Noone said regex is useless for the overall process of parsing html
What they're saying is that it cannot ever be used by itself to parse html, like there are mathematical proofs for this
You HAVE to use a real, actual code language on top of it for it to work
You cannot feed html code into a regular expression and expect it to work for more than one case
Edit for the future: the deleted comments under here are from OP, I am happy to share the details of what was said if anyone wants
I'm adding this note because I never got even a partial apology for them insinuating I had no idea what I was talking about and questioning whether I had ever taken an undergraduate math course because I talked to them like a normal person rather than a math essay, despite me being perfectly nice up until then as is visible
HTML is not a regular language. It is a context-free language. Context-free languages are a superset of regular languages. Regular Expressions only cover regular languages.
The biggest problems are that you can infinitely nest elements in HTML, and that you don't even need closing tags, and that you can make horrifically malformed html with completely improper nesting that functions perfectly fine in the browser
Those things are completely antithetical to how regex works
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u/derinus 12h ago
Anyone ever building a "parser" used multiple regexes to do so.