I notice that Thrift IDL has no user-defined parameter validating mechanism
at present, which is a common need for web services. As for Protobuf, the
parameter validation gets community support like PGV (protoc-gen-validate
<https://github.com/envoyproxy/protoc-gen-validate>), benefiting from its
strong plugin mechanism. If we can use build tools to generate codes for
simple and unchangeable constraints, the web service will be more robust
and developers will benefit from lighter work. Take a long-term view,
auto-generated parameter validation may be a step towards code-less web
services.
Here I propose the *Validation Annotation* for meeting this need. Hope to
get your reply as soon as possible！
