Eclipse Handly 0.8 Release Review

End Date of the Review Period: 

Reviews run for a minimum of one week. The outcome of the review is decided on this date. This is the last day to make comments or ask questions about this review.

Wednesday, December 6, 2017



Eclipse Handly 0.8 release attempts to finalize model-related parts of the Core API. To that end, it contains many API enhancements to elements, element deltas, the model, and working copy management. It also introduces new naming convention for model *Impl* interface methods and a separate package for model implementation support. Also, some optimizations have been made in skeletal implementations to allow Handly-based models scale even better than before.

New and Noteworthy
Migration Guide

Architectural Issues: 

There is no declared API in this release as both the API and the API policy may still evolve before the 1.0 release.

That being said, this release is focused on API quality and attempts to finalize the key parts of the Core API.

Due to the API rework involved, there are breaking changes that existing clients will need to accommodate to. We'll guide early adopters through the necessary migration steps.

Non-Code Aspects: 

We still have a PMI-based website [1], CBI-based build [2], an architectural overview [3], the contributor guide [4], committer FAQ [5], and a number of exemplary implementations including a basic Xtext-based example and a more advanced Java model example (Handly Examples).

All existing artifacts are kept up-to-date. The architectural overview reflects the still current (at the time of this writing) 0.7 version and will be updated once Handly 0.8 is released.

Also available is a step-by-step guide to getting started with Handly [6] (hosted on GitHub and made available under the EPL v1.0), which has enjoyed some encouraging feedback from early adopters. Based on the still current (at the time of this writing) 0.7 version, it will be updated to take advantage of Handly 0.8 immediately after the release.

We will also provide a migration guide for current adopters in the time leading to this release.


All discussion happens on open channels of developer mailing list [1], adopter forum [2] and bugzilla [3]. The project lead's blog posts on topics surrounding Handly [4] are syndicated to Planet Eclipse.

To provide existing adopters with an opportunity to give it an early try, leave feedback or raise concerns, a milestone build (corresponding to an attempt at API freeze towards this release) was made available [5].

Despite its incubation status, the project is known to be successfully used in two large-scale commercial products [6]. We have made available separately an experimental fork of Eclipse Java development tools based on Handly as a real-world example to encourage further adoption [7]. Broader community feedback and participation would be most welcome.