Replace toScaleDegree with parseSpelledPitchOrScaleDegree to support chord charts written in key signature or numbers.

src/pco_chordspkg/notation.nim

@@ -314,6 +314,16 @@ func toScaleDegree*(k: Key, sp: SpelledPitch): ScaleDegree =
   ]#
 
 
+func parseSpelledPitchOrScaleDegree*(key: Key, str: string): ScaleDegree =
+  try:
+    let pitch =parseSpelledPitch(str)
+    return toScaleDegree(key, pitch)
+  except:
+    try: return parseScaleDegree(str)
+    except:
+      raise newException(ValueError,
+        str & " is not a recognized pitch or scale degree")
+
 
 func transpose*(k: Key, steps: int): Key =
   Key(