assignment recognizer

src/App/Fontifier.hs

@@ -180,18 +180,28 @@ invalidReads s = [] -- do magic here
 invalidWrites s = [] -- do magic here
 
 -- (alternative if easier than invalid read/invalid write separated)
-invAcc :: [(String,Slice,Bool)] -> CheckString -> Slices
-invAcc a ('{':t) = invAcc (enterBlock a) t
-invAcc a ('}':t) = invAcc (leaveBlock a) t
-invAcc a ('[':t) = invAcc a (drop g t)        -- TODO check reads in first part
+invAcc :: [(String,Slice,Bool)] -> String -> CheckString -> Slices
+invAcc a _ ('{':t) = invAcc (enterBlock a) "" t
+invAcc a accumStr ('}':t) = invAcc (leaveBlock a) "" t
+invAcc a accumStr ('[':t) = invAcc a accumStr (drop g t)       -- TODO check reads in first part
   where g = fromJust (elemIndex ':' t)
--- when reading a assignment :word: =
+-- when reading an assignment :word: =
 -- put :word:, slice, false in the list
 -- when reading a read access scan the list for the variable
 -- if it is found set its boolean value to true
 -- if it is not found add its slice to the result
 -- all variables with false at the end of a block are unused
-invAcc _ _ = []
+invAcc a accumStr (c:t) = let chkAccum = checkAccum 0 accumStr  -- we need to track the actual index position in the string
+                          in if isNothing chkAccum
+                             then invAcc a (accumStr ++ [c]) t -- no assignment in accumStr
+                             else invAcc (a ++ [fromJust chkAccum]) "" t -- assignment in accumStr
+invAcc _ _ _ = []
+
+checkAccum :: Int -> String -> Maybe (String, Slice, Bool)
+checkAccum offset accumStr = ((Tdfa.matchOnceText §~ "(\\**[[:word:]]+)[[:blank:]]*=") accumStr) >>= matchToA
+          where matchToA (before, match, after) =
+                  let m = match ! 1 -- extract the match group (0 = the whole match)
+                  in Just (fst m, (offset+(fst (snd m)), offset+(fst (snd m))+(snd (snd m))), False)
 
 enterBlock :: [(String,Slice,Bool)] -> [(String,Slice,Bool)]
 enterBlock = map (\(v,s,b) -> ('*':v,s,b))