Feature/3161 parse tuples json

[mitzimorris]

Submission Checklist

• [x] Run unit tests: ./runTests.py src/test/unit
• [x] Run cpplint: make cpplint
• [x] Declare copyright holder and open-source license: see below

Summary

Updates json parser and data handler to allow tuples, including tuples of tuples, arrays of tuples, tuples of arrays of tuples, etc.

Intended Effect

Allow users to supply init files of JSON data corresponding to Stan program tuple variables.

How to Verify

Unit tests.

Side Effects

Parser allows nested objects.

Documentation

N/A

Copyright and Licensing

Please list the copyright holder for the work you are submitting (this will be you or your assignee, such as a university or company): Columbia University

By submitting this pull request, the copyright holder is agreeing to license the submitted work under the following licenses:

• Code: BSD 3-clause (https://opensource.org/licenses/BSD-3-Clause)
• Documentation: CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

[mitzimorris]

ready for re-review.

[mitzimorris]

re-review?

[mitzimorris]

I broke the unit tests for ill-formed JSON which the handler should detect and report into from file "json_data_test.cpp" into a new test file, "ill_formed_json_test.cpp", and then added more tests for redefining tuple and array of tuple vars.

[mitzimorris]

Added logic to ignore top-level entries with names that aren't legal Stan varnames and corresponding unit tests. Ready for re-review.