For the English part of the blog, see Content AND Presentation.
2023-11-27 Clocking in to parent entries
Like many, many Emacs users these days, I’m a heavy user of Org mode. In fact, both of my blogs are written in Org. And while this very blog usually has fairly short entries, my other blog has much longer posts, divided into subsections. This creates a minor problem for me. I track time I spend on writing, but I don’t want to track time spent on individual sections of a blog post. (The reason is a bit complicated. These sections are often pretty short, and I tend to spend my writing time in chunks of 25 minutes, and I have a Beeminder goal to have at least 10 of such chunks every day, so if possible, I prefer not to divide my work time into too short stretches.)
In other words, even if I am in some lower-level heading, when I clock in, I want Org to clock in in the parent heading. Emacs being Emacs, I figured there must be a way to make that happen automatically.
It seems there are at least two ways of achieving this. One is advising the clock-in function, and the other is using one of the several clock-related hooks. It is known that hooks are the preferable way – the Emacs Lisp reference says,
If it is possible to do the same thing [modify a function’s behavior] via a hook, that is preferable.
M-x apropos-variable RET org.*clock.*hook gives several answers, and the most natural candidate seems to be org-clock-in-prepare-hook. A cursory examination of Org sources suggests that using this hook may solve my issue. So, let’s get to work!
Let’s begin with deciding how to mark headings which should be “skipped” when clocking in. Assume that I have the following file structure
* Main entry ** First subentry ** Second subentry
and clocking in when in First subentry should actually clock in the Main entry. How to tell Org this is what I want? An obvious way is to use some tag on First subentry, but I don’t like this idea. I want the “subentries” to be lightweight and easy to add, and having to remember to tag them goes against this goal. I would very much prefer to be able to mark the Main entry as the one to clock in to whenever the user starts work in any of its subentries.
So, let’s get started. (I have to admit that I needed several failed attempts to get this right.) What we need is a function which does this:
- if the current entry has the
CLOCK_HEREproperty, stay at it; - otherwise, go up one level;
- rinse and repeat unless we get to the top level, in which case get back to where we started.
Here is my code.
(defun go-up-until-clock-here ()
"Go up in Org hierarchy until an entry with property CLOCK_HERE.
If no such entry is found, leave the point where it was."
(let ((dest (point)))
(while (if (org-entry-get (point) "clock_here")
(not (setq dest (point)))
(org-up-heading-safe)))
(goto-char dest)))
(add-hook 'org-clock-in-prepare-hook #'go-up-until-clock-here)
This code is a great illustration of what you (usually) shouldn’t do. It’s extremely concise, has no comments, and – dare I say – is a bit clever. Here’s how it works.
The body of the while loop is empty, so the loop will just repeatedly run the if form until it evaluates to nil. That can happen in two situations.
One of them is when the entry the point is in has the CLOCK_HERE property (by the way, Org mode heading properties are case insensitive), the dest variable will be set to where we are, the not form will evaluate to nil and the while loop will end. This may happen during the first iteration if we happen to start in a “clock here” entry or later, when we get to one while moving up. In either case, the subsequent (goto-char dest) will do nothing, since dest will coincide with (point) – but it won’t hurt, either.
The other way the loop may end is when there is no parent heading to go and org-up-heading-safe returns nil. This means that we traveled to the top of the hierarchy of headlines without finding one with the CLOCK_HERE property. In that case, dest will be what it was first defined to be, that is, the position of point before our function was called, and (goto-char dest) will return to that place as planned.
Now the only remaining thing is to make sure that every headline which starts a blog post has the CLOCK_HERE property set. My little blog engine has the org-clive-create-page command, but I didn’t want to add code very specific to my usage there. (I suspect I am the only user of Org Clive, but maybe I am not, or I will be not.) Of course, that means that what I want is to add a hook to that command. And that is precisely what I have just pushed to master – the org-clive-after-create-page-hook variable. I added this to my init file:
(defun org-add-clock-here-property () "Add the `CLOCK_HERE' property to the current node." (org-set-property "CLOCK_HERE" "t")) (add-hook 'org-clive-after-create-page-hook #'org-add-clock-here-property)
and now I don’t have to worry about adding the CLOCK_HERE property myself anymore.
As usual, Emacs lets you have it your way.
CategoryEnglish, CategoryBlog, CategoryEmacs, CategoryOrgMode
2023-11-13 Coloring CamelCase
Some time ago one of the members of the Emacs mailing list asked about coloring CamelCase identifiers. His idea is to define two faces and have all “even” words in a camel case indentifier colored with one of them, and the “odd” words colored with the other one. The question suggests using some code from Glasses mode, which is a lesser-known Emacs feature which inserts undescores between words in camel case identifiers (and it does it using overlays, so the underscores are not really part of the buffer, they just look like this). My general rule is to avoid camel case whenever I can, but I sometimes use Glasses mode, especially when I have to deal with jsx files, where camel case is the standard.
It turns out that Glasses mode already has (almost) what is asked for. If you customize glasses-separator to be an empty string and glasses-face to be, for example, 'bold, Glasses mode makes all capital letters starting words in identifiers bold (which already helps a lot).
In order to color every other CamelCase subword with some face, however, one has to write a bit of Elisp. So, I set out to do just that, and started with looking at glasses.el.
One interesting feature of Glasses mode is that it uses overlays, which may seem a slightly controversial choice. Glasses mode is pretty old (it has at least two decades!), and overlays used to have performance issues when there were too many of them in one buffer. Fortunately, their implementation was changed in Emacs 29.1 and we no longer have to worry about that. A significant advantage of overlays in the context of Glasses mode is that they are “separate” from the text in the sense that killing text decorated with overlays and yanking it elsewhere loses them. This means that when you kill some text from a buffer with Glasses mode on and yank it in another buffer where it is off does not make the underscores (or faces for word-starting capitals) visible in the target buffer. Given that, I decided to also use overlays and not features like font-lock-keywords. This means that I can steal some code from glasses.el, too. (I could advise glasses-make-readable instead, but I think it will be more educational if I show how to build a minor mode from scratch. Note: as usual, you may freely use code shown in this blog, but this time it is explicitly covered by GPL3+, since a significant portion is copied from Emacs sources.)
All in all, it turned out that modifying Glasses mode to do what I want turned out to be pretty simple. To be fair, I ditched quite a few corner cases which are taken care for in glasses.el, like strings of continuous capital letters in CamelCase identifiers or digits (like in, say, PrintISO8601Date). I am almost sure that handling them would not be terribly difficult, though – I just treated my code as a proof of concept rather than a complete, production-grade solution.
2023-10-30 My plans for 2023 - October update
It’s been another two months since my last update, so here we are again! It’s been a busy two months for me, though some plans still are not brought to the forefront (which is a shame, I know, but I can’t do everything).
Let’s start bluntly. Frankly, I’m tired of telling you all that the time for polishing/expanding the Elisp book “will come”. I decided to (finally) do something about it. As I mentioned last time, I devote more time to writing now, so I figured that my writing schedule slot on Mondays will be devoted to the Elisp book. We’ll see how it goes. (And yes, I started today, devoting some 15 minutes to it. Not much, but it’s a start.)
It’s been almost three months since I started my other blog I keep mentioning. There are 7 articles there now (plus a few pages like About, FAQ etc.), and the average length of an article is about 2300 words (and yes, last time I gave higher numbers, but that was because I counted words in the Org mode source – which, as it turns out, contains lots of things like drawers, properties etc. – instead of the resulting HTML. Sorry for my confusion.) For the record, one post there takes me about 5 hours of work on average, which is more than I expected. It doesn’t mean that I complain – I have a lot of fun writing them – but it is time-consuming.
So, I decided to finally disclose it here, in the hope that some of you might find it interesting. Here is the story. (Beware – “it is a long tail, certainly”, as Alice said to the mouse.)
As a prelude, let me mention that I very rarely watch movies, and I basically never watch tv shows. Some ten years ago (maybe even earlier) I made a conscious decision to avoid these time sinks – I have a lot of interesting and worthwhile things to do, and watching 30-60 minutes of usually second-rate tv every week (or even a few times a week, which is possible nowadays with the streaming services) is not something I want to spend (waste?) time on.
The story proper begins early fall 2020, when I was searching for some nice music on a well-known Internet service whose name rhymes with “Blue Cube”. As is generally known, the secret algorithms of that site have a habit of suggesting videos which might or might not be related to the actual interests of the person browsing it. In my case, I got a two minute clip from a certain tv series. I knew about its existence, of course – you can’t really call yourself a geek if you don’t – but, because of my decision, I never watched any of it. For better or for worse, I clicked on it (partially out of boredom and partially out of curiosity, I suppose, which is frankly a very dangerous mix when you’re browsing the Internet!), and I was instantly hooked…
And so here I am, three years later – a devout Whovian… I decided from the get go that I don’t want to watch Doctor Who alone, so I told my (then 10-years-old and also pretty geeky) daughter about that interesting series I found, and we started watching together. (We still haven’t fully converted my wife, who only watched a few episodes with us, but we’ll get there.) Since my young geek doesn’t speak English very well yet, and the quality of translation of subtitles I was able to find on the Internet is abysmal, I set out to translate subtitles for her. (That of course explains my ongoing interest in Emacs Subed mode, which supports editing srt subtitle files.) For over two years we usually watched one episode per week (which was rather demanding for me in terms of time spent on translation!), starting with Series 5 (as every Whovian is aware, this is a very reasonable decision when you watch Who with a kid). We stopped after about three quarters of Series 7, since the final episode of that series turned out to contain a huge spoiler (ha!) for the legendary two-parter towards the end of Series 4. We moved to Rose (don’t skip Nine, as they say, and they are completely correct!) and proceeded to Series 2. Then I figured that watching School reunion would be much more fun (note: the definition of “fun” for us Whovians apparently includes crying your eyes out) if we first got to know young Sarah Jane – so we made a break and watched The time warrior and Robot (and I will certainly watch more classic Who when the time comes, these two serials were a blast!). After resuming with Series 2 and finishing the Tennant specials we got to Eleven again and are now in Utah. Meanwhile, I am translating (much slower now) Series 8 (I have just started working on Time heist). By the way, I spent almost 400 hours on translating and syncing subtitles since October 2020, and it doesn’t look like I’m close to finishing
.
Almost from the beginning I noticed that Doctor Who is far from a worthless time-killer – in fact, it touches very serious subjects pretty often, and does it in a rather surprising way. (In fact, it happened that after watching a 45-minute episode I had a serious and valuable 1-hour discussion about life with my youngling!) It is a well-known fact that Russel T. Davies is not exactly a conservative, and I suppose Steven Moffat’s view is not much different. I was therefore pretty astonished to notice that many times the message of Doctor Who is quite aligned with my personal Catholic views. After several such astonishments I started to consider sharing my general fascination with Doctor Who and my findings – some of them are staring you right in the face, but some are not very obvious. A decision to start a separate blog about Doctor Who was developing slowly, and about half a year ago I started acting on it.
As I mentioned in the previous update, I didn’t want to announce a blog with just one or two posts in it. While my regular readers should know well that I am capable of delivering new posts regularly, I wanted to have something to show before making a big announcement. Now that I’ve written seven posts (and the eighth one is under way), I feel much more confident, so here it is.
So, if you are a Doctor Who fan who likes to geek out over various minutiae, like when Rose predicts (not knowing that of course) what she’s going to be doing sixteen episodes later in her first episode, or who was the actor playing the Moxx of Balhoon and how that ties in with one of the main topics of The end of the world, or how Gwyneth plants seeds for the events of Father’s day in a seemingly throwaway comment, or how not one, but three characters in Dalek mirror various qualities of the Doctor’s, or how The long game gives me very strong Biblical vibes – head on to my second weblog, called Crimson Eleven Delight Petrichor. I am publishing a post there every other Saturday until I complete Series 1, and then I will decide what to do next. On the one hand, there are many later episodes I’d love to dive deep into. On the other hand, it takes quite some time, and it may turn out that I’ll have to slow down considerably. You can help me make the right decision by going to the Supporting the author page and following instructions there!
As for technicalities, the CEDP blog is (obviously) powered by Org Clive, and I have to say that it works wonderfully. One of the features I built into it are “publication dates” – every page has one, and when you build the site, you are asked about a date (with the default being today). Then, every post scheduled for later gets skipped. This way I can prepare drafts of future posts and not worry about them accidentally being published too early. I even have an idea to further enhance my workflow. At some point in time, I’m going to set up a minimal Emacs installation and a Git repository with the blog on the machine it’s hosted on, and add a Git hook so that every time I push any change, the new version of the site is generated directly in the public/ directory. Also, I plan to set up a simple cronjob to generate the site every 24 hours. This way I won’t even have to do anything on Saturdays when a new post should be published – it will just happen, assuming the post is written and pushed to the server in advance (so far, I almost always finished these posts at least a few days earlier than they were scheduled, and I hope to keep it that way!). I know of course that large and advanced blog engines like Wordpress have such functionality built in, but I’m glad it’s so easy to replicate in my tiny piece of code.
Speaking of the machine the blog is posted on – it is a very minimalistic VPS, offered by a small company located in southern Poland. If you want to rent a cheap GNU/Linux server in the cloud for some little (and maybe even not so little – they also have beefier machines) side project, check out mikr.us (note: the site is in Polish only). So far I am very satisfied with it, and I don’t expect that to change.
Ok, enough about this project of mine (at least for now). I kept it in secret for quite a while, so please forgive me for spending considerable time to finally reveal it. It definitely falls into “labor of love” category, so I could write on and on. Also, don’t hesitate to comment here or send me an email (there are no comments on CEDP, a seemingly strange choice which is explained in the FAQ page) if you are a fellow Whovian and want to tell me about it (even if that comment would be just “Fantastic”, “Allons-y”, “Geronimo” or a picture of your eyebrows).
For now, my writing time is fully used up – between this blog, my other blog, and another project I’m now doing with an old friend, there is not much time left. In fact, there is no time left. This means, that the web extensions book is now officially postponed indefinitely. (Mind you: that does not mean “canceled”.) If you counted on that book being written soon – I am really sorry. These were plans, not promises, and apparently no plan survives first contact with the enemy. But then again – telling me in an emal that you cant this book earlier may influence my decisions in 2024.
As for the other projects – as said above, I am now working on some math-related stuff with a friend and still devote just a little time to some programming side projects. The rest of the time is taken by personal and family commitments, which seem to need a bit more time from me these days (not that it’s a bad thing!).
And that’s it for today. I’m going to make one last 2023 update in about two months (and make it a summary of the year and maybe some sneak peek into 2024). I still don’t know if I’ll be doing these updates in 2024, too – probably yes, but more rarely (since the frequency of publishing here decreased twofold, I don’t want to “waste” precious “post slots” on them too often). Until then, see you on both my blogs, and have a good rest of the year!