Discussion on the Next Steps for Module Development

[denghuilu]

Background

In response to suggestions from some developers, we have raised this issue and are seeking a discussion regarding module development within ABACUS.

Currently, ABACUS's various modules have provided our users and developers with a range of powerful features. However, technology and user requirements are constantly evolving, and we believe maybe it's time to examine and rethink our modules to ensure they meet future needs.

The purpose of this Issue is to invite developers and contributors to engage in discussions and plan the refactoring and development direction of our modules.

Describe the solution you'd like

Possible Discussion Topics:
We propose discussing the following topics in this Issue, but feel free to bring up related issues:

1. Current State of Modules: Please share your views and user experiences regarding the current modules.
2. Potential Module Improvements: Which modules do you think need improvement or redesign, and why?
3. Suggested New Features: Do you have any ideas for new features or modules? Please share your suggestions.
4. Performance Optimization: Any suggestions or optimization ideas related to module performance.
5. API Design: Any suggestions for API design for new modules or features?

How to Participate:
Please share your thoughts, suggestions, and discussions in this Issue. We encourage all developers and users to actively participate, whether it's technical suggestions or user experience feedback.

Additional Context

No response

Task list for Issue attackers

• Review and understand the proposed feature and its importance.
• Research on the existing solutions and relevant research articles/resources.
• Discuss with the team to evaluate the feasibility of implementing the feature.
• Create a design document outlining the proposed solution and implementation details.
• Get feedback from the team on the design document.
• Develop the feature following the agreed design.
• Write unit tests and integration tests for the feature.
• Update the documentation to include the new feature.
• Perform code review and address any issues.
• Merge the feature into the main branch.
• Monitor for any issues or bugs reported by users after the feature is released.
• Address any issues or bugs reported by users and continuously improve the feature.

[kirk0830]

This discussion is partially based on use and potential use of std::function in recent PR reviews:
#2998 #2876 #3065
, the std::function provides new possibility of decoupling between modules and "pythonicalization".

[hongriTianqi]

@denghuilu Would it be better to transfer this issue to discussion? After we have clear conclusions, we may create a series of issues with ToDos.

[kirk0830]

@denghuilu Would it be better to transfer this issue to discussion? After we have clear conclusions, we may create a series of issues with ToDos.

I think some developers will share their near future plan of refactor on codes, including single-compilation of HSolver module, deprecation of Psi class, "singletonization" of CG optimizer and so on. This issue can temporarily be left here, waiting for other developers noticing. A online discussion would be needed soon.
But the refactor plan can/should be published somewhere at least among all developers I think.