We currently have a separate branch of Cmdstan+Stan+Math that supports some additional custom functions we added to stanc2.
The functions are very specific and it probably makes no sense to try to add them to the Stan language. We would now like to move the whole thing to Stanc3 and provide the users with a similar experience as the current develop cmdstan has. Specifically the “download the stanc3 binary based on the OS” thing.
I guess one way of providing a similar experience without much overhead for us would be to ship the JS stanc3. But that means that the users need to have V8 installed or some other JS engine. Which at the end of the day is probably not so bad.
But if want we to provide the OS specific binaries we will need to build stanc3 for all three OSes.
@seantalts @serban-nicusor do we have any scripts to do that that are available for sharing. Besides that we probably only need the ability to spawn virtual machines for Mac, Linux, Windows with stanc3/ocaml prerequisites. Anything else?
I am guessing with stanc3 making adding stuff much simpler there might be more people that will want something like this. I am happy to document my process and make a wiki if anyone else would be interested in doing something similar from scratch.