Method for determining valid name syntax?

Question

This question 40194 asks about work arounds to check and replace variable names which are invalid in a specific MMA function context. For that case testing using the function itself is the most reliable approach, but I'd like a more general method.

Is there a builtin function or a more general way to test syntax and validity?

One idea, if there are error messages, we can use Check:

varCheckQ[s_String]:=Check[SyntaxQ[Symbol[s]], False] // Quiet
varCheckQ/@{"1st","two wrds","no_good","al.most","ok"}
(* {False, False, False, False, True} *)

Or, maybe try to match with unevaluated

varNameQ[s_String]:=!BooleanQ[Quiet@Symbol[s]==Unevaluated@Symbol[s]]
varNameQ/@{"1st","two wrds","no_good","al.most","ok"}
(* {False, False, False, False, True} *)

These work, but don't seem very robust. Is there a utility function defined somewhere that already does this using MMA's rules?

Answer 1

There is the undocumented function Internal`SymbolNameQ:

Internal`SymbolNameQ /@ {"1st", "two wrds", "no_good", "al.most", "ok"}

 {False, False, False, False, True}