Resolve "Replacing Operations in SFG"

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:

test/test_signal_flow_graph.py

@@ -147,3 +147,61 @@ class TestComponents:
         mac_sfg = SFG(inputs = [inp1, inp2], outputs = [out1], name = "mac_sfg")
 
         assert set([comp.name for comp in mac_sfg.components]) == {"INP1", "INP2", "INP3", "ADD1", "ADD2", "MUL1", "OUT1", "S1", "S2", "S3", "S4", "S5", "S6", "S7"}
+
+
+class TestReplaceComponents:
+
+    def test_replace_addition_by_id(self, operation_tree):
+        sfg = SFG(outputs=[Output(operation_tree)])
+        component_id = "add1"
+
+        sfg = sfg.replace_component(Multiplication(name="Multi"), _id=component_id)
+        assert component_id not in sfg._components_by_id.keys()
+        assert "Multi" in sfg._components_by_name.keys()
+
+    def test_replace_addition_by_component(self, operation_tree):
+        sfg = SFG(outputs=[Output(operation_tree)])
+        component_id = "add1"
+        component = sfg.find_by_id(component_id)
+
+        sfg = sfg.replace_component(Multiplication(name="Multi"), _component=component)
+        assert component_id not in sfg._components_by_id.keys()
+        assert "Multi" in sfg._components_by_name.keys()
+
+    def test_replace_addition_large_tree(self, large_operation_tree):
+        sfg = SFG(outputs=[Output(large_operation_tree)])
+        component_id = "add3"
+
+        sfg = sfg.replace_component(Multiplication(name="Multi"), _id=component_id)
+        assert "Multi" in sfg._components_by_name.keys()
+        assert component_id not in sfg._components_by_id.keys()
+    
+    def test_replace_no_input_component(self, operation_tree):
+        sfg = SFG(outputs=[Output(operation_tree)])
+        component_id = "c1"
+        _const = sfg.find_by_id(component_id)
+        
+        sfg = sfg.replace_component(Constant(1), _id=component_id)
+        assert _const is not sfg.find_by_id(component_id)
+
+    def test_no_match_on_replace(self, large_operation_tree):
+        sfg = SFG(outputs=[Output(large_operation_tree)])
+        component_id = "addd1"
+
+        try:
+            sfg = sfg.replace_component(Multiplication(name="Multi"), _id=component_id)
+        except AssertionError:
+            assert True
+        else:
+            assert False
+
+    def test_not_equal_input(self, large_operation_tree):
+        sfg = SFG(outputs=[Output(large_operation_tree)])
+        component_id = "c1"
+
+        try:
+            sfg = sfg.replace_component(Multiplication(name="Multi"), _id=component_id)
+        except AssertionError:
+            assert True
+        else:
+            assert False