The question still is: why is CSS becoming a programming language? And who decides on this, anyway?
Why? Because of enormous JS bloat. Pure CSS solutions are more performant and backwards-compatible (don't raise exceptions which abort the code).
Who decides? CSS Working Group.
What I see in the SO answer is an interface for Rule 110 with an additional set of instruction (written in a natural language) for the user to execute manually. So you can use CSS + HTML to create an interface for a Rule 110, which is then written in a natural language around that interface. The answer even states that (very relevant) caveat.
> [...] so long as you consider an appropriate accompanying HTML file and user interactions to be part of the “execution” of CSS.
> The formal definition (simplest) of Turing Machine is simply a tuple of states set, symbol set, initial state, accepting states set and a transition function. There is no crank in it. By computation we mean somebody needs to apply the transition function faithfully on the tape which is exactly like the clicking in this case. More formally, a model of computation can be viewed as a set of rules somebody needs to follow to do the computation. In that sense, I think CSS is Turing-Complete.
There is even a "CPU emulation" in pure CSS: https://dev.to/janeori/expert-css-the-cpu-hack-4ddj and pure CSS fetch: https://dev.to/janeori/100-css-fetch-and-exfiltrate-512-bits...
Efficient evaluation of expressions is a solved problem.
Having conditionals would actually improve performance because you can use fewer rules.
But instead of a single unified standard library for the industry we got a sprawling, ludicrous mess of multiple poorly thought-out semi-compatible technologies, with an associated sub-industry of half-baked fixes and add-ons.
The context is also lost. Javascript was famously coded in a day or whatever and called 'javascript' not ecmascript as marketing to compete with Java. Besides that well known case there's presumably thousands of esoteric business decisions made back then which shaped the "sprawling, ludicrous" landscape, and which are now lost to time.
Yes, the web should have always been a programming language. And the flying cars of 23xx should have never used a z-debuffer doodad.
I'm glad the transition to mobile web accelerated on more battery efficient GPUs was possible due to the model instead of Alan Kay's idea that websites should render themselves, where each website would have needed to be upgraded for GPU support for compositing.
I mean looking at the mdn docs it's just a replacement for regular other syntax https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/V...
So instead of having a css for x which defines e.g. dark mode and light mode separately, you can now define it via a single css rule.
Where previously the "tree" forked at the beginning and attributes were set multiple times, depending on various criteria - now you set it once, and evaluate it's value depending on criteria
div {
background-image: if(
style(--scheme: ice): linear-gradient(#caf0f8, white, #caf0f8);
style(--scheme: fire): linear-gradient(#ffc971, white, #ffc971);
else: none;
);
}