I think the only meaningul distinction is between a general purpose programming language, and a domain-specific programming language.
It seems to me that HTML is the latter.
Qualifying it as a "true" or "false" programming language (or Scotsman, wink wink) doesn't really matter, however I do think qualifying it as a DSL does add meaning.
Sure, but seems like semantics to me.
Is it a markup language or a domain-specific language?
Isn't a markup language a domain-specific language?
In my opinion, semantics matter. Granted, only up to a point, but I personally draw my own line there. DSL is good enough for me, that's all I'm really saying, I'm not trying to solve a metaphysical issue.
You could say the same about any categorisation. There is a reason why you are a human, a mammal, an animal, a life form. Those might seem unnecessary labels but they tell us what you do, what you are capable of. Same with languages.
There is a point at which all meaning is lost in detail, and that is in general, not where you want to be. Hence my approach to try and find a lowest common denominator that lessens my own cognitive load.
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