start packaging

packages/tonal/voicings.mjs

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+import { Pattern as _Pattern, stack, Hap, reify } from '../core/strudel.mjs';
+import _voicings from 'chord-voicings';
+const { dictionaryVoicing, minTopNoteDiff, lefthand } = _voicings;
+
+const getVoicing = (chord, lastVoicing, range = ['F3', 'A4']) =>
+  dictionaryVoicing({
+    chord,
+    dictionary: lefthand,
+    range,
+    picker: minTopNoteDiff,
+    lastVoicing,
+  });
+
+const Pattern = _Pattern;
+
+Pattern.prototype.fmapNested = function (func) {
+  return new Pattern((span) =>
+    this.query(span)
+      .map((event) =>
+        reify(func(event))
+          .query(span)
+          .map((hap) => new Hap(event.whole, event.part, hap.value, hap.context)),
+      )
+      .flat(),
+  );
+};
+
+Pattern.prototype.voicings = function (range) {
+  let lastVoicing;
+  if (!range?.length) {
+    // allows to pass empty array, if too lazy to specify range
+    range = ['F3', 'A4'];
+  }
+  return this.fmapNested((event) => {
+    lastVoicing = getVoicing(event.value, lastVoicing, range);
+    return stack(...lastVoicing)._withContext(() => ({
+      locations: event.context.locations || [],
+    }));
+  });
+};
+
+Pattern.prototype._rootNotes = function (octave = 2) {
+  return this.fmap((value) => {
+    const [_, root] = value.match(/^([a-gA-G][b#]?).*$/);
+    return root + octave;
+  });
+};
+
+Pattern.prototype.define('voicings', (range, pat) => pat.voicings(range), { composable: true });
+Pattern.prototype.define('rootNotes', (oct, pat) => pat.rootNotes(oct), { composable: true, patternified: true });