Re: [Haskell-cafe] [Alternative] summary of my understanding so far

On 17/12/2011, at 3:35 PM, Matthew Farkas-Dyck wrote:

On 15/12/2011, Gregory Crosswhite wrote:

...

1) Documentation really needs to be improved 2) some/many cannot be physically separated from Alternative, but there *might* be an advantage to creating a subclass for them anyway purely for the sake of conveying more information about a type to users 3) Maybe and [] are sensible instances of Alternative, even if many/some often enters an infinite loop. 4) It is possible to provide special instance of many/some that satisfy the equations of many/some, with the slight disadvantage that these solutions are no longer the "least" solutions.

Based on all of this, at this moment in time it seems to me that the most sensible way forward is to fix the documentation, tweak the definition of Alternative to no longer require the least solutions of the equations, and then to adopt the new instances for Maybe and [].

Thoughts?

(1) If we do (4), then the documentation ought to be adequate as-is.

No. Not by a country mile. It's better than "non-existent". It's better than "misleading". But it's not even on the same *continent* as "adequate". A lot of Haskell packages have pretty much the same level of documentation. And I didn't pay one single cent for it, so I can't scream too loudly. But let's not kid ourselves.