Add support for recursing Chains in ReactantCompatibleOptimisers

[ispielma]

The existing patches for Optimizers.jl directed ReactantOptimiser to Optimisers._adjust. This is a bug for Optimisers.OptimiserChain because Optimisers.adjust recurses through chains but Optimisers._adjust does not.

This pull request fixes this issue by adding ReactantOptimiser{<:Optimisers.OptimiserChain} methods to Optimisers.adjust.

[gemini-code-assist]

Summary of Changes

Hello @ispielma, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request resolves an issue where ReactantOptimiser instances containing an Optimisers.OptimiserChain were not having their internal optimizers correctly adjusted. By implementing specific Optimisers.adjust methods for these chained optimizers, the system now properly applies adjustments recursively, ensuring consistent behavior across all levels of nested optimizers.

Highlights

• Bug Fix: Addressed a bug where Optimisers._adjust did not correctly recurse through Optimisers.OptimiserChain instances when they were wrapped within a ReactantOptimiser, leading to improper adjustment of nested optimizers.
• New Optimisers.adjust Methods: Introduced two new methods for Optimisers.adjust specifically for ReactantOptimiser{<:Optimisers.OptimiserChain}. These methods ensure that adjustments (e.g., learning rate, keyword arguments) are applied recursively to all optimizers within the chain.
• Recursive Adjustment Logic: The new methods iterate through the opts field of the OptimiserChain and call Optimisers.adjust on each sub-optimizer, preserving the ReactantOptimiser wrapper around the adjusted chain.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request correctly addresses a bug where Optimisers.adjust would not recurse through an OptimiserChain wrapped in a ReactantOptimiser. The added methods for Optimisers.adjust now handle this case by iterating through the optimizers in the chain and applying the adjustment recursively. However, there is a small typo in one of the new function signatures that will cause a syntax error and needs to be fixed.

[ispielma]

/gemini review

[gemini-code-assist]

Code Review

This pull request correctly adds support for recursing through OptimiserChain for ReactantCompatibleOptimisers by implementing Optimisers.adjust, addressing the described bug. I've suggested a refactoring to combine the two new adjust methods into a single, more generic function to reduce code duplication and improve maintainability, which also offers a minor performance improvement.

[avik-pal]

will overloading _adjust work instead?

[ispielma]

It could be done that way, but there would be more duplicated code since the implementation would end up replicating the recursion code already present in Optimisers.adjust.