Add transformation information to --info

[WardBrian]

Closes #1461.

Bikeshedding: Should this new field be called constraint, transform, or something else?

Submission Checklist

• Run unit tests
• Documentation
  • If a user-facing facing change was made, the documentation PR is here:
  • OR, no user-facing changes were made

Release notes

The --info flag will now also give information about the transformations of each variable

Copyright and Licensing

By submitting this pull request, the copyright holder is agreeing to
license the submitted work under the BSD 3-clause license (https://opensource.org/licenses/BSD-3-Clause)

[codecov]

Codecov Report

Attention: Patch coverage is 67.74194% with 10 lines in your changes missing coverage. Please review.

Project coverage is 89.53%. Comparing base (93cda2f) to head (0b59a0a).

Files with missing lines	Patch %	Lines
src/frontend/Info.ml	67.74%	10 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1462      +/-   ##
==========================================
- Coverage   89.60%   89.53%   -0.08%     
==========================================
  Files          66       66              
  Lines        9707     9734      +27     
==========================================
+ Hits         8698     8715      +17     
- Misses       1009     1019      +10     

Files with missing lines	Coverage Δ
src/frontend/Info.ml	82.75% <67.74%> (-8.91%)	⬇️

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[WardBrian]

Would be easy to revisit if we wanted to, but doesn't seem like the original request went anywhere

[andrewfowlie]

Hi Brian, was there a lack of support for this change? Let me know if I can help resurrect it.

[WardBrian]

Hi Andrew -- after you closed #1461 it seemed like there wasn't a use case for this so I never requested a code review. If it's still useful we could reopen it for discussion

[andrewfowlie]

I have workarounds, but this would be a much more elegant solution. I think having these tools to inspect a Stan model can only help algorithm developers.

If it is more or less implemented (modulo review) I would for sure appreciate it if it could be reviewed and merged. But just my opinion :)

[SteveBronder]

Kind of confused on the output format here. Is there a reason this is not "type": "matrix"?

[WardBrian]

I'm frankly not sure, but that behavior has been the case since the flag was added in #810

My guess is that it let the output be non-recursive pre-tuples, because array[N] matrix[M,K] just got collapsed to dimensions: 3

[SteveBronder]

Can you have the tests show what this looks for more complex types like tuples or arrays of arrays of matrices etc?

[WardBrian]

Can you have the tests show what this looks for more complex types like tuples or arrays of arrays of matrices etc?

info.stan already has both nested tuples and arrays of matrices, is there something specific you'd like to see?