3 ms·

The idea that HTML is hard to parse isn't exactly controversial; the HTML spec has a long description of the exact rules you're required to implement to parse H

The idea that HTML is hard to parse isn't exactly controversial; the HTML spec has a long description of the exact rules you're required to implement to parse HTML and it's a bunch of special cases and error handling. Certainly I wouldn't call it "heuritics" any more since everything is well specified, but equally certainly the rules are derived from heuristics that browsers implemented and are now required to maintin compatibility. I'm having difficulty unpacking your claim about a DTD "parsing" HTML5, but I find it hard to believe that a primarilly DTD-based parser would get all the rules right around, say, foster-parenting, or handling of -- in script elements, or pseudo-entities or any of the the other weird quirks that are specific to HTML and not shared with SGML languages. Perhaps you can link the code and details about the claimed test suite pass rate?

tannhaeuser 7y ago
I'm enjoying finally meeting someone to challenge my claims ;) I haven't published my test scripts yet (they're not very exciting and just extract test data and add a DOCTYPE anyway), but for the time being you can just follow the instructions given in the tutorial I linked to see whether the cases you're concerned about are covered (the tutorial also explains how to deal with other common HTML parsing issues). Nb: "<!--" in script element content isn't a problem for parsing as such and was just used to stop browsers rendering JavaScript code text during the introduction of JavaScript back in 1995 or so (see also [1] mentioning the consequences for treating script content as CDATA or #PCDATA). Predefined HTML entities are also fully supported by the WebSGML revision of SGML. Don't know about "foster-parenting", but SGML has very specific rules for tag inference to accomodate elements not allowed at a given context so I'm assuming you're referring to that (also described in detail in the linked paper below). [1]: http://sgmljs.net/docs/html5.html#script-data http://sgmljs.net/docs/html5.html#script-data

tannhaeuser 7y ago

I'm enjoying finally meeting someone to challenge my claims ;) I haven't published my test scripts yet (they're not very exciting and just extract test data and add a DOCTYPE anyway), but for the time being you can just follow the instructions given in the tutorial I linked to see whether the cases you're concerned about are covered (the tutorial also explains how to deal with other common HTML parsing issues). Nb: "<!--" in script element content isn't a problem for parsing as such and was just used to stop browsers rendering JavaScript code text during the introduction of JavaScript back in 1995 or so (see also [1] mentioning the consequences for treating script content as CDATA or #PCDATA). Predefined HTML entities are also fully supported by the WebSGML revision of SGML. Don't know about "foster-parenting", but SGML has very specific rules for tag inference to accomodate elements not allowed at a given context so I'm assuming you're referring to that (also described in detail in the linked paper below). [1]: http://sgmljs.net/docs/html5.html#script-data http://sgmljs.net/docs/html5.html#script-data