@@ -25,7 +25,13 @@
from .parser import QAPISchemaParser
-class QAPISchemaEntity:
+class Visitable:
+ """Abstract duck that suggests a class is visitable."""
+ def visit(self, visitor: 'QAPISchemaVisitor') -> None:
+ raise NotImplementedError
+
+
+class QAPISchemaEntity(Visitable):
meta: Optional[str] = None
def __init__(self, name: str, info, doc, ifcond=None, features=None):
@@ -136,7 +142,7 @@ def visit_event(self, name, info, ifcond, features, arg_type, boxed):
pass
-class QAPISchemaModule:
+class QAPISchemaModule(Visitable):
def __init__(self, name):
self.name = name
self._entity_list = []
@@ -812,7 +818,7 @@ def visit(self, visitor):
self.arg_type, self.boxed)
-class QAPISchema:
+class QAPISchema(Visitable):
def __init__(self, fname):
self.fname = fname
parser = QAPISchemaParser(fname)
Python doesn't have anything quite exactly like Traits, Interfaces, or Mixins; but we can approximate it. Add a 'Visitable' class that enforces a type signature for the visit() method; this way, mypy is ensuring that even for otherwise unrelated classes that do not inherit from a common base, this signature will always be forced to be compatible. Signed-off-by: John Snow <jsnow@redhat.com> --- scripts/qapi/schema.py | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)