Resolve "Replacing Operations in SFG"

I added some thoughts on how this issue was implemented in #15 (closed), for most part on how we handle replacing several operations. Closes #15 (closed)

b_asic/signal_flow_graph.py

@@ -367,6 +367,44 @@ class SFG(AbstractOperation):
                             # Add connected operation to the queue of operations to visit.
                             op_stack.append(original_connected_op)
 
+    def replace_component(self, component: Operation, _component: Operation = None, _id: GraphID = None):
+        """Find and replace all components matching either on GraphID, Type or both.
+        Then return a new deepcopy of the sfg with the replaced component.
+
+        Arguments:
+        component: The new component(s), e.g Multiplication
+
+        Keyword arguments:
+        _component: The specific component to replace.
+        _id: The GraphID to match the component to replace.
+        """
+
+        assert _component is not None or _id is not None, \
+            "Define either operation to replace or GraphID of operation"
+
+        if _id is not None:
+            _component = self.find_by_id(_id)
+
+        assert _component is not None and isinstance(_component, Operation), \
+            "No operation matching the criteria found"
+        assert _component.output_count == component.output_count, \
+            "The output count may not differ between the operations"
+        assert _component.input_count == component.input_count, \
+            "The input count may not differ between the operations"
+
+        for index_in, _inp in enumerate(_component.inputs):
+            for _signal in _inp.signals:
+                _signal.remove_destination()
+                _signal.set_destination(component.input(index_in))
+        
+        for index_out, _out in enumerate(_component.outputs):
+            for _signal in _out.signals:
+                _signal.remove_source()
+                _signal.set_source(component.output(index_out))
+
+        # The old SFG will be deleted by Python GC
+        return self()
+
     def _evaluate_source(self, src: OutputPort, results: MutableResultMap, registers: MutableRegisterMap, prefix: str) -> Number:
         src_prefix = prefix
         if src_prefix: