Goto Is Not a Horror

Re:Goto Is Not a Horror by mhitza on Wednesday March 20, 2024 @10:51PM (#39774494)

I was writing a parser for a reasonable subset of HTML5 (a full parser would actually need to include JavaScript parsing as well) and there are certain states where the same character must be reprocessed under a different parser state. [1]

I wrote my parser by iterating character by character (foreach) and when reaching those states that need reprocessing I found it nicer to jump to a goto label at the start of the foreach, after the state variable was updated.

If anyone is aware of a purely functional HTML5 compliant parser let me know, as I'd love to steal some ideas.

[1] https://www.w3.org/TR/2011/WD-html5-20110113/tokenization.ht... ctrl-f reconsume

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Re:Goto Is Not a Horror by __s on Thursday March 21, 2024 @08:46PM (#39786254)

https://jaspervdj.be/blaze Haskell

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Re:Goto Is Not a Horror by mhitza on Friday March 22, 2024 @09:09AM (#39790339)

That is a HTML generator library.

And as I've said, for HTML5 compliance you need to also parse JavaScript, see second sentence here https://dev.w3.org/html5/spec-LC/parsing.html#overview-of-th...

A good first smoke-test for HTML5 supporting parsers is the following html fragment

   <input disabled>

XML-like parsers (masquerading as having "HTML5 support") will fail if tags aren't closed or self-closing, and if there are attributes without an explicit value.

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