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Validator.Or combinator
websharperf#

Been trying to get an Or combinator that will allow either kind of values and I can't seem to get it working. I end up with a failure case on what seems to be the second validation as opposed to the first.

Wouldn't mind hearing it can be done simpler or more reliable too:

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type Result<'a> = IntelliFactory.Formlet.Base.Result<'a>

module Formlet =
    let Either successF failureF =
        Formlet.MapResult (function
            | Result.Success v -> successF v
            | Result.Failure e -> failureF e
        )
    let DoubleMap successF failureF =
        Either (successF >> Result.Success) (failureF >> Result.Failure)

type IntelliFactory.Formlet.Base.Validator with
    member x.IsGuid text flet = Validator.IsRegexMatch "[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}" text flet
    member x.IntList text flet = Validator.IsRegexMatch "^\d+(, ?\d+)*$" text flet
    member x.Or v1 v2 flet =
        flet
        |> v1
        |> Formlet.Either
            (Formlet.Return >> Result.Success)
            (fun msg1s ->
                flet
                |> v2
                |> Formlet.DoubleMap id (fun msg2s -> msg2s @ msg1s |> Seq.distinct |> Seq.toList)
                |> Result.Success)
        |> Formlet.Switch
.

I understand what's happening above.

Because the first formlet fails to produce a value only the second formlet is ever displayed as such the only form of validation that I see happening is the second one.

Starting to think it would be much easier to do this with Formlet.Is, only problem is I wouldn't be reusing the existing Regex validator.

By on 6/19/2013 6:30 AM ()

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