Corrected BACK action : 1) cannot create cycle 2) correct backward movement

Config.py

@@ -82,7 +82,7 @@ class Config :
     right = 5
     print("stack :",[self.getAsFeature(ind, "ID") for ind in self.stack], file=output)
     print("history :",[trans.name for trans in self.history[-10:]], file=output)
-    print("historyPop :",[(c[0].name,c[1]) for c in self.historyPop[-10:]], file=output)
+    print("historyPop :",[(c[0].name,c[1],c[2]) for c in self.historyPop[-10:]], file=output)
     toPrint = []
     for lineIndex in range(self.wordIndex-left, self.wordIndex+right) :
       if lineIndex not in range(len(self.lines)) :

Decode.py

@@ -64,7 +64,7 @@ def decodeModel(ts, strat, config, network, dicts, debug) :
       candidate = candidates[0][1]
       if debug :
         config.printForDebug(sys.stderr)
-        print(" ".join(["%s%.2f:%s"%("*" if score[1] else " ", score[0], score[2]) for score in scores])+"\n"+("-"*80)+"\n", file=sys.stderr)
+        print(" ".join(["%s%.2f:%s"%("*" if score[1] else " ", score[0], score[2]) for score in scores])+"\n"+"Chosen action : %s"%candidate+"\n"+("-"*80)+"\n", file=sys.stderr)
       moved = applyTransition(ts, strat, config, candidate)
 
   EOS.apply(config, strat)

Transition.py

@@ -18,8 +18,7 @@ class Transition :
   def apply(self, config, strategy) :
     data = None
     
-    if "BACK" not in self.name :
-      config.historyHistory.add(str([t[0].name for t in config.historyPop]))
+    config.historyHistory.add(str([t[0].name for t in config.historyPop]))
 
     if self.name == "RIGHT" :
       applyRight(config)
@@ -39,7 +38,7 @@ class Transition :
       exit(1)
     config.history.append(self)
     if "BACK" not in self.name :
-      config.historyPop.append((self,data))
+      config.historyPop.append((self,data,None))
 
   def appliable(self, config) :
     if self.name == "RIGHT" :
@@ -146,8 +145,8 @@ def scoreOracleReduce(config, ml) :
 ################################################################################
 def applyBack(config, strategy, size) :
   for i in range(size) :
-    trans, data = config.historyPop.pop()
-    config.moveWordIndex(-strategy[trans.name])
+    trans, data, movement = config.historyPop.pop()
+    config.moveWordIndex(-movement)
     if trans.name == "RIGHT" :
       applyBackRight(config)
     elif trans.name == "LEFT" :
@@ -236,6 +235,10 @@ def applyTransition(ts, strat, config, name) :
   transition = [trans for trans in ts if trans.name == name][0]
   movement = strat[transition.name] if transition.name in strat else 0
   transition.apply(config, strat)
-  return config.moveWordIndex(movement)
+  moved = config.moveWordIndex(movement)
+  movement = movement if moved else 0
+  if len(config.historyPop) > 0 and "BACK" not in name :
+    config.historyPop[-1] = (config.historyPop[-1][0], config.historyPop[-1][1], movement)
+  return moved
 ################################################################################
 

main.py

@@ -41,7 +41,7 @@ if __name__ == "__main__" :
   os.makedirs(args.model, exist_ok=True)
 
   Util.setDevice(torch.device("cuda" if torch.cuda.is_available() else "cpu"))
-  print("Using device : %s"%Util.getDevice())
+  print("Using device : %s"%Util.getDevice(), file=sys.stderr)
   random.seed(args.seed)
   torch.manual_seed(args.seed)