tonal-dictionary/build/es6.js

Tonal key/value utilities

/**
 * [![npm version](https://img.shields.io/npm/v/tonal-dictionary.svg)](https://www.npmjs.com/package/tonal-dictionary)
 *
 * `tonal-dictionary` contains a dictionary of musical scales and chords
 *
 * This is part of [tonal](https://www.npmjs.com/package/tonal) music theory library.
 *
 * @example
 * // es6
 * import * as Dictionary from "tonal-dictionary"
 * // es5
 * const Dictionary = require("tonal-dictionary")
 *
 * @example
 * Dictionary.chord("Maj7") // => ["1P", "3M", "5P", "7M"]
 *
 * @module Dictionary
 */
import sdata from "./data/scales.json";
import cdata from "./data/chords.json";
import { chroma } from "tonal-pcset";

export var dictionary = function (raw) {
  var keys = Object.keys(raw).sort();
  var data = [];
  var index = [];

  var add = function (name, ivls, chroma) {
    data[name] = ivls;
    index[chroma] = index[chroma] || [];
    index[chroma].push(name);
  };

  keys.forEach(function (key) {
    var ivls = raw[key][0].split(" ");
    var alias = raw[key][1];
    var chr = chroma(ivls);

    add(key, ivls, chr);
    if (alias) { alias.forEach(function (a) { return add(a, ivls, chr); }); }
  });
  var allKeys = Object.keys(data).sort();

  var dict = function (name) { return data[name]; };
  dict.names = function (p) {
    if (typeof p === "string") { return (index[p] || []).slice(); }
    else { return (p === true ? allKeys : keys).slice(); }
  };
  return dict;
};

export var combine = function (a, b) {
  var dict = function (name) { return a(name) || b(name); };
  dict.names = function (p) { return a.names(p).concat(b.names(p)); };
  return dict;
};

/**
 * A dictionary of scales: a function that given a scale name (without tonic)
 * returns an array of intervals
 *
 * @function
 * @param {string} name
 * @return {Array} intervals
 * @example
 * import { scale } from "tonal-dictionary"
 * scale("major") // => ["1P", "2M", ...]
 * scale.names(); // => ["major", ...]
 */
export var scale = dictionary(sdata);

/**
 * A dictionary of chords: a function that given a chord type
 * returns an array of intervals
 *
 * @function
 * @param {string} type
 * @return {Array} intervals
 * @example
 * import { chord } from "tonal-dictionary"
 * chord("Maj7") // => ["1P", "3M", ...]
 * chord.names(); // => ["Maj3", ...]
 */
export var chord = dictionary(cdata);
export var pcset = combine(scale, chord);