This is a very raw prototype of the interceptor API. This includes the interface definitions described in our proposal, and 3 implementations of a transformer to illustrate 3 of the syntax alternatives:
-
transformer.dart implements the default syntax using annotations. This transformation uses a normal Dart parser and can handle annotations on top-level properties and on fields.
-
with_syntax.dart implements the syntax of the form:
int x with interceptor = 1;. This implementation is more brittle, it simply uses regular expressions to do the substitutions. -
redirect_syntax.dart implements the syntax
int x >> interceptor = 1;. This implentation is also brittle (very similar to thewithsyntax).
Important Note: for simplicity, and since this prototype is just for
illustration purposes, these implementations don't use type resolution. The
default implementation blindly assumes that all annotations are interceptors.
All implementations assume that interceptors implement both ReadInterceptor
and WriteInterceptor. They support fields, getters, and setters, but there is
no support for methods at this time.
The test folder illustrates how these transformers work. All tests are written using field interceptors on classes, that way most of the code is in one shared location (common.dart) and the test for each syntax simply invokes the test function their own test object.