Merging symbols in common lisp

Question

I want to insert a char into a list. However, I want to merge this char with the last symbol in the list. With appends and cons the result is always two different symbols.

Answer 1

Define this:

(defun symbol-append (&rest symbols) 
  (intern (apply #'concatenate 'string 
                 (mapcar #'symbol-name symbols))))

and then use it as:

* (symbol-append 'a 'b 'c)
ABC

* (apply #'symbol-append '(a b c))
ABC

If you expect your arguments to contain stuff besides symbols, then replace symbol-name with:

   (lambda (x)
     (typecase x ...)) 

or a pre-existing CL function (that I've forgotten :() that stringifies anything.