feat: support iguana::Algorithm::Run calls

Author: c-dilks

Clas12Banks/clas12reader.cpp

@@ -461,6 +461,8 @@ namespace clas12 {
       _event.getStructure(*ibank.get());
     }
 
+    // call user's custom read action
+    _readEventUserAction(this);
 
     return true;
   }

Clas12Banks/clas12reader.h

@@ -44,6 +44,7 @@
 #include <vector>
 #include <string>
 #include <iostream>
+#include <functional>
 
 #ifdef RCDB_MYSQL
    #include "rcdb_reader.h"
@@ -257,6 +258,13 @@ namespace clas12 {
       _verbose=level;
       _reader.setVerbose(level);
     }
+
+    // Set a "read action", a custom lambda function which is executed for every event within `readEvent()`.
+    // The lambda argument is a pointer to an instance of this `clas12reader` class
+    void SetReadAction(std::function<void(clas12reader*)> readEventUserAction) {
+      _readEventUserAction = readEventUserAction;
+    }
+
 
   protected:
 
@@ -345,7 +353,10 @@ namespace clas12 {
     bool _useFTBased{false};
     bool _isOpen{false};
     std::vector<std::string> _addBankNames;
-     
+
+    // user-definable lambda, called in `readEvent()`
+    std::function<void(clas12reader*)> _readEventUserAction = [](clas12reader* r) {};
+
     ///////////////////////////////DB
   private:
     int _runNo{0};

idea.cc

@@ -0,0 +1,17 @@
+// iguana user code
+clas12reader reader;
+iguana::algorithm algo;
+algo.Start();
+auto bank3 = algo.CreateBank("new::bank");
+auto read_action = [&algo, &bank3](clas12reader* CR) {
+  algo.Run(
+      *CR->bank1(),
+      *CR->bank2(),
+      bank3
+      );
+}
+reader.SetReadAction(read_action);
+
+// FIXME
+// FIXME: handle hipo::bank::rowlist iteration
+// FIXME