Initial common method

ifgen/common/python.py

@@ -5,13 +5,26 @@
 
 # internal
 from ifgen.generation.interface import GenerateTask
+from ifgen.generation.python import python_function, python_imports
 
 
 def create_python_common(task: GenerateTask) -> None:
     """Create a Python module that aggregates runtime registration tasks."""
 
     with task.boilerplate() as writer:
-        # Add registration function for all generated enumerations. Some base
-        # class for structs that registers the generated enumerations?
-        writer.empty()
-        writer.write("# todo")
+        # Write imports.
+        python_imports(
+            writer, third_party={"runtimepy.enum.registry": ["EnumRegistry"]}
+        )
+
+        with python_function(
+            writer,
+            "register_enums",
+            "Register generated enumerations.",
+            params="registry: EnumRegistry",
+        ):
+            writer.write("# iterate over all custom enums, register each")
+            writer.empty()
+            writer.write("del registry")
+
+        writer.write("# base class for structs that auto registers enums?")

ifgen/enum/python/__init__.py

@@ -18,14 +18,11 @@ def python_enum_header(task: GenerateTask, writer: IndentedFileWriter) -> None:
         writer, third_party={"runtimepy.enum.registry": ["RuntimeIntEnum"]}
     )
 
-    writer.empty()
-    writer.empty()
-
     with python_class(
         writer,
         task.name,
         task.resolve_description() or "No description.",
         parents=["RuntimeIntEnum"],
+        final_empty=0,
     ):
-        # Add members.
-        writer.write("# todo")
+        writer.write("# register members")

ifgen/generation/python/__init__.py

@@ -26,20 +26,25 @@ def write_imports(
 
 
 def python_imports(
-    writer: IndentedFileWriter, third_party: PythonImports = None
+    writer: IndentedFileWriter,
+    third_party: PythonImports = None,
+    final_empty: int = 2,
 ) -> None:
     """Write Python-module imports."""
 
     if third_party:
         write_imports(writer, "third-party", third_party)
 
+    writer.empty(count=final_empty)
+
 
 @contextmanager
 def python_class(
     writer: IndentedFileWriter,
     name: str,
     docstring: str,
     parents: list[str] = None,
+    final_empty: int = 2,
 ) -> Iterator[None]:
     """Write class definition contents."""
 
@@ -53,3 +58,26 @@ def python_class(
         writer.write(f'"""{docstring}"""')
         writer.empty()
         yield
+
+    writer.empty(count=final_empty)
+
+
+@contextmanager
+def python_function(
+    writer: IndentedFileWriter,
+    name: str,
+    docstring: str,
+    params: str = "",
+    return_type: str = "None",
+    final_empty: int = 2,
+) -> Iterator[None]:
+    """Write a Python function."""
+
+    writer.write(f"def {name}({params}) -> {return_type}:")
+
+    with writer.indented():
+        writer.write(f'"""{docstring}"""')
+        writer.empty()
+        yield
+
+    writer.empty(count=final_empty)