Parsing shorthand with Ramda

ramda-music.js

import { pipe, split, map, match, head, applySpec, join, addIndex, last, add } from 'ramda';
import { Time } from 'tone';

const indexedMap = addIndex(map);
const calcDuration = pipe(split('@'), last);

const parseShorthand = pipe(
  split(','),
  indexedMap(
    applySpec({
      name: pipe(split('@'), head, match(/[A-G](b|#)?/), head),
      octave: pipe(split('@'), head, match(/[0-9]/), join(''), parseInt),
      duration: calcDuration,
      time: (note, index, array) => array.slice(0,index).map(pipe(calcDuration, Time)).reduce(add, 0)
    })
  ),
);

parseShorthand('C4@8n,D4@16n,Eb4@16n,F4@4n,G4@8n,A4@16n,B4@16n,C5@4n').forEach(console.log);