Changes between Version 143 and Version 144 of j2p

Timestamp:

10/10/24 12:18:39 (7 weeks ago)

Author:

wouter

Comment:

--

j2p

@@ -199 +199 @@
 {{{@NonNull}}} is NOT inherited by subclasses. Therefore {{{@NonNull}}} has to be repeated in the derived classes.
 }}}
+
+=== @Defer
+{{{@Defer}}} is a qualifier for Type specifications. The type that has this annotation is suggested to be imported later.  The translator will double quote such annotated types and suppress import of that class.
+
+For example, consider the cyclicref testcode in the core:
+{{{
+public class P {
+        private @Defer Q q = null;
+        public void join(@Defer Q q) {
+                this.q = q;
+        }
+}
+}}}
+
+The class Q that is referred from P refers back to Q. Without the @Defer annotations, class Q would have to be imported, resulting in a cyclic import. With the annotation however, the P class is translated as 
+{{{
+class P:
+ def join(self,q:"Optional[Q]") -> None:
+  self.__q=q
+ def __init__(self):
+  self.__q:"Optional[Q]" = None
+}}}
+
+This avoids the cyclic import, at the expense of some loss in python typing. Of course  the type checking is still done at the java side.