///

/// * not to loose `FSharpSymbolUse` for `nameof` argument, because we erase it with `Expr.Const(Const.String ...)` further in this function.

let (|LastPartOfLongIdentStripParens|_|) expr =

let rec findIdents expr(isTypeApp : bool)=

let rec findIdents expr =

match expr with

| SynExpr.Ident ident ->

if not isTypeApp then

TcExprOfUnknownType cenv env tpenv expr |> ignore

Some ident

| SynExpr.TypeApp (expr, _, typeArgs, _, _, mTypeArgs, m) ->

TcExprOfUnknownTypeThen cenv env tpenv expr [ DelayedTypeApp (typeArgs, mTypeArgs, m) ] |> ignore

//TcTypesOrMeasures None cenv ImplictlyBoundTyparsAllowed.NewTyparsOK CheckConstraints.NoCheckCxs ItemOccurence.Use env tpenv typeNames m |> ignore

findIdents expr true

| SynExpr.LongIdent(_, LongIdentWithDots(idents, _), _, _) when not (List.isEmpty idents) ->

if not isTypeApp then

TcExprOfUnknownType cenv env tpenv expr |> ignore

List.tryLast idents

| SynExpr.Ident ident -> Some ident

| SynExpr.TypeApp (expr = expr) -> findIdents expr

| SynExpr.LongIdent(_, LongIdentWithDots(idents, _), _, _) -> List.tryLast idents

| _ -> None

findIdents expr false

findIdents expr

let tcExpr = function

| SynExpr.Ident _

| SynExpr.LongIdent(_, LongIdentWithDots _, _, _) as expr ->

ignore (TcExprOfUnknownType cenv env tpenv expr)

| SynExpr.TypeApp (expr, _, types, _, _, _, m) as fullExpr ->

let idents =

match expr with

| SynExpr.LongIdent(_, LongIdentWithDots(idents, _), _, _) -> idents

| SynExpr.Ident ident -> [ident]

| _ -> []

match idents with

| [] -> ()

| idents ->

// try to type check it as type application, like A.B.C<D<G>>

match ResolveTypeLongIdent cenv.tcSink cenv.nameResolver ItemOccurence.UseInType OpenQualified env.eNameResEnv env.eAccessRights idents (TypeNameResolutionStaticArgsInfo.FromTyArgs types.Length) PermitDirectReferenceToGeneratedType.No with

| ResultOrException.Result tcref ->

ignore (TcTypeApp cenv NewTyparsOK NoCheckCxs ItemOccurence.UseInType env tpenv m tcref [] types)

| _ ->

// now try to check it as generic function, like func<D<G>>

ignore (TcExprOfUnknownType cenv env tpenv fullExpr)

| _ -> ()

let rec stripParens expr =

match expr with

let cleanSynArg = stripParens synArg

match cleanSynArg with

| LastPartOfLongIdentStripParens lastIdent ->

tcExpr cleanSynArg

let r = expr.Range

// generate fake `range` for the constant the `nameof(..)` we are substituting

let constRange = mkRange r.FileName r.Start (mkPos r.StartLine (r.StartColumn + lastIdent.idText.Length + 2)) // `2` are for quotes