This is a nice resource. Many moons ago when I first heard of Kakoune [1], I wanted to write some of my own plugins for it. Whether or not the philosophy has changed, back then it was 'just use shell scripts and make sure they're POSIX compliant'.
That's when I learned about things like named pipes, the `mkfifo` command, and that it does take quite a lot of conscious effort to not accidentally include a convenient bashism. That said, there was nothing stopping you from writing the main functionality in another language and just shelling out to it. No need for the editor's config language to include primitives to do most of what a programming language would give you.
The first Korn shell from 1988 far predates the POSIX shell, and is a much richer language (from which BASH has stolen very much).
As I understand it, ksh88 had to run on a 286 processor with 64kb data and instruction (segmented memory). The code required to do this was byzantine and frightening to maintain.
Because all of these features could not be included in maintainable code on systems with very low memory, the POSIX shell eviscerated the ksh88 language standard.
Surprisingly, checking the HP-UX man page (man sh-posix) gives most ksh88 functionality, which is definitly not in the Almquist shell (AFAIK the most popular POSIX shell).
It is unfortunate that the POSIX shell had to take such a large step backwards when a far more powerful language predated it, but the reasoning is clear (and mostly centered on Xenix on a 286).
Isn't dash the more popular/common POSIX shell nowadays? Not sure how to go about evaluating this claim.
Dash is the Almquist shell.
Most shells needed updates to fully-conform with the POSIX standard. The wiki mentions that the Almquist shell did not implement a "test" program that fully conformed.
The sh-posix on HP-UX also had subtle changes to the ksh88 source to bring it into compliance (but this shell still supported arrays and coprocesses).
* https://www.in-ulm.de/~mascheck/various/ash/
And Wikipedia does not say that. It says that the Minix Almquist shell, specifically, had a non-conformant test utility. The Almquist shell did not, after all, have a built-in test command at all to start with, so the standard conformance of that utility wasn't a matter for the Almquist shell.
Once again Wikipedia is wrong, because Thomas Dickey's original page that purportedly supports this claim points out that the Minix test command was an external command and not part of the Almquist shell. M. Dickey even pointed to the source code for the external command on GitHub.
* https://invisible-island.net/autoconf/portability-test.html#...
* https://github.com/Stichting-MINIX-Research-Foundation/minix...
* https://commons.wikimedia.org/wiki/File:Don't%20abbreviate%2...
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