Feeling gratitude towards this community. Just wrote my first #emacslisp advice ever.

(advice-add #'package-function-has-no-hook :before #'my-little-hook-function)

A small thing, but it removes friction from my org-static-blog (recommended!) workflow.

These little steps forward are what make this hobby so much fun. And—you'll just have to believe me—the confidence to bork around like this comes from being part of this community.

[EDIT: broken link removed; see thread]

#emacs #mastodon #fediverse

@jameshowell FYI if you wrote "my-little-hook-function", you could also be interested in `define-advice', which combines a defun and a advice-add into a single form. Here are two example from my init.el:

(define-advice eval-last-sexp (:before (&rest _) eval-last-sexp-pulse)
(save-excursion
(forward-sexp -1)
(let ((start (point)))
(forward-sexp 1)
(pulse-momentary-highlight-region start (point)))))

@jameshowell Also, what function from package.el did you want to modify? Your sourcehut link points to a 404 page.

@pkal Sorry! Let's try it this way. NEW BLOG POST: "My first advice! (in Emacs Lisp)"

https://jamesendreshowell.com/2026-04-04-my-first-advice-in-emacs-lisp.html

#emacs #emacslisp

My first advice! (in Emacs Lisp)

@jameshowell You ask in the blog post why Emacs Lisp doesn't have a function to return the contents of a file as a string. It kind of makes sense to me, let's see if I can explain it.

Emacs has two data structures to store text in: strings and buffers. You may think of buffers as just for showing to the user in a window to edit, but buffers also have an extensive collection of functions to work on them programatically (obviously, since every thing the user can do to edit a buffer just calls some command). I feel like Emacs in general pushes you towards using strings only for small amounts of temporary text and buffers for longer text or longer-lived pieces of text. From that point of view it makes perfect sense to me that Emacs has a function to insert the content of a file into a buffer, but not one to return it as a string: a file is likely to long and to stick around a while for you to work on it, it belongs most likely in a buffer rather than a string. The existence of `insert-file-contents` and the non-existence of a corresponding string-returning function is meant to nudge towards buffers for file processing.

@pkal

@oantolin No, I get it, in fact slinging HTML lines around in buffers and concatenating them together in buffers makes more sense—in the Emacs context. But you can see how someone (like perhaps the author of org-static-blog, and certainly naive me) would cling to string-oriented habits.

Thank you for the thoughtful, patient, illuminating answer to my snarky rhetorical question!

@pkal

@jameshowell Well, having given that answer, I should say that lots of people have probably had to write that function to get the contents of a file as a string, it probably should be included with Emacs. 😅 @pkal

@oantolin The "s" package has a function to do that, and the consequence is that people keep on reading an entire function in as a string and then doing GC-heavy list processing on the function, where using a buffer would have been more idiomatic.

I am not sure if I submitted a patch for this once, but a compromise of having a `slurp` macro could be interesting, since it would read in the file once at macroexpansion time, without making it a general replacement for buffers.

@jameshowell

@pkal @oantolin @jameshowell Btw, I don't like the slurp macro idea. There is no advantage of making this a macro - you would only lose. If slurp would exist as a function you could simply write (eval-when-compile (slurp file)). This is also a bit of a dogmatic rule: If something can be written as a macro or a function, write it as a function. But I guess many Lisp hackers agree with it.
@minad @oantolin @jameshowell There are a few advantages: It could get accepted as I presented a counter-argument based on Eli's comments in reference to a real in-core use-case, and it continues the discussion which might result in something like what you propose (which would have to be accompanied by another function that would simplify the expansion of file names relative to the current compiled file).
@pkal Sure, I see. I am very much against this kind of artifical maneuvering (or should I say manipulation) in order to achieve something. This is one thing which bothers me about emacs-devel. I would rather present my case in a clear and direct way and get a clear response. Instead of adding a slurp macro I would rather not add anything.
@oantolin
@jameshowell
@pkal And if you want to find real use cases for slurp as a function, simply grep the Emacs code base and look for potential call sites. I looked for a minute and found for example treesit-generic-mode-font-lock-query, and I am sure there are plenty of other similar potential call sites, where we could avoid repeating the with-temp-buffer/insert-file-contents/buffer-string pattern.
@oantolin @jameshowell
@minad @oantolin @jameshowell I did so yesterday, and didn't find any convincing places. In practice, most of the time I have seen packages need such a function comes from APIs that made the "mistake" of being string- instead of buffer-oriented.
@pkal @oantolin @jameshowell Oh okay. I did not expect that, and as I said, I found some places where the pattern is used. Furthermore it somehow contradicts my own experience and I've wanted a file to string function multiple times, and I claim to know enough Elisp that I can judge if it is okay to use it or if I should resort to inserting in a buffer and buffer manipulation.
@pkal @oantolin @jameshowell Also if you search around and do not find "convincing places", you are already starting with your preformed opinion. What I said or meant was different - I suggested to look around for places where the insert-file-contents/buffer-string pattern is used, just to see how often this pattern occurs, without judging if the code is perfect or not. Think about your ensure-proper-list function, which has almost no applications in Emacs and yet it ended up in subr.el.
@pkal @oantolin @jameshowell I have never missed an ensure-proper-list function while I have missed a file-to-string function, repeatedly!
@minad @oantolin @jameshowell FTR I have invested more time in this discussion than in the discussion behind ensure-proper-list. If I had know that beforehand, I would not have added the function.
@minad @oantolin @jameshowell I looked again, and did find a few instances. I think I misremembered, that most instances where this pattern appears to have been used were tests. So yes it is used, but I don't want to disregard that it isn't necessary/idiomatic most of the time.