patrn

patrn brings the declarative functionality of SuperCollider's Pattern system to Clojure whilst requiring the programmer to learn as little as possible library specific vocabulary.

Philosophy

• Declarative - say what will occur not how it will happen.
• Grammatical - learn a simple grammar not a stack of new nouns and verbs.
• Idiomatic - uses Clojure's Lazy Sequences to represent streams of values and encourages use of core libraries sequence manipulation functions rather than presenting more vocabulary to the user.
• Simple - pattern/event definition and playback decomplected.
• Easy - get started quickly when using Overtone, Pink, MIDI, or OSC messages to render output.

Usage

Getting started

Playing back a patrn with Overtone

Create a new Clojure project at the command line with lein:

lein new plinky-plonky

Add the following to :dependancies vector in plinky-plonky/project.clj:

[overtone "0.9.1"]
[patrn "0.0.1-SNAPSHOT]

And plop something this in your src/plinky_plonky/core.clj file:

(ns plinky-plonky.core
  (:require [patrn.core :as p]
            [patrn.overtone :refer [play])
  (:use [overtone.live]))

(def a-flock-of-sea-gulls 
  (p/bind :degree   (take 8 (partition-all 3 1 (range -6 12 2)))
          :duration (repeat [0.2 0.2 0.1])
          :length   (repeat 0.45)))

(play a-flock-of-sea-gulls)

And run the expressions.

SuperCollider -> patrn Analogues

patrn's patrn->seq function and Clojure's core library do away with the need for a large vocabulary of sequence generating functions as provided by SuperCollider's Pattern classes. Clojure provides analogues to many of SuperCollider's pattern definition functions in its core library.

SuperCollider	Clojure & patrn	patrn->seq
Pseq([1, 2, 3])	[1 2 3]	'(1 2 3)
Pseq([1, 2, 3], 4)	(repeat 4 [1 2 3])	'(1 2 3 1 2 3 1 2 3 1 2 3)
Pseq([1, 2, 3], inf)	(cycle [1 2 3])	'(1 2 3 1 2 3 1 2 3 ...
Pser([1, 2, 3], 4)	(take 4 (cycle [1 2 3]))	'(1 2 3 1)
Pseries(1, 3, 9)	(take 9 (range 9 100 3))	`'(1 4 7 10 13 16 19 22 25 28)``
(-6,2..12)	(range -6 12 2)	'(-6 -4 -2 0 2 4 6 8 10 12)
Pslide((-6,2..12), 8, 3, 1, 0)	(take 8 (partition-all 3 1 (range -16 12 2)))	'(-6 -4 -2 -4 -2 0 -2 0 2...)

How to run the tests

The project uses Midje for testing. lein midje will run all tests.