Merge pull request #2054 from float3/realize-cache-altered-degrees

Key the realization cache on the altered degrees

Author: mscuthbert

music21/scale/intervalNetwork.py

@@ -80,7 +80,8 @@ def __str__(self) -> str:
 
 
 type CacheKey = tuple[
-    int|Terminus, str, str|None, str|None, bool, bool|None]
+    int|Terminus, str, str|None, str|None, bool, bool|None,
+    tuple[tuple[int, Direction, int, int|float], ...]]
 
 class AlteredDegree(t.TypedDict):
     '''
@@ -1421,6 +1422,7 @@ def _getCacheKey(
         *,
         includeFirst: bool,
         reverse: bool|None = None,  # only meaningful for descending
+        alteredDegrees: AlteredDegrees|None = None,
     ) -> CacheKey:
         '''
         Return key for caching based on critical components.
@@ -1434,12 +1436,23 @@ def _getCacheKey(
             maxKey = maxPitch.nameWithOctave
         else:
             maxKey = None
+
+        # an interval's generic number and semitones say what it is, and are
+        # cheaper to read than its name
+        alteredKey: tuple[tuple[int, Direction, int, int|float], ...] = ()
+        if alteredDegrees:
+            alteredKey = tuple([(degree,
+                                 spec['direction'],
+                                 spec['interval'].generic.directed,
+                                 spec['interval'].semitones)
+                                for degree, spec in alteredDegrees.items()])
         return (nodeObj.id,
                 pitchReference.nameWithOctave,
                 minKey,
                 maxKey,
                 includeFirst,
                 reverse,
+                alteredKey,
                 )
 
     def realizeAscending(
@@ -1513,7 +1526,8 @@ def realizeAscending(
                                    pitchReference,
                                    minPitch,
                                    maxPitch,
-                                   includeFirst=False)
+                                   includeFirst=False,
+                                   alteredDegrees=alteredDegrees)
             if ck in self._ascendingCache:
                 return self._ascendingCache[ck]
         else:
@@ -1720,6 +1734,7 @@ def realizeDescending(
                                    maxPitch=maxPitchObj,
                                    includeFirst=includeFirst,
                                    reverse=reverse,
+                                   alteredDegrees=alteredDegrees,
                                    )
             if ck in self._descendingCache:
                 return self._descendingCache[ck]

music21/scale/test_scale_main.py

@@ -320,6 +320,11 @@ def testDeriveHarmonicMinor(self):
         sc = scale.HarmonicMinorScale()
         self.assertEqual(sc.derive(['C', 'D', 'E-', 'B']).name, 'C harmonic minor')
 
+    def testHarmonicMinorKeepsItsSeventhAfterNextPitch(self):
+        sc = scale.HarmonicMinorScale('g4')
+        sc.nextPitch('a4')
+        self.assertEqual(self.pitchOut(sc.pitches), '[G4, A4, B-4, C5, D5, E-5, F#5, G5]')
+
     def testDeriveByDegree(self):
         sc1 = scale.MajorScale()
         self.assertEqual(str(sc1.deriveByDegree(7, 'G#')),