Source: Model Driven Solutions ( Ed Willink)
The fourth QVT14-59 comment identifies that Primitive Domain root variables are not useable.
A top primitive domain input is only useful if the specification provides a mechanism to pass configuration to these inputs. It doesn't, so top primitive domains seem useless as is, and perhaps better supported by contextual properties.
In https://bugs.eclipse.org/bugs/show_bug.cgi?id=548536 I thought a non-top primitive domain might be useful, but realized that the primitives were inputs in one direction and outputs in another violating the 7.2.4 restriction to inputs. Now that multiple root variables are permitted it seems that the primitive domain root variables should be moved to the appropriate domain so that they are directional. RelToCore does not use primitive domains. It appears that a genuine use case for a primitive domain with a root variable is lacking.
Suggest: Replace the unfullied potential paramerization of top relations by immutable contextual trasformation properties in similar style to QVTo.
Primitive domains are then reduced to the vague host domain of shared relation variables such as "name : String".
Reported: QVT 1.3 — Sat, 22 Jun 2019 08:24 GMT
Updated: Sat, 22 Jun 2019 08:24 GMT