Irreal

Here’s a small problem to think about: how many working days are there in this month or, more generally, between any two dates? “Working days” means Monday through Friday minus holidays. It’s not a hard problem but think how you would solve it. There’s certainly no formula like that for calculating the day of the week on a given date but even consigning yourself to brute forcing the calculation there’s no obvious trivial solution.

Marcin Borkowski (mbork) has an interesting post that details his solution. His solution is for the number of working days in a given month but wouldn’t be too hard to generalize to the number of working days between two arbitrary dates. His method is truly brute force. He pushes the weekend days onto a list, adds any other days off such as holidays occurring during the month, counts the size of the list, and subtracts the result from the number of days in the month. The extra days off are specified manually so that he can add personal days off and account for differences in holidays between countries.

As Mbork says, the real lesson from all this is how flexible Emacs is and what a nice environment it provides for writing little helper functions. Take a look at his post and see if you don’t agree.

Álvaro Ramírez continues to roll out new examples of applications for his dwim-shell-command framework. His latest offering is three functions that, given a photo:

1. Display the EXIF information
2. Displays the location of where the photo was taken in the minibuffer
3. Displays the location of where the photo was taken on a map

All the heavy lift is done by ExifTool. As usual with dwim-shell-command functions, the actual functions are just a little glue code that calls ExifTool and displays the results. In the case of displaying the location on a map, the lat/lon is first extracted from the photo by ExifTool and then used in a call to OpenStreetMap in the browser. It works with both macOS and X-based display systems.

The three functions, along with all the others are available in Ramírez’s dwim-shell-commands.el file. They’re all simple and easy to adjust to your particular workflow. Take a look at Ramírez’s latest post for a nice example of the power of this framework.

Leo Vivier announces on the Emacs subreddit that the 2022 EmacsConf is scheduled for December 3^rd and 4^th. The conference will be live streamed so you needn’t travel to participate. Most of us won’t be able to watch the whole thing live but here’s a schedule in case you’re particularly interested in a particular talk.

The conference guide doesn’t say (that I can find) whether or not the recordings of the talks will be available for later viewing but they almost certainly will be. The organizers are promising more information as the conference itself approaches.

UPDATE [2022-11-07 Mon 11:32]: Sacha notes in the comments that they will be posting the videos.

Most Irreal readers know that Emacs offers the Hyper and Super modifier keys for use in keybindings. Less well known is that there is also an Alt key. It’s not the Alt key that appears on most modern keyboards that Emacs usually maps to Meta but a separate modifier. Sadly, we no longer have the Space-cadet keyboard so special effort is required to map them to existing keys. Usually, this means giving special meanings to the right modifier keys and perhaps the Window key if you have one.

This isn’t too hard on macOS but can be tricky under X. Over at Emacs Notes there’s a very nice post that shows you how to use the xkb file to set up all these keys. It’s very fussy but only needs to be done once. After that, you can enjoy the full set of Emacs modifier keys.

In the Emacs Next Step branch there are variables to set up the modifiers so you can simply add them to your init.el, possibly conditionally evaluated, to make your configuration portable to other OS environments.

The utility of doing all this may not be clear but I use Hyper as a modifier for many operations—either existing or homegrown—that aren’t already mapped. Once you have these keys, you’ll find all sorts of uses for them.