| name | iets3-os-developer |
| description | Repo-specific development knowledge for IETS3/iets3.opensource — existing infrastructure and component knowledge across the variability languages, the KernelF expression languages, and physical units. TRIGGER when: implementing a ticket or bugfix, preparing or reviewing a PR, or doing any language development work in the iets3.opensource repository. |
What this skill is
The repo layer of the itemis MPS knowledge architecture for iets3.opensource ("os"). Load it together with the other two layers:
mps-developer (plugin mps-language-engineering) — generic MPS patterns; cross-references use its stable slugs (e.g. types.checking-rules).mps-platform-projects (plugin mps-itemis-ecosystem) — the IETS3 family layer: repo map, the core ↔ opensource split, and the shared ticket-to-merge workflow (branches, commits, CHANGELOG, PR structure, review etiquette, testing conventions).- This skill — what is genuinely specific to this repo: existing infrastructure and component knowledge, so you reach for existing mechanisms instead of inventing new ones.
Like the other layers, this is a growing knowledge base fed by analyzing merged PRs (maintainers use the mps-learn-from-pr skill of the mps-tooling-evolution plugin); it is deliberately incomplete. The sync marker above records when it was last reconciled against mps-developer's breaking-changes log.
Orientation
- Languages live under
code/languages/org.iets3.opensource/languages/ — one directory per language, models under models/; the MPS project is org.iets3.opensource.
- os is the upstream half of the IETS3 family: core consumes it as a pinned binary build. Changes here often get a companion PR in iets3.core — see "The core ↔ opensource split" in
mps-platform-projects.
- Branching, tickets, and the PR workflow follow the IETS3 family conventions — see
mps-platform-projects.
References (load progressively — only the topic(s) your task touches)
Organized by domain; this repo skill will grow, so knowledge is split by topic from the start:
references/variability.md — the variability languages (org.iets3.variability.*): feature-model checking rules and constraints, the skeleton-tree viewer.references/kernelf.md — the KernelF expression languages (org.iets3.core.expr.*, physical units excluded): number types and the typesystem.references/physunits.md — the physical-units language (typetags.physunits); note that typetags.units is the deprecated legacy implementation and must not be used.references/misc.md — cross-cutting knowledge not tied to one domain (e.g. sandbox/testing infrastructure); home for new topics until they warrant their own file.
