[red2awn]

Yeah I am currently writing a compiler, turns out for useful error messages my parser should accept a superset of my language, then validate it afterwards.

[nsajko]

Maybe you should check out the Menhir parser generator instead.

Some links:

http://gallium.inria.fr/~fpottier/menhir/manual.pdf

https://semantic-domain.blogspot.com/2015/11/error-handling-...

https://baturin.org/blog/declarative-parse-error-reporting-w...

[mhh__]

The way the D compiler does it is by parsing until it finds an error, marking the node as "poisoned" then walking back up until it can keep going.

It seems to work although I would include a "fail early" flag just to help with enormous error messages (if you apply the principle to sema as well)