Replace mutable structs using Accessors

[huiyuxie]

Another good way to be continued to address #2050 as @ranocha suggested.

[github-actions]

Review checklist

This checklist is meant to assist creators of PRs (to let them know what reviewers will typically look for) and reviewers (to guide them in a structured review process). Items do not need to be checked explicitly for a PR to be eligible for merging.

Purpose and scope

• The PR has a single goal that is clear from the PR title and/or description.
• All code changes represent a single set of modifications that logically belong together.
• No more than 500 lines of code are changed or there is no obvious way to split the PR into multiple PRs.

Code quality

• The code can be understood easily.
• Newly introduced names for variables etc. are self-descriptive and consistent with existing naming conventions.
• There are no redundancies that can be removed by simple modularization/refactoring.
• There are no leftover debug statements or commented code sections.
• The code adheres to our conventions and style guide, and to the Julia guidelines.

Documentation

• New functions and types are documented with a docstring or top-level comment.
• Relevant publications are referenced in docstrings (see example for formatting).
• Inline comments are used to document longer or unusual code sections.
• Comments describe intent ("why?") and not just functionality ("what?").
• If the PR introduces a significant change or new feature, it is documented in NEWS.md with its PR number.

Testing

• The PR passes all tests.
• New or modified lines of code are covered by tests.
• New or modified tests run in less then 10 seconds.

Performance

• There are no type instabilities or memory allocations in performance-critical parts.
• If the PR intent is to improve performance, before/after time measurements are posted in the PR.

Verification

• The correctness of the code was verified using appropriate tests.
• If new equations/methods are added, a convergence test has been run and the results
  are posted in the PR.

Created with ❤️ by the Trixi.jl community.

[codecov]

Codecov Report

Attention: Patch coverage is 90.90909% with 2 lines in your changes missing coverage. Please review.

Project coverage is 95.95%. Comparing base (f9c9107) to head (4357e33).

Files with missing lines	Patch %	Lines
src/equations/ideal_glm_mhd_multicomponent_1d.jl	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2052      +/-   ##
==========================================
- Coverage   96.32%   95.95%   -0.37%     
==========================================
  Files         470      470              
  Lines       37447    37466      +19     
==========================================
- Hits        36070    35949     -121     
- Misses       1377     1517     +140     

Flag	Coverage Δ
unittests	95.95% <90.91%> (-0.37%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[huiyuxie]

I cannot find the good compat version - please let the bot do this :/

[huiyuxie]

Looks good but I'm worried about the introduction of new mutable structs - not sure if it will cause problem in the future.
@ranocha

[ranocha]

Looks good but I'm worried about the introduction of new mutable structs - not sure if it will cause problem in the future.

I don't see an immediate reason why this would cause trouble in the future. We should definitely run some benchmarks to see whether there is any significant difference from this change.

Moreover, a lot of tests seem to fail.

[huiyuxie]

I have no idea why tests only failed for IdealGlmMhdMulticomponentEquations2D. Can you help me have a check please @ranocha

[huiyuxie]

I don't see an immediate reason why this would cause trouble in the future.

Like if I have to pass semi as an argument in kernels and then again non bittype errors - but I will try to avoid this case.

[huiyuxie]

We should definitely run some benchmarks to see whether there is any significant difference from this change.

Do you mean the change of mutable structs will probably affect performance a lot? Why?

[ranocha]

See

Trixi.jl/src/equations/ideal_glm_mhd_multicomponent_2d.jl

Line 35 in f9c9107

c_h = convert(eltype(gammas), NaN)

- you need to adapt the inner constructor

[huiyuxie]

Thanks

[huiyuxie]

Review please @ranocha how about the other way?

[huiyuxie]

Anyway, I prefer to make things move ahead - this issue has stalled my work for a really long time.

@ranocha Review again please and thanks for your long time support for my work - you are responsible

[huiyuxie]

Can you make this update to the next release as soon as possible - so that I can continue my work next week, thanks! Also help me update the compat version.

[huiyuxie]

Thanks :D

[ranocha]

Thanks! I will create a new release when this is merged