Referential Integrity

Validating that id fields name an existing block with @ref.

§ 1Referential integrity with @ref

A field holding an identifier (or list<identifier>) that is semantically a reference to another block can declare that with @ref("kind"). wcl check then verifies every id names an existing block of that kind — anywhere in the document — and reports a dangling reference otherwise.

wcl

@block("screen") type Screen { @inline(0) id: identifier  name: utf8 }
@block("flow") type Flow {
  @inline(0) id: identifier
  @ref("screen") entry_screen: identifier   // must be a declared screen id
  @ref("screen") steps: list<identifier>    // every element checked
}