cape VS crafted-emacs

Wow, interesting that my response is getting down voted. It seems not enough that I give away my work for free. Nevertheless I appreciate support from the community, as other Emacs package developers. The support is actually helpful. To clarify, publishing my configuration would translate into quite a bit of work, requiring separation of private and public bits.

At least for Elisp source block one can use font locking to create a custom Capf. Add cape-elisp-block from my Cape package to completion-at-point-functions. Even if you don't want to use Cape you could just copy it to your config. It is a short function.

You can use cape-history from my Cape package. This is similar to consult-history only utilizing completion-in-region instead of completing-read.

Haven't tried configuring it accordingly, but here's the docs: https://github.com/minad/cape

corfu is blazingly fast. Orderless is as well. What is not always blazingly fast is your completion providing backend. You didn't mention where your slow completions are coming from. An LSP server? Dabbrev? Maybe a remote machine? Have you combined results from various backends (e.g. using cape?). Some completions backends are unavoidably slow, others are just not well optimized.

The most straight forward solution is probably the package company-math. (that's what I use but with corfu and cape)

Some time I'll add a mixin for Cape which would make the completion stuff really nice.

If you're set on using the completion system (M-TAB) for this, you could install Cape and use the cape-abbrev command to complete your abbrevs.

Oh, of course your efforts are valuable. I didn't mean to sound discouraging in any way. The point made by /u/xenodium is good - if you have a special candidate source with special behavior, it makes sense to provide a separate lightweight Capf. In contrast, using Tempel for this purpose doesn't make much use of the actual template functionality. Tempel is only a good fit for Org blocks if you use it already anyway, as I do. There is also value in having reference Capfs around, which will be helpful when developers create their own new completion functions. This was also the intention when I created my Cape package, which comes with many simple Capfs. It is always interesting to see what other Emacs users come up with. I am thankful for such efforts - it is inspiring!

Keep an eye on Crafted Emacs which has a v2Beta release branch. It's been evolving. The v2Beta is a rewrite. It aims to provide a minimalist leg up on vanilla Emacs for new Emacs users. It's goal is to take you from first steps to a point where you have learned a great deal and built your configuration. Then you may be comfortable ditching the Crafted Emacs boilerplate configuration entirely. Think of it as a starter kit. Follow SystemCrafters on YouTube (live stream mostly) & Matrix (they are leaving Discord). Despite the live stream being lengthy, there is much to be learned as you bear witness to David figuring things out. Over time, you pickup on those techniques such as looking up a variable state, reviewing functions, evaluating snippets of Elisp in real time, etc. Also recommend, Mastering Emacs as a fantastic ebook with free updates. Once 29.1 ships, no doubt, there will be a free update to the ebook.

I'd recommend you have a look at crafted-emacs. It's an example of how far Emacs can actually go without third-party packages. Then you can add minimal packages (completion and specific tool integrations) to further enhance the experience.

For me it's quite stable except some issues I had with vertico. Anyways, I first started to rewrite my doom config into plain vanilla emacs (with org mode literate configs), and then I discovered crafted which allowed me to remove some code with commonly set sane defaults, e.g. stuff from https://github.com/SystemCrafters/crafted-emacs/blob/master/modules/crafted-defaults.el.

I have been surprised at how many people have so ardently defended only using built-ins and raw package.el and their own janky ensure methods when use-package was available and did it all better. And, it even lets you configure Emacs itself (not just packages), as well as seamlessly letting you try different package management tools like straight.el. Getting it into Emacs itself hopefully makes this a more prevalent way of showing users how to craft their own config.

If you need a staring point for configuring there's some nice light ones like emacs-bedrock and crafted-emacs, and also some fully pre-configured Emacs distributions that you can choose from (though those look harder to configure to one's personal needs to me, but I haven't tried them so wouldn't know).

I'll second https://github.com/SystemCrafters/crafted-emacs

And if you find yourself between the two extremes, perhaps https://github.com/SystemCrafters/crafted-emacs