: [ set: , .gain: 8 ]`

If necessary, additional parameters can be passed in the set value:

Strudel	Jaffle
`"<0 [2 4]>" .echoWith(4, 1/8, (p,n) => p.add(n*2)) .scale('C minor') .note()`	`- _<0 [2 4]> - .echoWith: [ 4, =1/8, set: n, .add: =n*2 ] - .scale: C minor - .note:`

More parameters could be added using an array (ie. set: [ n, m ]).

Using variables

Variables can be defined using the $ prefix and accessed in expressions (=):

Strudel Jaffle

const melody =
  note("c@3 eb")
    .lpf(600)
    .delay(.5)
const drums =
  sound("bd hh sd oh")
    .gain(0.5)
stack(
    melody,
    drums
      .slow(2))

- $melody:
  - note: _c@3 eb
  - .lpf: 600
  - .delay: .5
- $drums:
  - sound: _bd hh sd oh
  - .gain: 0.5
- stack:
  - =melody
  - =drums
  - .slow: 2