Irreal

I’ve long been an enthusiastic Yasnippet user and have written about it a few times. Its canonical use case is in programming to fill in primitives such as the for loop in C or a class definition in Python but I rarely use it that way. I mostly use it with Org files to do things like create the header for blog posts, add boilerplate, do simple expansions like latex → LaTeX, insert daily checklists into my journal, and add code blocks to my blog posts.

These are all pretty simple operations that don’t begin to use all that Yasnippet has to offer. Jack of Some has an excellent video on how to superchage Emacs with Yasnippet. He does, of course, cover simple text substitutions but he also shows how to use its more advanced features.

One particularly nice example is his expansion of a Python class definition. As he adds arguments to the definition, the snippet automatically adds the code to initialize the instance with the arguments’ values. More generally, he shows how you can embed Elisp into the snippet template to do non-trivial things like insert the name of the current file into the text.

One thing I didn’t know how to do was to add “global snippets”. Usually snippets are only active for a particular type of file but it’s possible to have snippets that are always available. Take a look at the video to see how to do this.

The video is two years old but I just came across it. It’s definitely worth a few minutes of your time. It’s a few seconds over 12 minutes long so it should be easy to fit into your schedule.

Sooner or later almost every Emacs user discovers Dired and becomes a dedicated—or even fanatical—user. It’s basically a file manager but embedded within Emacs. As I’ve mentioned before, I tend to be an old-timey sort of guy so my natural inclination is to do my file manipulations on the command line just as I have for years but even I am a Dired convert and do essentially all my file work with it.

Nicolas Martyanoff is pretty much the same but he has a problem with the default listing. His complaint is that there’s a lot of unnecessary information, often formatted in an inconvenient way. That would be a minor annoyance except that it often causes the (arguably) most important datum, the file name, to wrap and be difficult to read.

Fortunately, Dired is reasonably configurable by setting various variables. Martyanoff took advantage of this to produce a nicer Dired listing. The dates are all in ISO format and file sizes are given in bytes rather than the generally useless number of file blocks. The resulting listing is more pleasant and easier to read as you can see from Martyanoff’s post.

Dired, of course, gets its information from ls so getting a better date and size format just means changing the arguments to ls, which are specified in one of the above mentioned variables. Sadly, the required changes are specific to the GNU version of ls so you’ll have to use it.

Martyanoff doesn’t mention if this effects Wdired but there’s no reason it should. That would be a showstopper for many of us. Other than that, this seems like a nice change that might be worth implementing. There is just a bit of Elisp involved so it’s easy to try it out and experiment with it.

If you’re a researcher or even a college student writing research papers, one of the arduous tasks waiting for you is the literature review. You probably start with a single paper and want to find related papers that address the same problem. In the past, this was a hard problem but the digitization of papers has made it easier.

John Kitchin has made it easier yet. I’ve written before about his excellent org-ref, a package that helps organize and automate references. The org-ref package has always supported literature review but recently Kitchin has added some new features that take advantage of OpenAlex to find

• Similar papers
• Citations of the paper
• Papers listed in the references

It’s an excellent addition that makes literature review a little less onerous. The reason org-ref is so useful is that Kitchin wrote it for his own use as a researcher and it therefore meets real needs as opposed to theoretical needs that someone not involved with research might imagine. If you haven’t already watched Kitchin’s video on org-ref, be sure to take a look. If you’re a researcher it will be enough to make you take up Emacs. It’s a truly amazing piece of software.

I’ve long been a fan of Kitchin’s work and this latest addition to org-ref is a good reason why.

It’s a commonplace that one of the features of Emacs is that everything’s a buffer and that this is a feature. Marcin Borkowski (mbork) has a short post that demonstrates the power that this brings.

The TL;DR is that he had a long file name comprised of several words one of which was hard to spell correctly. He wanted to check if he’d spelled it correctly and, if not, correct the spelling. Think for a moment how you’d solve that problem.

If you’re not an Emacser, your solution probably involves somehow isolating the file name, extracting the word in question, running it through a spell checker, and finally renaming the file either manually or through a file manager.

Borkowski’s solution was much simpler: he leveraged the fact that like everything else in Emacs, the Dired display is actually a buffer and therefore subject to the usual Emacs editing manipulations. He simply turned on Dired buffer editing, ran spell check on the word in question, and saved the results. All without leaving the comfort of Emacs. Take a look at Borkowski’s post for the details.

As Borkowski says, no other editor has this level of integration between the various subsystems. Buffers, like many things in Emacs, are easy to take for granted but they are the source of a lot of power.

As many of you know, I’m a big fan of Emacs Calc and use it as my calculator of choice whenever I’m on my laptop. Calc has robust conversion capabilities—to convert miles to kilometers, e.g.—but it can be a bit tricky to use.

Not to worry. Nicolas Martyanoff has a very nice post that explains how to use units with Calc. You can do things like add meters to centimeters and simplify the results, convert between units, and even define custom units.

The hardest part for me is remembering the unit abbreviations. Calc, of course, will list them for you and you eventually learn the ones you use regularly. One odd thing about Calc is that the conversion between temperature units—Fahrenheit to Celsius, say—doesn’t work the way you think it would. If you try to convert 32°F to Celsius, you get 17.7777777778°C instead of the expected 0°C. The manual explains this as Calc treating the temperatures as relative temperatures so a change of 32°F corresponds to a change of 17.7777777778°C. What’s really going on, of course, is that most conversions involve a simple multiplicative constant whereas with temperatures there’s also an additive constant. Fortunately, Calc has a separate command (u t) to do temperature conversions.

If you’re a Calc user or just want a handy way of making conversions, take a look at Martyanoff’s post. It’s short and well worth a couple of minutes of your time.

One of the really nice features of Emacs is its builtin help system, which often results in Emacs being described as the self documenting editor. Experienced Emacsers usually take it for granted but it’s really a wonderful thing. There’s no need for storing or losing manuals; it’s all there all the time as part of the application.

Old hands take advantage of this documentation without thinking about it but n00bs may wonder how to get started. Davide Mastromatteo has an excellent tutorial on how to access the Emacs help system and use it effectively. He starts by mentioning the builtin tutorial and recommends that everyone go through it at least once. Fortunately, Emacs will remember where you left off so you don’t to complete it in a single sitting.

Next he mentions that the Emacs manual is also built in (in info format) and easily accessed with the Ctrl+h r sequence. I find it more convenient to access the Web version of the manual but it’s nice to have it available when I don’t have Internet connectivity.

From there Mastromatteo moves on to the three help commands most of us use the most: describe-key, describe-function, and describe-variable bound to Ctrl+h k, Ctrl+h f, and Ctrl+h v respectively.

Finally, he mentions the appropos command (Ctrl+h a) to do fuzzy searches of the help commands. If you’ve been using Emacs for a while, you’ve doubtlessly internalized these commands by now. If you’re new to Emacs, Mastromatteo’s post is definitely worth your while.