Grammar-Kit

SableCC used that visitor pattern for its outputs, and then immediately had an "empty implementation" of the interface to allow folks to subsclass the parts that were relevant https://github.com/SableCC/sablecc/blob/sablecc-4-beta.4/src... https://github.com/SableCC/sablecc/blob/sablecc-4-beta.4/src... https://github.com/SableCC/sablecc/blob/sablecc-4-beta.4/src... I think Antlr 4 does similar, I just haven't used it in as much anger because its runtime always jammed me up https://github.com/antlr/antlr4/blob/4.13.2/doc/listeners.md... I thought that IntelliJ did similarly but I am misremembering since they generate recursive descent style https://github.com/JetBrains/Grammar-Kit/blob/v2023.3/HOWTO....

I offer, again, my JetBrains GrammarKit counterpoint from the last time that assertion came up <https://news.ycombinator.com/item?id=38192427> >>> I consider the JetBrains parsing system to be world class and they seem to hand-write very few (instead building on this system: https://github.com/JetBrains/Grammar-Kit#readme ) - https://github.com/JetBrains/intellij-community/blob/idea/23... (the parser I'll concede, as they do seem to be hand-rolling that part) - https://github.com/JetBrains/intellij-community/blob/idea/23... (same for its parser) - https://github.com/JetBrains/intellij-community/blob/idea/23... and https://github.com/JetBrains/intellij-community/blob/idea/23... - https://github.com/JetBrains/intellij-plugins/blob/idea/233.... and https://github.com/JetBrains/intellij-plugins/blob/idea/233....

> Still, almost all production lexers and parsers are hand written. As a counterpoint, I consider the JetBrains parsing system to be world class and they hand-write very few (instead building on this system: https://github.com/JetBrains/Grammar-Kit#readme ) - https://github.com/JetBrains/intellij-community/blob/idea/23... (the parser I'll concede, as they do seem to be hand-rolling that part) - https://github.com/JetBrains/intellij-community/blob/idea/23... (same for its parser) - https://github.com/JetBrains/intellij-community/blob/idea/23... and https://github.com/JetBrains/intellij-community/blob/idea/23... - https://github.com/JetBrains/intellij-plugins/blob/idea/233.... and https://github.com/JetBrains/intellij-plugins/blob/idea/233....

I want to start adding support for Lua derivatives to my IDE - which adds static type checking to regular Lua. Inference, structural & nominal types, generics etc. (Luanalysis - https://github.com/Benjamin-Dobell/IntelliJ-Luanalysis/) I feel like plugin support would be best but I've no idea how that's supposed to work in the presence of a predefined grammar. There's also so many variants I don't think there's a good way to build out a composite grammar. Does anyone have any ideas about modular/extendable language parsing? For reference, I'm using https://github.com/JetBrains/Grammar-Kit.

I'm not entirely settled on that. My working approach is if you're writing a compiler, it wants to have an unambiguous grammar and shouldn't even attempt recovery. If input doesn't parse, the compiler can recommend (or just run) the linter. That keeps the common case fast and simple. The linter/fixer can have a relaxed syntax specifically designed to handle messy code and suggest corrections. That comes from a philosophy of treating error correction and user assistance as a separate task. But that's an approach I'm taking because I want to get a reference implementation together as quickly as possible. It's definitely not how modern IDEs work. JetBrains GrammarKit uses a PEG[1] because they need strong support for error recovery[2] using hints. Another interesting library is Tree-sitter[3]; it does incremental parsing keeping an AST const

Emacs, is obsolete but not for the reasons described in the article. I think the main problem is lack of smart IDE support. We can't easily define a language, a parser for it, reference resolve rules, analyze code, navigate reference, provide completion, etc. These features, not editors with a good text manipulation facilities get you the largest performance gain today. Take a look where sublime, or IntelliJ is heading to. IntelliJ, for example, has a toolkit for quickly defining support for languages: https://github.com/JetBrains/Grammar-Kit