[Haskell-cafe] Pearl! I just proved theorem about impossibility of monad transformer for parsing with (1) unbiased choice and (2) ambiguity checking before running embedded monadic action (also, I THREAT I will create another parsing lib)

[Roman]

Askar,

> 2. We need to prepend "fromEither" before each parser, in which we plan to fail with error messages.

Are you familiar with selective functors [1]? That library might be
helpful in your case.

[1] https://hackage.haskell.org/package/selective-0.4.2