Ruijie Yu <rui...@netyu.xyz> writes: > Hi Arthur, > > Please excuse my brevity and semi-random line of thought, as I’m replying on > mobile right now. See below. > >> On Feb 10, 2023, at 23:11, Arthur Miller <arthur.mil...@live.com> wrote: >> >> >> Based on a Reddit thread: >> >> https://www.reddit.com/r/emacs/comments/10xhvd8/a_little_readstring_utility_using_an_org_mode/j7xziao/?context=3 >> >> I did a small experiment to see if I can re-use org-capture, to just capture >> a >> string from a buffer, without actually writing to any file. >> >> My plan was to just let-bind org-capture-finalize with cl-letf: >> >> #+begin_src emacs-lisp >> (defun my-read-string () >> (cl-letf (((symbol-function 'org-capture-finalize) ;; C-c C-c >> (lambda (&optional _) (interactive "P") (buffer-string))) >> ((symbol-function 'org-kill-note-or-show-branches) #'kill-buffer)) >> ;; C-c C-k >> (let ((org-capture-templates '(("s" "string" plain (function ignore))))) >> (org-capture nil "s")))) >> #+end_src > > Based on my somewhat-limited experience with CL (and elisp), I have never seen > this particular type of letf structure. What I am used to seeing and writing > is > the following:
It uses "place" or "field" to set the symbol binding, as in setf or incf. You can read more on SX: https://stackoverflow.com/questions/39550578/in-emacs-what-is-the-difference-between-cl-flet-and-cl-letf > (cl-letf ((f (x) (1+ x)) > (1+ (f 2))) > ; => 4 > > In particular, IIUC, I don’t think you would need symbol-function here. Maybe > you can learn more from the docstring of cl-letf than me trying to drain my > memory on this topic without reference. > > Also, in the code snippet you provided, what *should* org-capture-finalize > be? A function that can be called like this: > > (org-capture-finalize arg1 arg2) > > ? Or a variable containing a function (reference) that can be called like > this: > > (funcall org-capture-finalize arg1 arg2) > > ? In the former case you might be able to use cl-letf, and in the latter > case you should use let with a lambda value. > >> Unfortunately, that does not work. Regardless of binding, and if I used >> cl-letf >> or cl-flet or cl-labels, or old let, or something brewed on the internet, the >> binding org-capture see for org-capture-finalize, is the original one from >> org-capture.el. >> >> My second experiment was to abstract the finalize function into a funcallable >> fariable in org-capture.el (I have patched org-capture.el with this): >> >> #+begin_src emacs-lisp >> (defvar org-capture-finalizer #'org-capture--default-finalize) >> >> (defun org-capture-finalize (&optional stay-with-capture) >> "Finalize the capture process. >> With prefix argument STAY-WITH-CAPTURE, jump to the location of the >> captured item after finalizing." >> (interactive "P") >> (funcall org-capture-finalizer stay-with-capture)) >> >> >> (defun org-capture--default-finalize (&optional stay-with-capture) >> "Default implementation for org-capture finalizer function." >> >> ;; this is the original org-capture-finalize just renamed to >> "default-finalize" >> ) >> #+end_src >> >> So I could then have something like this (never mind C-c C-k function being >> removed): >> >> #+begin_src emacs-lisp >> (defun my-read-string () >> (let ((org-capture-templates '(("s" "string" plain (function ignore)))) >> (org-capture-finalizer >> (lambda (&optional _) (interactive "P") (buffer-string)))) >> (org-capture nil "s"))) >> #+end_src >> >> However I see that the binding for the org-capture-finalizer, in capture >> buffer, >> is still the default 'org-capture--default-finalize' and not my lambda. > > I guess this answers part of my question in my previous paragraph. Is > org-capture-finalizer defined via defvar? If so, does it help if you put an > empty defvar before the let binding? If not, maybe someone actually using > Emacs > right now can be of more help here. These were two different examples; one that let-binds the function 'org-caputre-finalize', via cl-letf and the latter one that was completely different in which I have defvared a symbol so I can let-bind it as a variable. > If not, maybe someone actually using > Emacs > right now can be of more help here. Don't worry; thanks for the help anyway! /a
