Haskell Platform decision: time to bless parsec 3?

Stephen Tetley stephen.tetley at gmail.com
Sat Nov 6 13:47:47 EDT 2010


On 6 November 2010 16:24, Martijn van Steenbergen
<martijn at van.steenbergen.nl> wrote:

> * Most of the combinators in Text.Parsec.Combinator have types specialized
> to ParsecT (with a Stream class constraint as consequence) while they could
> be defined in terms of Applicative only. I think these should be rewritten
> in terms of Applicative (or Monad if absolutely necessary) whenever
> possible.

Couldn't an independent package could achieve this goal?

If the combinators were defined in Parsec they would be under the
Parsec namespace rather than Control.* and Parsec having type
specialized versions might produce better error messages.

Ross Paterson already has an alternative implementation of the Perm
combinators on Hackage that are defined in solely with Applicative
(action-permutations).


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