Pre-Proposal: Add Validation somewhere easily accessible

Andreas Abel abela at
Thu Sep 25 07:52:15 UTC 2014

To use the Errors type in a nice way:

* I'd like to import it from a module named Control.Applicative.Error(s)

* be able to work it without reference to Lift, Constant, Pure, Other.

The second point would amout to, I guess,
* newtype Errors instead of type Errors
* having 'runErrors' that give me the result or the errors.

Just some initial thoughts,

On 24.09.2014 21:06, Ross Paterson wrote:
> On Mon, Sep 22, 2014 at 05:43:05PM +0200, Andreas Abel wrote:
>> UPDATE: I found that "Errors e" on
>> seems to be doing the job of "Validation" already (no nice names of the
>> operations, though).
> Which operations and names would you like?

Andreas Abel  <><      Du bist der geliebte Mensch.

Department of Computer Science and Engineering
Chalmers and Gothenburg University, Sweden

andreas.abel at

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