Add dlang codegen

[tom-tan]

This request adds a new codegen for D programming language (dlang).
It only generates a declaration for each data structure and the parser is automatically generated from the declaration with schema-salad-d.
My personal goal is to replace my hand-written CWL parser with auto-generated one.

Todo (needed to be merged):

• Add tests!
  • What kind of tests are needed to make it ready to be merged?
  • Will be added to cwl-d-auto
• Make tests passed
  • CWL v1.0
  • CWL v1.1
  • CWL v1.2
    • Except the backend YAML parser issues
• documents for usage
  • done in common-workflow-lab/cwl-d-auto

Future works of codegened parser:

• support extension fields
• support subScope
• Support YAML v1.2 spec (currently it only works in YAML v1.1 due to its backend YAML parser)
• Add workaround for https://issues.dlang.org/show_bug.cgi?id=20443
  • Generated parser may not be compiled with the latest D compiler in the case that the schema contains mutually recursive structure

---

Here is a list of known issues

• Support secondaryFilesDSL
  • need fix in both of dlang codegen in schema-salad and schema-salad-d
• cannot parse YAML v1.2 -> Added to README
  • example:

    hints:
      DockerRequirement: {dockerPull: debian:stretch-slim}

  • It is due to the backend parser. I leave it as is and add the limitation to README.

[lgtm-com]

This pull request introduces 1 alert when merging b33356a into 3059ff0 - view on LGTM.com

new alerts:

• 1 for Unused local variable

[tom-tan]

I updated schema-salad-d to make generated parser with cleaner interface.

Also, I consider to remove or rename hand-written parser in schema-salad-d because it occupies cwl module name.
IMO it is better for users if cwl-d-auto can provide parsers as cwl modules.

[tom-tan]

I updated schema-salad-d and codegen to correctly handle Expression.
I guess other improvements can be done without modifying codegen.

I will add a function to add unittest for given examples to make this request ready to merge.

[tom-tan]

Now it can support --codegen-examples!

It adds unittest block with an annotation in the end of the code.
It makes the generated code self-contained and also make the unittest controllable with third party testing framework such as silly.

[tom-tan]

Now it mostly passes all the tests for CWL v1.0, v1.1 and v1.2!

The rest of the failed tests are due to the limitation of the backend YAML parser that only supports v1.1 spec.
I will add this limitation to README.

[tom-tan]

Code cleanup is needed but it is mostly ready to review!
I updated README in common-workflow-lab/cwl-d-auto to show main features, how the parsers generated, how to load and store CWL documents and future plan.

[mr-c]

Woohoo!

Can you add a dlang entry to the table at https://github.com/common-workflow-language/schema_salad#codegen-examples ?

[tom-tan]

Added!

[codecov]

Codecov Report

Merging #623 (60f5a33) into main (7662c7f) will increase coverage by 0.03%.
The diff coverage is 84.51%.

@@            Coverage Diff             @@
##             main     #623      +/-   ##
==========================================
+ Coverage   83.39%   83.43%   +0.03%     
==========================================
  Files          19       20       +1     
  Lines        3885     4039     +154     
  Branches     1050     1096      +46     
==========================================
+ Hits         3240     3370     +130     
- Misses        414      426      +12     
- Partials      231      243      +12     

Impacted Files	Coverage Δ
schema_salad/main.py	78.14% <ø> (ø)
schema_salad/dlang_codegen.py	83.89% <83.89%> (ø)
schema_salad/codegen.py	94.59% <100.00%> (+0.25%)	⬆️

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[mr-c]

Looking great!

Can you add very minimal tests like we have for c++ in

schema_salad/schema_salad/tests/test_cpp_codegen.py

Line 17 in 7662c7f

def test_cwl_cpp_gen(tmp_path: Path) -> None:

?

[tom-tan]

I added a unittest for it!

[mr-c]

Thank you very much, @tom-tan !