foo.fs

let checkMethodImplIsPartialMatchForInterfaceMethod (minfo: MethInfo) (mimpl: ILMethodImpl) =
    minfo.IsFinal &&
    minfo.IsInterfaceMethod &&
    mimpl.OverrideBy.ArgCount = List.sum minfo.NumArgs && 
    mimpl.OverrideBy.GenericArity = minfo.GenericArity

let GetIntrinsicInterfaceOverrideMethodSetsUncached ((optFilter, ad, allowMultiIntfInst), m, ty) =

    assert optFIlter.IsSome
    assert isInterfaceTy g ty

    // Collect all the relevant method impls related to methods of this name
    (ty,[]) ||> FoldPrimaryHierarchyOfType (fun ty (acc: MethInfo list) ->
        // Currently, F# supports DIMs from IL types, not F# defined types.
        match tryAppTy g ty with
        | ValueSome (tcref, _) when tcref.IsILTycon ->
            // MethodImpls contains a list of methods that override.
            // OverrideBy is the method that does the overriding.
            // Overrides is the method being overriden.
            // Find the Overrides method first with optFilter, then search for the OverrideBy method.
            //     If the OverrideBy method is found, add it to the method set for that type in the hierarchy.
            tcref.ILTyconRawMetadata.MethodImpls.AsList
            |> List.concat (fun mimpl ->
                if optFilter.Value = mimpl.Overrides.MethodRef.Name then
                    let ovbyName = mimpl.OverrideBy.Name

                    GetImmediateIntrinsicMethInfosOfType (Some ovbyName, ad) g amap m ty
                    |> List.filter (checkMethodImplIsPartialMatchForInterfaceMethod mimpl)
                else
                    []) @ acc
        | _ -> acc
    ) g amap m allowMultiIntfInst