F# active pattern as non-static member

Question

I'm not sure if non-static public member active patterns are allowed but you can define them without the compiler complaining. If they are allowed what's the syntax for matching against one? The compiler is giving me a type mismatch for Foo in FooBar2.doSomething. Expecting a 'a -> Choice<'b,'c> given 'a -> 'd -> Choice<unit,unit>

// No error in this class, static works great
type FooBar() = 
    static member (|Foo|Bar|) (x, y) =
        match x = y with
        | true -> Foo
        | false -> Bar

    member x.doSomething y =
        match x, y with
        | Foo -> ()
        | Bar -> ()

type FooBar2() = 
    member x.(|Foo|Bar|) y =
        match x = y with
        | true -> Foo
        | false -> Bar

    // compiler error on "Foo"    
    member x.doSomething y =
        match y with
        | Foo -> ()
        | Bar -> ()

Answer 1

Active patterns should not be used as members. The fact that these compile at all is a compiler bug that we'll fix (thanks for the report :) ). Use local or module-bound "let"s to define an active pattern.