Write a chunk parser using nom parser combinators

[helgoboss]

To finally get a robust and fast way to dive into chunks from Rust (e.g. for detecting FX parameter modulation and other stuff for which we don't have an API yet).

[GavinRay97]

Hey Benjamin, I've actually been interested in & working on this problem as well.

There's no high-performance chunk parser which is a barrier to being able to do any sort of near-realtime processing of project data from chunks.

Instead of parsing it into language-specific structs though, I've been working on converting it from not-quite-XML into valid XML, and exposing that through a C API + header.

The idea being your language (C++, Rust, D, whatever) passes the chunk or .rpp-file string into it and then the XML result is passed back in a struct field:

#include <stdint.h>

typedef struct rpp_parse_result {
  int error_code;
  const char *results;
  uint64_t len;
} rpp_parse_result;

rpp_parse_result RPPtoXML(const char *rpp_text, uint64_t length);

Then you can use a language-specific XML parser to serialize it into your language's structs/classes, which is more universal.

What do you think about this? 👀

[helgoboss]

Hi Gavin. Normalizing this to real XML sounds useful and would instantly make access to the chunk stuff easier from many languages! So I'm definitely intrigued. That said, I'm not sure if I would use it for reaper-rs because I would prefer building the parser directly in Rust (which I hope is not a big deal with a proper parser combinator library such as nom).

[baadc0de]

I've made a first pass at it.

https://github.com/audiocloud/reaper-chunks

[helgoboss]

Cool! Will try that as soon as I need to get down to chunk level again.

[GavinRay97]

@baadc0de This is awesome, thank you!