tonal-key

<!doctype html> <html lang="en"> <head> <title>Code coverage report for index.js</title> <meta charset="utf-8" /> <link rel="stylesheet" href="prettify.css" /> <link rel="stylesheet" href="base.css" /> <meta name="viewport" content="width=device-width, initial-scale=1"> <style type='text/css'> .coverage-summary .sorter { background-image: url(sort-arrow-sprite.png); } </style> </head> <body> <div class='wrapper'> <div class='pad1'> <h1> <a href="index.html">All files</a> index.js </h1> <div class='clearfix'> <div class='fl pad1y space-right2'> 90.91% Statements 80/88 </div> <div class='fl pad1y space-right2'> 76.47% Branches 26/34 </div> <div class='fl pad1y space-right2'> 95% Functions 19/20 </div> <div class='fl pad1y space-right2'> 100% Lines 66/66 </div> </div> </div> <div class='status-line high'></div> <pre><table class="coverage"> <tr><td class="line-count quiet">1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299</td><td class="line-coverage quiet">                                                  1x     1x 1x   1x 1x 1x   22x                             1x 3x                     10x   1x 2x 2x 10x 2x     1x                     1x 20x 20x 19x 19x 19x 19x 19x 19x 19x 19x 19x     32x                                         1x                             1x                 1x 2x 2x 2x 2x 14x                             1x 2x 2x 2x                                                                       10x 8x 8x 8x 56x 8x 9x                               1x                             1x                         1x 1x 1x 7x                                       1x 3x 3x 3x 3x 3x 3x                         1x 25x 25x 25x 22x    </td><td class="text"><pre class="prettyprint lang-js">/** * [![npm version](https://img.shields.io/npm/v/tonal-key.svg?style=flat-square)](https://www.npmjs.com/package/tonal-key) * [![tonal](https://img.shields.io/badge/tonal-key-yellow.svg?style=flat-square)](https://www.npmjs.com/browse/keyword/tonal) * * `tonal-key` is a collection of functions to query about tonal keys. * * This is part of [tonal](https://www.npmjs.com/package/tonal) music theory library. * * @example * // es6 * import * as Key from "tonal-key" * // es5 * const Key = require("tonal-key") * * @example * Key.scale("E mixolydian") // => [ "E", "F#", "G#", "A", "B", "C#", "D" ] * Key.relative("minor", "C major") // => "A minor" * * @module Key */ import { rotate, range } from "tonal-array"; import { tokenize as split, altToAcc } from "tonal-note"; import { trFifths, fifths, interval, transpose } from "tonal-distance"; import { fromDegree, decimal } from "tonal-roman-numeral";   const MODES = "major dorian phrygian lydian mixolydian minor locrian ionian aeolian".split( " " ); const NUMS = [0, 1, 2, 3, 4, 5, 6, 0, 5]; const NOTES = "C D E F G A B".split(" ");   const TRIADS = ["", "m", "m", "", "", "m", "dim"]; const SEVENTHS = "Maj7 m7 m7 Maj7 7 m7 m7b5".split(" "); const FIFTHS = [0, 2, 4, -1, 1, 3, 5, 0, 3];   const modenum = mode => NUMS[MODES.indexOf(mode)];   /** * Get a list of valid mode names. The list of modes will be always in * increasing order (ionian to locrian) * * @function * @param {Boolean} alias - true to get aliases names * @return {Array} an array of strings * @example * Key.modes() // => [ "ionian", "dorian", "phrygian", "lydian", * // "mixolydian", "aeolian", "locrian" ] * Key.modes(true) // => [ "ionian", "dorian", "phrygian", "lydian", * // "mixolydian", "aeolian", "locrian", "major", "minor" ] */ export const modeNames = aliases => aliases === true ? MODES.slice() : MODES.slice(0, 7);   /** * Create a major key from alterations * * @function * @param {Integer} alt - the alteration number (positive sharps, negative flats) * @return {Key} the key object * @example * Key.fromAlter(2) // => "D major" */ export const fromAlter = i => trFifths("C", i) + " major";   export const names = (alt = 4) => { alt = Math.abs(alt); const result = []; for (let i = -alt; i <= alt; i++) result.push(fromAlter(i)); return result; };   const NO_KEY = Object.freeze({ name: null, tonic: null, mode: null, modenum: null, intervals: [], scale: [], alt: null, acc: null });   const properties = name => { const p = tokenize(name); if (p[0] === null) return NO_KEY; const k = { tonic: p[0], mode: p[1] }; k.name = k.tonic + " " + k.mode; k.modenum = modenum(k.mode); const cs = rotate(k.modenum, NOTES); k.alt = fifths("C", k.tonic) - FIFTHS[MODES.indexOf(k.mode)]; k.acc = altToAcc(k.alt); k.intervals = cs.map(interval(cs[0])); k.scale = k.intervals.map(transpose(k.tonic)); return Object.freeze(k); };   const memo = (fn, cache = {}) => str => cache[str] || (cache[str] = fn(str));   /** * Return the a key properties object with the following information: * * - name {string}: name * - tonic {string}: key tonic * - mode {string}: key mode * - modenum {Number}: mode number (0 major, 1 dorian, ...) * - intervals {Array}: the scale intervals * - scale {Array}: the scale notes * - acc {string}: accidentals of the key signature * - alt {Number}: alteration number (a numeric representation of accidentals) * * @function * @param {string} name - the key name * @return {Object} the key properties object or null if not a valid key * * @example * Key.props("C3 dorian") // => { tonic: "C", mode: "dorian", ... } */ export const props = memo(properties);   /** * Get scale of a key * * @function * @param {string|Object} key * @return {Array} the key scale * * @example * Key.scale("A major") // => [ "A", "B", "C#", "D", "E", "F#", "G#" ] * Key.scale("Bb minor") // => [ "Bb", "C", "Db", "Eb", "F", "Gb", "Ab" ] * Key.scale("C dorian") // => [ "C", "D", "Eb", "F", "G", "A", "Bb" ] * Key.scale("E mixolydian") // => [ "E", "F#", "G#", "A", "B", "C#", "D" ] */ export const scale = str => props(str).scale;   /** * Get a list of key scale degrees in roman numerals * @param {string} keyName * @return {Array} * @example * Key.degrees("C major") => ["I", "ii", "iii", "IV", "V", "vi", "vii"] */ export const degrees = str => { const p = props(str); Iif (p.name === null) return []; const chords = rotate(p.modenum, SEVENTHS); return chords.map((chord, i) => { return fromDegree(i + 1, chord[0] !== "m"); }); };   /** * Get a list of the altered notes of a given Key. The notes will be in * the same order than in the key signature. * * @function * @param {string} key - the key name * @return {Array} * * @example * Key.alteredNotes("Eb major") // => [ "Bb", "Eb", "Ab" ] */ export const alteredNotes = name => { const alt = props(name).alt; Iif (alt === null) return null; return alt === 0 ? [] : alt > 0 ? range(1, alt).map(trFifths("B")) : range(-1, alt).map(trFifths("F")); };   /** * Get a lead-sheet symbols for a given key name * * This function is currified (so can be partially applied) * * From http://openmusictheory.com/triads.html * * A lead-sheet symbol begins with a capital letter (and, if necessary, * an accidental) denoting the root of the chord. * That letter is followed by information about a chord’s quality: * * - major triad: no quality symbol is added * - minor triad: lower-case “m” * - diminished triad: lower-case “dim” or a degree sign “°” * - augmented triad: lower-case “aug” or a plus sign “+” * * @param {Array<string>} symbols - an array of symbols in major scale order * @param {string} keyName - the name of the key you want the symbols for * @param {Array<string>} [degrees] - the list of degrees. By default from 1 to 7 in ascending order * @return {function} * @see Key.chords * @see Key.triads * * @example * const chords = Key.leadsheetSymbols(["M", "m", "m", "M", "7", "m", "dim"]) * chords("D dorian") //=> ["Dm", "Em", "FM", "G7", "Am", "Bdim", "CM"] * chords("D dorian", ['ii', 'V']) //=> [Em", "G7"] */ export function leadsheetSymbols(symbols, keyName, degrees) { if (arguments.length === 1) return (n, d) => leadsheetSymbols(symbols, n, d); const p = props(keyName); Iif (!p.name) return []; const names = rotate(p.modenum, symbols); const chords = p.scale.map((tonic, i) => tonic + names[i]); if (!degrees) return chords; return degrees.map(decimal).map(n => chords[n - 1]); }   /** * Get key seventh chords * * @function * @param {string} name - the key name * @param {Array<number|string>} [degrees] - can be numbers or roman numerals * @return {Array<string>} seventh chord names * * @example * Key.chords("A major") // => ["AMaj7", "Bm7", "C#m7", "DMaj7", ..,] * Key.chords("A major", ['I', 'IV', 'V']) // => ["AMaj7", "DMaj7", "E7"] * Key.chords("A major", [5, 4, 1]) // => ["E7", "DMaj7", AMaj7"] */ export const chords = leadsheetSymbols(SEVENTHS);   /** * Get key triads * * @function * @param {string} name - the key name * @param {Array<string|number>} [degrees] * @return {Array<string>} triad names * * @example * Key.triads("A major") // => ["AM", "Bm", "C#m", "DM", "E7", "F#m", "G#mb5"] * Key.triads("A major", ['I', 'IV', 'V']) // => ["AMaj7", "DMaj7", "E7"] * Key.triads("A major", [1, 4, 5]) // => ["AMaj7", "DMaj7", "E7"] */ export const triads = leadsheetSymbols(TRIADS);   /** * Get secondary dominant key chords * * @function * @param {string} name - the key name * @return {Array} * * @example * Key.secDomChords("A major") // => ["E7", "F#7", ...] */   export const secDomChords = name => { const p = props(name); Iif (!p.name) return []; return p.scale.map(t => transpose(t, "P5") + "7"); };   /** * Get relative of a key. Two keys are relative when the have the same * key signature (for example C major and A minor) * * It can be partially applied. * * @function * @param {string} mode - the relative destination * @param {string} key - the key source * * @example * Key.relative("dorian", "B major") // => "C# dorian" * // partial application * var minor = Key.relative("minor") * minor("C major") // => "A minor" * minor("E major") // => "C# minor" */ export const relative = (mode, key) => { Iif (arguments.length === 1) return key => relative(mode, key); const num = modenum(mode.toLowerCase()); Iif (num === undefined) return null; const k = props(key); Iif (k.name === null) return null; return trFifths(k.tonic, FIFTHS[num] - FIFTHS[k.modenum]) + " " + mode; };   /** * Split the key name into its components (pitch class tonic and mode name) * * @function * @param {string} name * @return {Array} an array in the form [tonic, key] * * @example * Key.tokenize("C major") // => ["C", "major"] */ export const tokenize = name => { const p = split(name); p[3] = p[3].toLowerCase(); if (p[0] === "" || MODES.indexOf(p[3]) === -1) return [null, null]; return [p[0] + p[1], p[3]]; };  </pre></td></tr> </table></pre> <div class='push'></div> </div> <div class='footer quiet pad2 space-top1 center small'> Code coverage generated by <a href="https://istanbul.js.org/" target="_blank">istanbul</a> at Tue Feb 26 2019 22:00:58 GMT+0100 (CET) </div> </div> <script src="prettify.js"></script> <script> window.onload = function () { if (typeof prettyPrint === 'function') { prettyPrint(); } }; </script> <script src="sorter.js"></script> </body> </html>