Accompaniment

generator/vocabulary.py

@@ -23,8 +23,20 @@ def _load(contents):
   result = {}
   for name, text in contents:
     value = json.loads(text)
-    if value.get('version') != 1 or not value.get('provenance') or not value.get('license'):
+    if value.get('version') != (2 if name == 'accompaniment' else 1) or not value.get('provenance') or not value.get('license'):
       raise ValueError(f'{name}: unsupported or unprovenanced production vocabulary')
+    if name == 'accompaniment':
+      if fractions.Fraction(value['grid']) != fractions.Fraction(1, 2):
+        raise ValueError('accompaniment requires an eighth-note placement grid')
+      for lane in ('electric', 'bass', 'upper'):
+        layer = value['layers'][lane]
+        if not 0 <= layer['attacks'][0] <= layer['attacks'][1] <= 3 or not layer['families']:
+          raise ValueError('invalid accompaniment attack range or duration families')
+        for family in layer['families']:
+          if not value['families'][family] or any(fractions.Fraction(d) <= 0 for d in value['families'][family]):
+            raise ValueError('accompaniment durations must be positive')
+      if not 1 <= value['lane_candidates'] <= 64 or not 1 <= value['measure_candidates'] <= 64:
+        raise ValueError('accompaniment candidate budgets must be 1–64')
     entries = value.get('cells', value.get('patterns', value.get('colors', value.get('transformations', []))))
     if len({v['id'] for v in entries}) != len(entries):
       raise ValueError(f'{name}: duplicate vocabulary ID')