refactor a bit

bs/TagEngine.bs

@@ -1,4 +1,6 @@
-package TagEngine(TagEngine(..), mkTagEngine) where
+package TagEngine(
+    TagEngine(..),
+    mkTagEngine) where
 
 import Vector
 import Util
@@ -31,14 +33,14 @@ initTagTail = do
 
 initTagVec :: Module(Vector numTags (Reg (Tag numTags)))
 initTagVec = 
-    do
-        tagVecSequential :: Vector numTags (Reg (Tag numTags))
-        tagVecSequential <- mapM (\idx -> initTagNext (idx+1)) genVector
-        let idxLast :: Integer = (fromInteger |> valueOf numTags) - 1
-        tailTag <- initTagTail
-        -- the tail of our TagVec should be `Tail` not `Next`
-        let finalTagVec = update tagVecSequential idxLast tailTag
-        return finalTagVec
+    let
+        lastIdx :: Integer = (fromInteger |> valueOf numTags) - 1
+        initByIdx currIdx = 
+            if (currIdx < lastIdx)
+                then initTagNext (currIdx + 1)
+                else initTagTail
+    in
+        mapM initByIdx genVector
 
 mkTagEngine :: Module (TagEngine numTags)
 mkTagEngine =
@@ -46,8 +48,6 @@ mkTagEngine =
         tagVec :: Vector numTags (Reg (Tag numTags))
         tagVec <- initTagVec
 
-        fileHandle   :: Handle <- openFile "compile.log" WriteMode
-
         debugOnce <- mkReg True
 
         addRules $