[innguest]

Tell me about it. First thing I asked when I saw HTML over a decade ago was "Oh so you can close tags out of order?" - "Uhm, no, the last opened tag must be closed first" - "Then why do I need to say its name when closing? There's no ambiguity, it's always 'close the last opened tag', so why say its name again?". Folks at W3C must not know Lisp.

[Elrac]

I'm happy to disclaim that I have nothing to do with the mess that is the HTML standard! But if I had to guess I would say that the ending tags in HTML add a modicum of redundancy that allows for some of the crazy/creepy/smart error correction browsers have been doing for decades:

You can close your P tags or not; if you don't, the next opeining one is a new paragraph, with the previous one assumed closed. Similarly with LI tags in lists or the multiple levels of stuff in TABLE.

That makes HTML "code" marginally easier (at least in terms of effort) for humans to write and maybe also read, and for programs to error-check and correct. It's also led to waves of shitty HTML code and generations of smarter programs to guess the intentions of stupid HTML generators.

XML, being more strictly defined, could have followed the lead of Lisp and done without the closing tags. I guess people felt the need for a security blanket of closing-checkable tags, or its slightly better human-readability.

[innguest]

> That makes HTML "code" marginally easier [...] and for programs to error-check and correct.

This is a great point. It's not subjective and I'm pretty sure it's right. I hadn't thought of that. I guess there is a use for redundancy sometimes. If the point is to make the language welcoming to beginners then this decision makes sense.

I wonder, though, if they made the same mistake that the SQL people did, in devising a language with characteristics that are advantageous to some imagined target group ("non-programmers") but that ends up getting used just by programmers who then hate the training wheels.

[munificent]

> "Then why do I need to say its name when closing? There's no ambiguity, it's always 'close the last opened tag', so why say its name again?". Folks at W3C must not know Lisp.

HTML (well, SGML, in this case) was designed for humans hand-authoring large documents. If your opening tag is a few hundreds lines above the closing tag, a little redundancy is handy.

Remember, HTML is a markup format, not a data format. Tags were designed to add a bit of data to what is otherwise a plaintext document intended for human consumption.

[innguest]

We already have a solution for that:

  if whatever
    ...
  end # whatever


  (p
    ...(bunch of stuff inside p)...
  ) ; p

Now it's optional, not part of the standard, and the language is cleaner for it, while allowing for a way to help your described scenario.

Folks at W3C want to fix all kinds of non-existing problems (like HTML5 canvas when there's already OpenGL viewports).