In case anyone finds it useful, we (CodeCrafters) built a coding challenge as a companion to this book. The official repository for the book made this very easy to do since it has tests for each individual chapter.
Really I would love to know how parse context sensitive stuff like typedef which will have "switched" syntax for some tokens. Would like to know things like "hoisting" in C++, where you can you the class and struct after the code inside the function too, but I just find it hard to describe them in rigorous formal language and grammar.
Hacky solution for PEG such as adding a context stack requires careful management of the entry/exit point, but the more fundamental problem is that you still can't "switch" syntax, or you have to add all possible syntax combination depending on the numbers of such stacks. I believe persistent data structure and transactional data structure would help but I just couldn't find a formalism for that.
The two most popular discussions of this fantastic book:
2020 with 777 points: https://news.ycombinator.com/item?id=22788738
2024 with 607 points: https://news.ycombinator.com/item?id=40950235
In case anyone finds it useful, we (CodeCrafters) built a coding challenge as a companion to this book. The official repository for the book made this very easy to do since it has tests for each individual chapter.
Link: https://app.codecrafters.io/courses/interpreter/overview
Really I would love to know how parse context sensitive stuff like typedef which will have "switched" syntax for some tokens. Would like to know things like "hoisting" in C++, where you can you the class and struct after the code inside the function too, but I just find it hard to describe them in rigorous formal language and grammar.
Hacky solution for PEG such as adding a context stack requires careful management of the entry/exit point, but the more fundamental problem is that you still can't "switch" syntax, or you have to add all possible syntax combination depending on the numbers of such stacks. I believe persistent data structure and transactional data structure would help but I just couldn't find a formalism for that.
https://en.wikipedia.org/wiki/Lexer_hack
Make your parser call back into your lexer, so it can pass state to it; make the set of type names available to it.
One of the best resources for learning compiler design. The web version being free is incredibly generous.