Of course it is, it is a collection of instructions that can be executed by a computer to perform a specific task. In this case the task is to display some data on a screen in a specific way. We need to stop arguing that HTML is not a programming language, it's silly and serves no purpose.
In most non-technical discussions like this, it's only serving the purpose of gatekeeping, as if people who work with HTML or CSS are not really programmers. That's nonsense and should be rejected.
I do think that, in specific technical contexts, a useful distinction (though still fuzzy on the margins) can be made between programming languages and markup languages.
> In most non-technical discussions like this, it's only serving the purpose of gatekeeping, as if people who work with HTML or CSS are not really programmers. That's nonsense and should be rejected.
Of all the things you can say about an HTML file, the one thing you can absolutely not say is that it is a collection of instructions. It is literally a declarative description of components to be rendered.
I also did not say HTML is not a programming language.
> declarative description of components to be rendered.
Doesn't the "to be rendered" part make it instructions? Its like there are two labels for a bottle of poison: "poison" and "poison: do not drink". But the label that says "poison" is of a shape, color, and design that is commonly understood to be a label that tells the reader not to imbibe the contents of the bottle to which it is attached.
If you define a "program" as "a series of instructions to perform a task, where the instruction set is Turing Complete", then your statement is tautologically correct based on your definition. A much more general definition is simply "a series of instructions to perform a task". Do you feel that the former definition of the word "program" is the only one worth using?
As an example: if you use a Game Maker application to construct a video game where your inputs are the graphics, the level design, and some basic scripting to connect them up, is the resulting output "not a program" because the input scheme that you used in order to define its behavior was not Turing Complete? You could make an argument that, in the context of Quines, this isn't relevant because the Program is not outputting its own source code but only the top-most layer of its definition, but then again that's true at some level for any Quine not written in machine code (and even then it'd probably be missing much of the OS / display drivers / etc.).
Edit: removed an example about "programmable TV remotes" because it wasn't a very good example, and added a note about Quines.
Limitations of those instructions is the key aspect. You couldn't use any English or natural language expression for example. It might seem obvious but complexity of those instructions is what makes the language abstract. Having complicated instructions isn't always desireable though e.g. the CISC vs RISC debate.
To be clear, I am in complete agreement with every point you've made explicitly in this thread. What I do not agree with is the following implicit claim:
An HTML file cannot be a Quine because an HTML file is not a program because HTML is not Turing Complete.
At some level probably a meaningful distention, like you wouldn't decide to create a neural network in HTML alone. But from a high level HTML is a language used in programming, generally with other languages to create distributed multi-platform computer programs.
My point is let's stop being so pedantic in the soft spaces. This isn't a discussion about "should I use HTML to write my kernel?"
Markup language is a useful category, but the dividing line isn't "Turing complete". Some traditional markup languages are Turing complete (certainly postscript, possibly troff?), while some interesting academic programming languages carefully avoid being so (eg. Charity).
While certainly the class of Turing-complete languages is an important one, I think it's a mistake to treat that specific class as the definition of “programming language”.
In my opinion: JSON is not a programming language when it's used as a data transport format; however, it can represent code which an interpreter could evaluate as a program.
To be pedantic, we can define a non-Turing-complete subset of a Turing machine's instruction set, and pass combinations of these instructions to the machine, and that could still be called a program.
HTML by itself can't receive input or create output. It is input/output. It can't run or be executed. It doesn't transform state or even have state. It's not Turing complete.
HTML with either CSS3 or JavaScript is definitely a program, though.
You can write an entire game like super mario in an html file. Is a super mario game not a program? And no, this is not an archaic way to use html files, it is pretty common to share smaller games as html files. You play them by loading them into your browser.
Remember that html files are not just html. The way we use them today they are fully functional programs.
You are arguing against a statement I didn't make. Look back at the last sentence of my original comment[1] where I distinguished HTML from HTML+CSS3+JS.
It seems we agree that HTML (a language, not a file that also includes other languages) cannot create a game like Mario or even Pong.
Except that you can "run" (display) an HTML document without ever sending any HTTP requests. The HTML has no power to send one. It just tells you what happens if a user clicks a UI element.
Saying that HTML can send HTTP messages is like saying that HATEOAS API responses[1] can send HTTP messages. They can't without a separate program (written in a non-HTML language) to interpret the HTML and send the message.
