Looking at the changelog I don't see what the current situation with erl_interface is. I've been working on some `erl_interface` code using C [2] and Nim [1], and the headers warn that older `erl_interface` headers would be deprecated in OTP 23. All the release note highlights mention is a new `erl_call` program.
Anyone know about the status / rational for the `erl_interface.h` API?
Much of the erl_interface functionality prefixed with erl_ names has been deprecated since OTP 22 and has been removed. The API has shifted to newer ei_ prefixed functions. I believe there are some new deprecations in place as well which you can find the longer form release notes.
erl_interface itself is not going away but it is evolving with the BEAM VM. Deprecation warnings should be checked when compiling code on each major release to avoid surprises as features are usually deprecated for one release and then removed in the next release each year. The erl_interface documentation should be up to date with regards to new APIs and might be worth browsing again to get an idea of the what changes look like.
Thanks! That's good info. The hardest part was that in OTP 22 the examples given used many of the deprecated erl_* apis. I was able to update the C examples (see the second link) to use non-deprecated ei_* api calls. Mostly small changes and a bit better buffer management. Though, I don't like the lack of buffer length check in even the newer ei_encode_* functions. :/ I added a 24 byte padding guessing most single item encodes are less than that, and then check variable length items for size. Still hard to use safely without a buffer overrun. I'll take a look and see what else may have changed. It's exciting seeing all the continual beam improvements!
erl_interface itself is not going away but it is evolving with the BEAM VM. Deprecation warnings should be checked when compiling code on each major release to avoid surprises as features are usually deprecated for one release and then removed in the next release each year. The erl_interface documentation should be up to date with regards to new APIs and might be worth browsing again to get an idea of the what changes look like.