scanner

Fast non-backtracking incremental combinator parsing for bytestrings

On hackage: https://hackage.haskell.org/package/scanner

On stackage: https://www.stackage.org/package/scanner

It is often convinient to use backtracking to parse some sophisticated input. Unfortunately it kills performance, so usually you should avoid backtracking.

Often (actually always, but it could be too hard sometimes) you can implement your parser without any backtracking. It that case all the bookkeeping usuall parser combinators do becomes unnecessary. The scanner library is designed for such cases. It is often 2 times faster then attoparsec.

As an example, please checkout redis protocol parser included into the repo, both using attoparsec and scanner libraries: https://github.com/Yuras/scanner/tree/master/examples/Redis

Benchmark results:

But if you really really really need backtracking, then you can just inject attoparsec parser into a scanner: https://hackage.haskell.org/package/scanner-attoparsec