oga

Actually, I would deprioritize c extension support. The jruby ecosystem is extremely mature and production ready. For example, database connectors exist which are pure java rather than based on c extensions. They may be better as well. Same goes for ssl (https://github.com/jruby/jruby-openssl/blob/master/README.md) and xml parsing (https://github.com/YorickPeterse/oga/blob/master/README.md) Also goes for all the json parsing, etc stuff which seems to need c extensions. Lots of systems stuff is perfectly workable using jruby (https://github.com/minimagick/minimagick/blob/master/README....) This would be a different story if you were doing jython fof example - python does not have a viable java based ecosystem. If I were you, i would NOT focus on c extensions and instead work on other stuff (like startup speed)

I used one to parse XML/HTML, CSS selectors, and XPath expressions. Parser generator in question is https://github.com/YorickPeterse/ruby-ll which is an LL(1) parser generator in Ruby. Example grammars: https://github.com/YorickPeterse/oga/blob/master/lib/oga/css... https://github.com/YorickPeterse/oga/blob/master/lib/oga/xml... https://github.com/YorickPeterse/oga/blob/master/lib/oga/xpa...

This is briefly covered in https://github.com/YorickPeterse/oga#why-another-htmlxml-par...: > Ox looks very promising but it lacks a rather crucial feature: parsing HTML (without using a SAX API). It's also again a C extension making debugging more of a pain (at least for me). Performance wise ox is generally a tad faster.

This depends on the parser implementation. For example, https://github.com/yorickpeterse/ruby-ll lets you customize the error messages as the default ones can be a little bit confusing at times. An example of this is https://github.com/YorickPeterse/oga/blob/0fd6fd8645e57ea4b2... which changes messages from "unexpected T_FOO, expected T_BAR" to "unexpected end of input, expected element closing tag". Having said that, a hand written parser _will_ beat LL(1) (or any parser generator for that matter) when it comes to error reporting, though this depends on the amount of effort a programmer put in to the error reporting.