Need better yaml parser

[klahnakoski]

YAML is complicated, and space specific, so is prone to typos. The current query parser does not do a good job of portraying what's expected, forcing to me to use other tools to format the file correctly.

eg

from: perf,
select:
    - {value: result.stats.median, aggregate: average}
edges:
    - result.test
    - {value: repo.changeset.id12, allowNulls: false}
where: and:
    -   or:
       - {prefix: {repo.changeset.id: {$eval: rev1}}}
       - {prefix: {repo.changeset.id: {$eval: rev2}}}
    - {in: {repo.branch.name: {$eval: branch}}}
    - {suffix: {result.test: {$eval: subtest}}}
    - {prefix: {result.suite: "raptor-tp6-"}}
format: cube,
limit: 1000

result in

Traceback (most recent call last):
  File "C:\Users\kyle\.IntelliJIdea2018.2\config\plugins\python\helpers\pydev\pydevd.py", line 1664, in <module>
    main()
  File "C:\Users\kyle\.IntelliJIdea2018.2\config\plugins\python\helpers\pydev\pydevd.py", line 1658, in main
    globals = debugger.run(setup['file'], None, None, is_module)
  File "C:\Users\kyle\.IntelliJIdea2018.2\config\plugins\python\helpers\pydev\pydevd.py", line 1068, in run
    pydev_imports.execfile(file, globals, locals)  # execute the script
  File "C:\Users\kyle\.IntelliJIdea2018.2\config\plugins\python\helpers\pydev\_pydev_imps\_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "C:/Users/kyle/code/active-data-recipes/adr/cli.py", line 225, in <module>
    sys.exit(main())
  File "C:/Users/kyle/code/active-data-recipes/adr/cli.py", line 221, in main
    parsed_args.func(parsed_args, remainder, config, parser, request_type)
  File "C:/Users/kyle/code/active-data-recipes/adr/cli.py", line 67, in request_handler
    data, url = format_request(request, config, remainder, request_type)
  File "C:/Users/kyle/code/active-data-recipes/adr/cli.py", line 27, in format_request
    data = run_recipe(request, remainder, config)
  File "C:\Users\kyle\code\active-data-recipes\adr\recipe.py", line 81, in run_recipe
    recipe_context_def = get_recipe_contexts(recipe, mod)
  File "C:\Users\kyle\code\active-data-recipes\adr\recipe.py", line 43, in get_recipe_contexts
    query_context_def = load_query_context(query_name)
  File "C:\Users\kyle\code\active-data-recipes\adr\query.py", line 108, in load_query_context
    query = yaml.load(fh)
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\__init__.py", line 72, in load
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\constructor.py", line 35, in get_single_data
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\composer.py", line 36, in get_single_node
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\composer.py", line 55, in compose_document
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\composer.py", line 84, in compose_node
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\composer.py", line 127, in compose_mapping_node
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\parser.py", line 98, in check_event
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\parser.py", line 428, in parse_block_mapping_key
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\scanner.py", line 116, in check_token
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\scanner.py", line 223, in fetch_more_tokens
  File "C:\python36\lib\site-packages\pyyaml-4.2b4-py3.6-win-amd64.egg\yaml\scanner.py", line 579, in fetch_value
yaml.scanner.ScannerError: mapping values are not allowed here
  in "C:\Users\kyle\code\active-data-recipes\adr\queries\perf_tp6_compare.query", line 7, column 11

[klahnakoski]

This is the good version, I think it was the commas

from: perf
select:
- {value: result.stats.median, aggregate: average}
edges:
- result.test
- {value: repo.changeset.id12, allowNulls: false}
where:
    and:
    -   or:
        - {prefix: {repo.changeset.id: {$eval: rev1}}}
        - {prefix: {repo.changeset.id: {$eval: rev2}}}
    - {in: {repo.branch.name: {$eval: branch}}}
    - {suffix: {result.test: {$eval: subtest}}}
    - {prefix: {result.suite: "raptor-tp6-"}}
format: cube
limit: 1000

[ahal]

Yeah, there's only really two options, pyyaml and ruamel.yaml. People had previously recommended ruamel because pyyaml looked dead, but it recently got a new owner and seems active again.

Not sure which is better these days.