Unexpected FS0812 when property has same name as DU case

[cmeeren]

Consider this code:

type MyId =
    | IdA of int
    | IdB of string

    member this.IdA =
        match this with
        | IdA x -> Some x
        | _ -> None


let onlyIdA (ids: MyId list) = ids |> List.choose _.IdA

The last line fails to compile with an error on _.IdA:

Error FS0812 : The syntax 'expr.id' may only be used with record labels, properties and fields

I would expect this to compile, since IdA is indeed a property.

[cmeeren]

This is not related to shorthand lambda, it also fails for normal lambdas:

let onlyIdA (ids: MyId list) = ids |> List.choose (fun x -> x.IdA)
                                                            ^^^^^

[0101]

We should probably add a warning when defining a member with the same name as a DU case.

We might also want to fix the current error message.

[vzarytovskii]

It for sure has been like that for some time, definitely not a bug.