unable to display fshow for tagVec

bs/TagEngine.bs

@@ -1,4 +1,4 @@
-package TagEngine() where
+package TagEngine(TagEngine(..), mkTagEngine) where
 
 import Vector
 import Util
@@ -10,6 +10,10 @@ data Tag numTags
     | Tail
     deriving (Bits, Eq, FShow)
 
+interface (TagEngine :: # -> *) numTags =
+    requestTag :: ActionValue UIntLog2N(numTags)
+    retireTag  :: UIntLog2N(numTags) -> Action
+
 initTagNext :: Integer -> Module(Reg (Tag numTags))
 initTagNext i = do
     t :: Reg (Tag numTags)
@@ -22,11 +26,6 @@ initTagTail = do
     t <- mkReg Tail
     return t
 
-interface (TagEngine :: # -> *) numTags =
-    requestTag :: ActionValue UIntLog2N(numTags)
-    retireTag  :: UIntLog2N(numTags) -> Action
-
-
 initTagVec :: Module(Vector numTags (Reg (Tag numTags)))
 initTagVec = 
     do
@@ -44,6 +43,20 @@ mkTagEngine =
         tagVec :: Vector numTags (Reg (Tag numTags))
         tagVec <- initTagVec
 
+        fileHandle   :: Handle <- openFile "compile.log" WriteMode
+
+        cycle <- mkReg 0
+        end_cycle <- mkReg 4
+
+        addRules (simulate_for cycle end_cycle)
+
+        addRules $
+            rules
+                "display": when True ==>
+                    do
+                        $display (fshow (tagVec !! 0))
+                        $finish
+
         counter <- mkReg(0 :: UIntLog2N(numTags))
         return $
           interface TagEngine
@@ -56,9 +69,3 @@ mkTagEngine =
             retireTag tag = do
                 -- placeholder
                 counter := 0
-    where
-        a = "Hello"
-        idx_last :: Integer = (fromInteger |> valueOf numTags) - 1
-
-a :: Integer
-a = 3

bs/Top.bs

@@ -101,6 +101,7 @@ mkSim :: Module Empty
 mkSim = do
   let cfg          :: BRAM_Configure = defaultValue
 
+  tagEngine :: TagEngine 5 <- mkTagEngine
   count            :: Reg (UInt 3) <- mkReg 0;
   initCFunctions :: Reg Bool <- mkReg False;
   core             :: Core FCLK <- mkCore;

bs/Util.bs

@@ -1,4 +1,15 @@
-package Util((|>)) where
+package Util((|>), simulate_for) where
 
 (|>) :: (a -> b) -> a -> b
-f |> x = f x;
+f |> x = f x;
+
+simulate_for :: (Bits a n, Arith a, Eq a) => Reg a -> Reg a -> Rules
+simulate_for curr_cycle end_cycle =
+  rules
+    "count_cycle_rule": when True ==> action
+      curr_cycle := curr_cycle + 1
+      if curr_cycle == end_cycle
+        then 
+          $finish
+        else
+          $display "cycle = " curr_cycle