Regenerate tempo timings after adding markers

timings.py

@@ -11,6 +11,12 @@ class TimingError(Exception):
     def __str__(self):
         return f'{self.message} in string "{self.at}"'
 
+def namespaced_key(x):
+    if x is None:
+        return (1, x)
+    else:
+        return (0, x)
+
 class Timings:
     def __init__(self):
         self._timings = []
@@ -92,18 +98,17 @@ class Timings:
         self._tempo_objects.append((tempo, beats, at))
         self._resolved = False
 
+    def resolve_tempo(self):
+        self._tempo_objects.sort(key=lambda x: namespaced_key(x[2].evaluate()))
+        self._tempo = [(t, b, a.evaluate()) for (t, b, a) in self._tempo_objects]
+
     def resolve(self, final=False):
         try:
-            def namespaced_key(x):
-                if x is None:
-                    return (1, x)
-                else:
-                    return (0, x)
-            self._tempo_objects.sort(key=lambda x: namespaced_key(x[2].evaluate()))
-            self._tempo = [(t, b, a.evaluate()) for (t, b, a) in self._tempo_objects]
+            self.resolve_tempo()
             for name in self._marker_objects.keys():
                 if self._marker_objects[name] is not None:
                     self._markers[name] = self._marker_objects[name].evaluate()
+                    self.resolve_tempo()
             self._timings.sort(key=lambda x: namespaced_key(x.evaluate()))
         except Exception:
             if final: