zerodds-idl-lower

From the shape of an IDL file to the model.

Scopes and name binding, resolution, and the IDL rules the common AST cannot express structurally: the recursion OMG IDL 4.2 §7.4.1.4.4.4.4 does not admit, a declaration that reuses the name of its own scope (§7.5.2), the member-id rules, the annotations of DDS-XTypes 1.3 §7.3.1.2.

Where the products disagree, the answer is a named axis rather than a choice: KeyOnUnionDiscriminator, HashedIdCounter, HashedNameSpelling, NameOfTheEnclosingScope. Each has the clause's reading as its default and each vendor's measured reading as the other value, so --dialect rti and a build of the same file reach the same model by the same route.

This crate computes no layout. What the model means on the wire is zerodds-ast-layout's answer.