Represent elements of choices as pointers

[marshallmoats-wk]

PR Details

Description

(Note: this PR includes the changes from #102. That PR should be merged before this one.) This PR marks elements as optional when some ancestor element is a choice. In Go, this allows such elements to be omitted from XML serialization when that element was not present in the choice (i.e. when the pointer is nil).

The other (quite minor) change is that, in Go code generation, when an element is both plural and optional, this would generate a field of type []*T, where T is the generated Go type of the element. I've changed it so that it will generate []T instead--the optional-ness of this element is best represented by an empty slice, so pointers are unnecessary. However, for complexTypes, T will be generated as a pointer anyway, so this doesn't change anything in such cases. This was already done in a previous PR, I was not aware.

Related Issue

Motivation and Context

How Has This Been Tested

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[xuri]

Code conflicts should be resolve.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.92%. Comparing base (ca26c15) to head (58ddaf3).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #105      +/-   ##
==========================================
- Coverage   81.93%   81.92%   -0.01%     
==========================================
  Files          37       37              
  Lines        1871     1870       -1     
==========================================
- Hits         1533     1532       -1     
  Misses        246      246              
  Partials       92       92              

Flag	Coverage Δ
unittests	81.92% <100.00%> (-0.01%)	⬇️

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[marshallmoats-wk]

@xuri Let me know if there's anything else that I'll need to do before this can be merged.

[xuri]

LGTM, thanks for your contribution.