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

@@ -5,7 +5,7 @@ TODO: More info.
 
 from typing import NewType, List, Iterable, Sequence, Dict, Optional, DefaultDict, Set
 from numbers import Number
-from collections import defaultdict, deque
+from collections import defaultdict, deque, Iterable as CIterable
 
 from b_asic.port import SignalSourceProvider, OutputPort
 from b_asic.operation import Operation, AbstractOperation
@@ -350,6 +350,53 @@ class SFG(AbstractOperation):
             input_values.append(self._evaluate_source(input_src))
         return src.operation.evaluate_output(src.index, input_values)
 
+    def replace_component(self, _component: List[Operation], _id: List[GraphID] = None, _type: List[Operation] = 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 list of new component(s), e.g Multiplication
+    
+        Keyword arguments:
+        _id: The list of GraphID(s) to match the component to replace.
+        _type: The list of Type(s) to match the component to replace.
+        """
+
+        _id = [_id] if not isinstance(_id, CIterable) or isinstance(_id, str) else _id
+        _type = [_type] if not isinstance(_type, CIterable) else _type
+        _component = [_component] if not isinstance(_component, CIterable) else _component
+        components = set()
+
+        for comp_id in _id:
+            if comp_id is None:
+                continue
+
+            components |= {value for key, value in self._components_by_id.items() if key == comp_id}
+
+        for comp_type in _type:
+            if comp_type is None:
+                continue
+
+            components |= {comp for comp in self.components if isinstance(comp, comp_type)}
+        
+        assert sum([comp.output_count for comp in _component]) == sum([comp.output_count for comp in components])
+        assert sum([comp.input_count for comp in _component]) == sum([comp.input_count for comp in components])
+
+        for index, comp in enumerate(components):
+            component = _component if not isinstance(_component, CIterable) else _component[index]
+
+            for index_in, _inp in enumerate(comp.inputs):
+                for _signal in _inp.signals:
+                    _signal.remove_destination()
+                    _signal.set_destination(component.input(index_in))
+            
+            for index_out, _out in enumerate(comp.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.deep_copy()
     
     def __str__(self):
         """Prints operations, inputs and outputs in a SFG