Re: [Haskell-cafe] How to speedup generically parsing sum types?

On 3 November 2011 17:38, Twan van Laarhoven wrote:

Perhaps relying on Attoparsec backtracking for picking out the right alternative from the sum is the problem. You could try it with Maybe:

Good idea. I implemented and committed it and the BigSum/fromJSON/generic benchmark goes from 13.6 us to 11.3 us. Still a lot slower than the 4.1 us of SYB or the 414.9 ns of TH but an improvement nonetheless. Thanks for the idea! Bas