Feature request: Friendly Error System for Processing

Relevant sub-area for this feature?

Other (specify if possible)

Feature details

Feature description

During Google Summer of Code 2023, a Friendly Error Messages system for Processing (inspired by the p5.js Friendly Error System) was developed by Will Rabalais (@WillRabalais04) with mentorship by Sam Pottinger (@sampottinger). This work adds clearer, contextual error messages, documentation links, and debugger improvements.

However, this work was never included in Processing and is not available to users today.

This request is to review, update if needed, and include this work in a future Processing release.

Note: This is meant to document work completed during GSoC 2023 and to put a pin in it for future consideration. It does not signal urgency, assign responsibility, or presume the level of effort required. The goal is mainly to ensure this work is visible and not lost.

Benefits

• Improves error messages that are currently cryptic and hard to understand
• Helps beginners debug and learn more effectively
• Brings Processing closer to p5.js in terms of learning-centered tooling

Challenges

• Updating the 2023 code to match the current Processing codebase and UI system (Compose)
• Expanding test coverage and checking language server compatibility

Additional context

• Original PR (legacy Processing4 repo)
• GSoC 2023 Wrap-up post
• Will's Project report
• p5.js FES Contributor Docs
• Friendly Errors i18n Book

Screenshots

Would you like to help implement this feature?

No, I’m just suggesting the feature

Start by reviewing the original PR 771 and the GSoC 2023 project report to understand the existing Friendly Error Messages implementation. Then compare it with the current Processing codebase and Compose UI, including its test and language-server needs. Done means an updated, reviewed system is integrated into a future Processing release with expanded coverage and compatible debugger behavior.