Merge ByteString and Text functions and types

[ddssff]

In order to eliminate duplicate code, all the ByteString and Text specific functions are merged into functions that have a type parameter b with the constraints forall b. (Pack b) =>. The forall, along with {-# LANGUAGE ScopedTypeVariables #-}, lets you use b in signatures throughout the function to refer to the exact type used in the main signature. Remove the B and T suffixes from all functions and types. You may also need {-# LANGUAGE TypeFamilies #-}.

[ddssff]

Also, I don't see much value in definitions like this:

emptySTRLESeq :: ST s (STRef s (Seq (Maybe b)))
emptySTRLESeq = newSTRef DS.empty

I would just replace uses of emptySTRLESeq with newSTRef DS.empty everywhere, and similarly for other functions. Furthermore, I don't think you need to encode the type in symbol names like brleseqstackempty - just call it stackRef, and rename brleseqstackemptyr just stack.

[Matthew-Mosior]

@ddssff do you think we should move away from implementing via the ST monad right (replace with Writer monad)? If so a lot of these functions probably wont be necessary anymore. I still wonder about performance though, doesn't the ST monad allow for scoped mutation (should allow for a Haskellish way to maintain near C performance)? Maybe the current ST monad implementation isn't any faster than say implementing via the Writer monad (I like the Writer monad way much better).

[ddssff]

Honestly, I don't understand how the ST monad affects performance. I did the writer monad implementation by incrementally transforming the ST monad implementation, so first I had to do the work described in this ticket - parameterize the ByteString / Text type, inline trival functions and types, etc. Once that is done we can convert to Writer monad but keep the ST monad version. Then perhaps some benchmarking.

[ddssff]

My guess is that high performance is something you will have to do afterwards. But regular pure haskell does a pretty good job on its own.

[ddssff]

One more suggestion - use pattern matching and the maybe function instead of fromJust and isNothing.

[Matthew-Mosior]

Sorry for the delay, will be looking into this soon.

[ddssff]

No problem, I've been very busy.