Learning to write PPX extenders: some links

Hi! This is just to signal boost a couple of PPX extension examples, for extenders specifically, that I found useful in my learning. Sorry for not selecting others, I stumbled upon these.

  • Blog post by Nathan from Tarides is the go-to tutorial that I only discovered today. But its section on error reporting via raise_errorf is outdated, the documentation recommends emitting an error extension whenever possible.
  • ppx-monoid is recursively translating the expression parts of interest while keeping others unchanged.
  • tensority is reinterpreting operators globally.
  • pacomb is an example of “mappers”, applying matching changes anywhere in the expression.