Added caching of some things in Value, to be updated only after Chang…

…ed() is called.

Decreases time required to level-up from 5 seconds to 3 seconds.
  Does this make it worth it to no longer prune the redundant calls?
  Nope, removing pruning increases the level-up time up to 12 seconds
  Looks like the 1.7 seconds to remove the redundant calls is worth it.
Current time looks decent, so I'll only look into more optimizations if needed.

Character.py

@@ -32,7 +32,6 @@ def _escape(unescaped):
         escaped = escaped.replace(v,k)
     return escaped
 
-
 def _split_by_special(line):
     """
     Splits the input string according to the special characters used by the save file format.
@@ -289,6 +288,29 @@ def Open(filename):
             c.AddVal(Value.FromLineSplit(linesplit))
         return c
 
+def _cached(fn):
+    """
+    Use between @property and the function declaration,
+      or right before a normal function.
+    Assumes the existence of self._timesChanged,
+      which is incremented whenever the cached values should be recalculated.
+    """
+    cache = []
+    lastCalled = [-1]
+    def output(self,*args,**kwargs):
+        if lastCalled[0]!=self._timesChanged:
+            del cache[:] #Clears the cache, keeping references
+            lastCalled[0] = self._timesChanged
+        for inp,out in cache: #Uses equals instead of a dict because arguments might not be hashable.
+            if inp==(args,kwargs):
+                return out
+        else:
+            ans = fn(self,*args,**kwargs)
+            cache.append( ((args,kwargs),ans) )
+            return ans
+    return output
+
+
 class Value(object):
     """
     Base class for Stats and Skills
@@ -300,6 +322,7 @@ class Value(object):
                      ('"','\\"'),]
     def __init__(self,Value=None,Names=None,Parents=None,Children=None,Options=None,Description=""):
         self.Events = lambda *args:None
+        self._timesChanged = 0 #needed for _cached
         self.char = None
         self.Names = [] if Names is None else Names
         self.requestedParents = [] if Parents is None else Parents
@@ -358,6 +381,7 @@ def Description(self,val):
     def NoBonus(self):
         return 'NoBonus' in self.Options
     def Changed(self,propagate=True):
+        self._timesChanged += 1
         self.Events('Value Changed',self)
         self.Events(self.Type+' Changed',self)
         if propagate:
@@ -369,13 +393,17 @@ def ApplyLevelUp(self):
             self.Delta = 0
     def SelfBonus(self,asker=None,levelled=False):
         return 0
+    @_cached
     def Bonus(self,asker=None,levelled=False):
         return self.SelfBonus(asker,levelled) + sum(par.Bonus(self,levelled) for par in self.Parents)
+    @_cached
     def CategoryBonus(self,asker=None,levelled=False):
         return sum(par.Bonus(self,levelled) for par in self.Parents if isinstance(par,Skill) and not par.NoBonus)
+    @_cached
     def StatBonus(self,asker=None,levelled=False):
         return (sum(par.Bonus(self,levelled) for par in self.Parents if isinstance(par,Stat))
                + sum(par.StatBonus(self,levelled) for par in self.Parents if par.NoBonus))
+    @_cached
     def ItemBonus(self,asker=None,levelled=False):
         return (sum(par.Bonus(self,levelled) for par in self.Parents if isinstance(par,Item))
                 +sum(par.Bonus(self,levelled) for par in self.Parents if par.NoBonus))
@@ -536,6 +564,7 @@ def CommonlyUsed(self,val):
             self.Options.remove('CommonlyUsed')
         self.Changed(False)
     @property
+    @_cached
     def Costs(self):
         """
         Return a list of integers given the cost of levelling up skills.
@@ -558,6 +587,7 @@ def Costs(self,val):
         self.Changed()
     def CostSaveString(self):
         return '' if self._costs is None else ','.join(str(i) for i in self._costs)
+    @_cached
     def DPspent(self):
         return sum(self.Costs[:self.Delta])