Is there a apply-function-to-region-lines in emacs?

Question

A lot of my work involves searching and deleting unnecessary lines of code. So I create a macro, and then select all lines (C-x h) and then run the command (apply-macro-to-region-lines). I managed to save that command and placed it in my .emacs file; I called it cut_it_now. But now my function is not a macro anymore, so I can't use the (apply-macro-to-region-lines) function anymore. Do you know if there is (apply-function-to-region-lines) implemented somewhere?

Many thanks,

D

Answer 1

Note that you can still use apply-macro-to-region-lines with a macro generated from code, provided the macro is defined as a vector or string. With a custom apply-named-macro-to-region-lines[2], you can select the macro to use interactively.

Emacs has two ways of generating code from a keyboard macro, depending upon the method used to name it.

If you use kmacro-name-last-macro (bound to C-xC-kn), then Emacs generates a function from the macro, which is not directly useful for this particular purpose [1].

If you use name-last-kbd-macro to name your macro, it will be generated as a vector or string.

In either case, you then use insert-kbd-macro to obtain the code.

In fact the vector/string format is the default, so you could bypass the naming step and immediately ask for the code (typing RET at the name prompt to indicate the most recently-defined macro), and then manually edit the default name of the inserted code.

[1]: The vector form does appear to simply be embedded in the function definition, so you should be able to extract that from the code to manually re-define a macro function in vector format.

[2]: When I originally wrote this reply, I'd forgotten that this was a custom function. Sorry about that.

(defun apply-named-macro-to-region-lines (top bottom)
  "Apply named keyboard macro to all lines in the region."
  (interactive "r")
  (let ((macro (intern
                (completing-read "kbd macro (name): "
                                 obarray
                                 (lambda (elt)
                                   (and (fboundp elt)
                                        (or (stringp (symbol-function elt))
                                            (vectorp (symbol-function elt))
                                            (get elt 'kmacro))))
                                 t))))
    (apply-macro-to-region-lines top bottom macro)))

Answer 2

A simple solution is to define a macro that calls your function then use the good ol' apply-macro-to-region-lines.

Apart from that, I think that you could write a loop in a few lines of elisp that does exactly what you ask for. If you would like to be fancy, you can even prompt the user for the name of the function. I think this is a good exercise for elisp, I can help you with some pointers if you feel like you would like to try it yourself.