Is there a way to define a function which evaluates itself regardless of HoldAll, HoldFirst, ... ?


I'm writing a function which makes it easier to document other functions using ::usage, SyntaxInformation and code completion. I also use code generation and I want to document the generated code.

Therefore I need to define new symbols with a usage message and remove them like this:

(* I already get an error message here since `Evaluate` wants to evaluate
  `Symbol[name]` but `name` is not a string yet *)
NewSymbol[name_String] := Evaluate[Symbol[name]];

Remove[NewSymbol["test"]] (* DOES NOT WORK *)
NewSymbol["test"]::usage = "This is a test"; (* DOES NOT WORK *)

(* In order to make it work I have to use an additional `Evaluate`*)

(* The same is true if I want to use `Remove` *)

Evaluate[NewSymbol["test"]]::usage = "This is a test";
  • 2
    $\begingroup$ What is the purpose of this? What goal is it intended to serve? With that info, answers might be more helpful. $\endgroup$ Apr 8 '20 at 13:08
  • $\begingroup$ @MariusLadegårdMeyer Thank you for your comment. Is the intention clear now? $\endgroup$
    – Qbyte
    Apr 8 '20 at 13:16

Stay away from Evaluate altogether and use With to inject into functions that hold their arguments:

createSymbolAndSetUsage[sym_String, usage_String] := With[
    {symbol = Symbol @ sym},
    symbol::usage = usage;

createSymbolAndSetUsage["Foo", "Foo does what it does"]
(* Foo *)

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