Irreal

Back in the Old Days™ ASCII was king and it was pretty much impossible to faithfully render any language that required diacritical marks or non-Latin characters. So essentially you could render English but anything else was iffy. All that changed with Unicode and especially UTF-8, which solves the compatibility issue by having ASCII and its representation as a subset.

These days, practically every application supports at least UTF-8 and Emacs is no exception. As you can see by typing Ctrl+h h, Emacs can faithfully render any language you’re apt to meet. That raises the question of how you enter those characters.

Mickey from Mastering Emacs has a nice post on how to do that with particular emphasis on dealing with diacritical marks. For me, the easiest way to deal with diacritical marks and the like is to use the TeX input method. It allows you to enter text pretty much as you would with TeX or LaTeX. But there are other input methods that essentially give you a keyboard for whatever language you need. For one-offs, I tend to use John Kitchen’s ivy-insert-org-entity that I stole from his Scimax code. It’s perfect for putting in a single diacritical or a special symbol such as the ™ above.

Marcin Borkowsi has a nice post on how to capture the current file’s location and copy it to the system clipboard. It’s just what you need for sharing information about data in a file with a colleague. By file location he means the path to the file and the line number within that file.

That doesn’t seem too hard but there are some wrinkles. First of all you want the absolute line number within the file not just the number of the line visible in the buffer. That’s pretty easy but the second problem is a bit trickier.

Sometimes, just the name of the file is not enough. It may be that two files within a project have the same name but lives under a different subdirectory. Your first thought is probably to capture the full path to the file but that isn’t optimal either. As Borkowski says, there’s no point in showing the full path on his machine. What’s needed is the path relative to the current project.

That means the path relative to the current VC repository. It’s pretty easy to get that with the vc-root-dir function. Borkowski has some code that captures the file path and line number and copies it to the system clipboard. It’s simple and can be copied and used as is or modified to meet your particular needs.

The post is definitely worth a read if only to discover how to deal with the various issues.

UPDATE [2022-06-26 Sun 14:40]: Added missing link to Borkowski’s post.

A really powerful Emacs feature for those who know a bit of Elisp in the ability to advise functions. Historically, the defadvice macro allowed the specification of code to run before, after, or around a function call. It’s really handy for modifying the action of a function without changing the function itself or getting into the details of how a function works. I have advice for 7 functions in my init.el, an indication that it’s more useful than you might think.

The defadvice macro has been obsoleted by the newer and more flexible advice-add and add-function macros. You’ll usually want to use advice-add because it works in more situations. The new macros support a finer grained specification of where the advice is to be applied.

Kaushal Modi over at A Scripter’s Notes has an excellent post that explains all the methods of specifying where the advice will operate. These methods are called “advice combinators”. Modi has what are essentially railway diagrams that illustrate the operation of each of the combinators. They’re an easy way of understanding what each of them does. He also has a summary table that describes in words how each of them works.

You should also take a look at the built-in add-function documentation that shows the new function that is created for each of the combinators.

Modi’s post is the best explanation of using advice that I’ve seen. You should definitely take a look at his post to see what’s possible.