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Comment by s_dev | Hacker News Reader

It's not programming language because it's a markup langauge.

It's not turing complete. There are limits to the types of computation that can be performed with it.

It's not silly -- it's a meaningful distinction.

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.

>"a series of instructions to perform a task"

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.

An html file doesn't contain just html.

If programming languages need to be turing complete, do you consider this language a programming language?

https://github.com/ainfosec/crema

Also, you can generate RSA key pairs using HTML: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/ke...

IMHO, the better mental model is that HTML is a declarative programming language that is very abstract.

HTML has sections for data and code just like most other executable files. The code parts in an HTML file are typically in <script> sections.

Why do you think it supports <script> tags? To allow you to extend the functionality where HTML is clearly limited.

Adding two numbers in HTML might be expressable but clearly it's much easier in Javascript.

Lots of historians consider programmable looms to be the first computers, even though they're not Turing-complete.

Cellular automation is Turing-complete, but is not a program.

Turing-complete is a fun thing to talk about in college theory classes, but has limited practical use outside of academia.

It's only real use outside of academia is getting investors on board with your cryptocurrency

And—apparently—gatekeeping what is a "real" programming language.

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”.

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