A constraint checker evaluates domain-specific language content or its abstract syntax tree (AST) against conditions. Each failed condition becomes an issue—an error or warning—with a message that helps domain experts repair the model before later failures occur. section 9.0
A practical checker follows this shape:
- Accept an AST object and compute every violation in its context. section 9.2.2
- Express each rule as a condition; when it fails, push a helpful issue message into an array. section 9.2.2
- Compute issues inside the reactive projection so feedback stays beside the affected domain element. section 9.2.2
Immediate attribute feedback
An attribute with an empty name receives a warning marker and exposes its issue message in a tooltip. A clickable message can supplement the tooltip where hover interaction is unsuitable.
