Question

Imagine I got some kind of function called by a macro to return an expression like

(do-something 'argument)

therefore the function has to look like

(defun form-expression (arg)
  `(do-something ',arg))

But when called (form-expression "foobar"), as the wrapping macro has to receive strings as parameters, the result is:

(do-something '"foobar")

How can I “remove” the quotation marks of the given string?

Answer 1

If I’m understanding you correctly, for an input of “foobar”, you want the result of form-expression to be (do-something 'foobar).

If that’s the case, use the intern function. You’ll either need to pass the interned string (as in (form-expression (intern "foobar"))), or you’ll need to do type dispatch in the function

(defun form-expression (arg)
   `(do-something ',(if (stringp arg) (intern arg) arg)))

Actually, since you’re dispatching on the type of the argument, this is a perfect place to use a method.

(defmethod form-expression (arg) `(do-something ',arg))
(defmethod form-expression ((str string)) `(do-something ',(intern str)))