Inline the findSchedulePrefix predicate.

The function is only used in one place, with a constant
predicate. There was no point in it being a parameter.

dejafu/Test/DejaFu/SCT.hs

@@ -332,7 +332,7 @@ sctBound :: MonadRef r n
 sctBound memtype cb conc = go initialState where
   -- Repeatedly run the computation gathering all the results and
   -- traces into a list until there are no schedules remaining to try.
-  go dp = case nextPrefix dp of
+  go dp = case findSchedulePrefix dp of
     Just (prefix, conservative, sleep) -> do
       (res, s, trace) <- runConcurrent scheduler
                                        memtype
@@ -348,9 +348,6 @@ sctBound memtype cb conc = go initialState where
 
     Nothing -> pure []
 
-  -- Find the next schedule prefix.
-  nextPrefix = findSchedulePrefix (>=initialThread)
-
   -- The DPOR scheduler.
   scheduler = dporSched memtype (cBound cb)
 

dejafu/Test/DejaFu/SCT/Internal.hs

@@ -116,18 +116,12 @@ initialState = DPOR
 -- to-do set. The intent is to put the system into a new state when
 -- executed with this initial sequence of scheduling decisions.
 findSchedulePrefix
-  :: (ThreadId -> Bool)
+  :: DPOR
-  -- ^ Some partitioning function, applied to the to-do decisions. If
-  -- there is an identifier which passes the test, it will be used,
-  -- rather than any which fail it. This allows a very basic way of
-  -- domain-specific prioritisation between otherwise equal choices,
-  -- which may be useful in some cases.
-  -> DPOR
   -> Maybe ([ThreadId], Bool, Map ThreadId ThreadAction)
-findSchedulePrefix predicate = listToMaybe . go where
+findSchedulePrefix = listToMaybe . go where
   go dpor =
     let prefixes = here dpor : map go' (M.toList $ dporDone dpor)
-    in case concatPartition (\(t:_,_,_) -> predicate t) prefixes of
+    in case concatPartition (\(t:_,_,_) -> t >= initialThread) prefixes of
          ([], choices) -> choices
          (choices, _)  -> choices