Programmatically find-and-replace custom sequence

Question

I need to write a command which will apply to my buffer custom, predefined copy-and-replace sequence.

What I have is:

(defun custom-processor ()
  "Formats logs to human-readable format"
  ((replace-in-the-buffer "\n" "\n\n\n")
   (replace-in-the-buffer "\t" "\n")))

(defun replace-in-the-buffer (from to)
  "Replaces in the current buffer all occurences of from to to (not interactively)"
  (while (re-search-forward from nil t)
    (replace-match to nil nil)))

It is basically working for simple characters like letters or numbers, but the case is I need to use it with new lines (\n) and tabs (\t) - the error I get is:

Debugger entered--Lisp error: (invalid-function (replace-in-the-buffer "\n" "\n\n\n"))
  ((replace-in-the-buffer "\n" "\n\n\n") (replace-in-the-buffer "\011" "\n"))
  custom-processor()
  eval((custom-processor) nil)
  elisp--eval-last-sexp(nil)
  eval-last-sexp(nil)
  funcall-interactively(eval-last-sexp nil)
  call-interactively(eval-last-sexp nil nil)
  command-execute(eval-last-sexp)

I use EMACS for 10y+ but now just starting to leverage it with Lisp programming. Please help.

Answer 1

Double parenthesis are the culprit.

I guess you forgot to type progn

(defun custom-processor ()
  "Formats logs to human-readable format"
  (progn 
    (replace-in-the-buffer "\n" "\n\n\n")
    (replace-in-the-buffer "\t" "\n")))

or just remove them:

(defun custom-processor ()
  "Formats logs to human-readable format"
  (replace-in-the-buffer "\n" "\n\n\n")
  (replace-in-the-buffer "\t" "\n"))