Merge pull request #2353 from lf-lang/self-defined

Define self variable so it can be used in instantiations

core/src/main/java/org/lflang/generator/python/PythonReactorGenerator.java

@@ -133,12 +133,25 @@ public static String generatePythonClassInstantiations(
       // setting parameter values.
       code.pr("bank_index = " + PyUtil.bankIndexName(instance));
       code.pr(generatePythonClassInstantiation(instance, className));
-    }
 
-    for (ReactorInstance child : instance.children) {
-      code.pr(generatePythonClassInstantiations(child, main));
+      if (!instance.children.isEmpty()) {
+        // Define self so that instantiations of contained reactors can refer to parameters.
+        // First, save the previous definition of self to restore after instantiating children.
+        // But do not do this for the main reactor.
+        if (instance.getParent() != null) {
+          code.pr("previous_self = self");
+        }
+        code.pr("self = " + PyUtil.reactorRef(instance));
+
+        for (ReactorInstance child : instance.children) {
+          code.pr(generatePythonClassInstantiations(child, main));
+        }
+        if (instance.getParent() != null) {
+          code.pr("self = previous_self");
+        }
+      }
+      code.unindent();
     }
-    code.unindent();
     return code.toString();
   }
 

test/Python/src/BankIndex.lf

@@ -0,0 +1,14 @@
+target Python
+
+reactor A(bank_index=0, value=0) {
+  reaction(startup) {=
+    print("bank_index: {:d}, value: {:d}".format(self.bank_index, self.value))
+    if (self.value != 4 - self.bank_index):
+      sys.stderr.write("ERROR: Expected value to be 4 - bank_index.\n")
+      exit(1)
+  =}
+}
+
+main reactor(table = [4, 3, 2, 1]) {
+  a = new[4] A(value = {= self.table[bank_index] =})
+}