Support pretty-printing without inlining #include-d code

[spinkney]

When the '.stanfunctions' file has an '#include some.stanfunctions' in a different directory the auto formatter fails. One typically wouldn't include the path because it would be specified in the call to cmdstanr via include_paths = "./path_to_file".

[WardBrian]

I think the issue is a little subtle. Consider two files:

test1.stanfunctions

// defined in test1.stanfunctions
void foo(){
    return;
}

test2.stanfunctions

#include "test1.stanfunctions"

// defined in test2.stanfunctions
void bar(){
    foo();
}

Now, stanc --auto-format test2.stanfunctions fails, but that is intentional. In order to form an AST, we need the include information. Especially if you want to use --print-canonical, we need to be able to actually type-check that AST.

So, stanc --auto-format test2.stanfunctions --include-paths=/path/to/folder is what you want, but, it outputs this:

// defined in test1.stanfunctions
void foo() {
  return;
}

// defined in test2.stanfunctions
void bar() {
  foo();
}

So I think the real issue here is "support pretty-printing without inlining #include-d code". This should be doable because we keep the fact that it was included around in the location information.

[spinkney]

So I think the real issue here is "support pretty-printing without inlining #include-d code". This should be doable because we keep the fact that it was included around in the location information.

Yes, this would work

[rok-cesnovar]

I agree that by default auto-format should not inline #include. I would like to still have a way to inline the includes if requested. Not sure on what the API should be.

The use case is caching models without having to inline includes with some string processing.

[WardBrian]

I've been thinking about how the interface should be for formatting, canonicalizing, etc. I think all of these things should be optional and part of the canonicalize command, with --auto-format doing the bare minimum.

So I think we'd want something like --auto-format --canonical=includes,deprecations,parenthesis with --print-canonical becoming an alias for essentially --auto-format --canonical=[everything we can do]