On 10/7/20 7:55 AM, Markus Armbruster wrote:
John Snow <js...@redhat.com> writes:
Annotations do not change runtime behavior.
This commit *only* adds annotations.
A note on typing of __init__: mypy requires init functions with no
parameters to document a return type of None to be considered fully
typed. In the case when there are input parameters, None may be omitted.
Since __init__ may never return any value, it is preferred to omit the
return annotation whenever possible.
Signed-off-by: John Snow <js...@redhat.com>
Reviewed-by: Eduardo Habkost <ehabk...@redhat.com>
Reviewed-by: Cleber Rosa <cr...@redhat.com>
Tested-by: Cleber Rosa <cr...@redhat.com>
---
scripts/qapi/mypy.ini | 5 -----
scripts/qapi/source.py | 31 ++++++++++++++++++-------------
2 files changed, 18 insertions(+), 18 deletions(-)
diff --git a/scripts/qapi/mypy.ini b/scripts/qapi/mypy.ini
index 8ab9ac52cc4..1b8555dfa39 100644
--- a/scripts/qapi/mypy.ini
+++ b/scripts/qapi/mypy.ini
@@ -34,11 +34,6 @@ disallow_untyped_defs = False
disallow_incomplete_defs = False
check_untyped_defs = False
-[mypy-qapi.source]
-disallow_untyped_defs = False
-disallow_incomplete_defs = False
-check_untyped_defs = False
-
[mypy-qapi.types]
disallow_untyped_defs = False
disallow_incomplete_defs = False
diff --git a/scripts/qapi/source.py b/scripts/qapi/source.py
index e97b9a8e15e..1cc6a5b82dc 100644
--- a/scripts/qapi/source.py
+++ b/scripts/qapi/source.py
@@ -11,37 +11,42 @@
import copy
import sys
+from typing import List, Optional, TypeVar
class QAPISchemaPragma:
- def __init__(self):
+ def __init__(self) -> None:
# Are documentation comments required?
self.doc_required = False
# Whitelist of commands allowed to return a non-dictionary
- self.returns_whitelist = []
+ self.returns_whitelist: List[str] = []
# Whitelist of entities allowed to violate case conventions
- self.name_case_whitelist = []
+ self.name_case_whitelist: List[str] = []
class QAPISourceInfo:
- def __init__(self, fname, line, parent):
+ T = TypeVar('T', bound='QAPISourceInfo')
+
+ def __init__(self: T, fname: str, line: int, parent: Optional[T]):
More ignorant questions (I'm abusing the review process to learn Python
type hints)...
Why do you need to annotate self here, but not elsewhere?
This is admittedly me being a little extra, but I thought it was a good
way to show a pattern for people who maybe hadn't been exposed to it yet.
This is a pattern that allows for subclassing. I am stating that this
__init__ method takes a parent of the same type as itself, whatever that
happens to actually be.
T is a TypeVar that we can use for Generics. By declaring the type of
self as that TypeVar, we bind T to self's type. When we annotate the
parent as a T, we are enforcing that the parent we receive is of the
same type as ourselves.
(Yep, we don't actually subclass QAPISourceInfo and I don't have plans
to. It felt slightly icky to hard-code the class type name, though. I
try to avoid that whenever I can. I'm not sure I would go so far as to
call it a code smell or an antipattern, but it's something I tend to
avoid anyway.)
Why do you use T instead of QAPISourceInfo?
self.fname = fname
self.line = line
self.parent = parent
- self.pragma = parent.pragma if parent else QAPISchemaPragma()
- self.defn_meta = None
- self.defn_name = None
+ self.pragma: QAPISchemaPragma = (
+ parent.pragma if parent else QAPISchemaPragma()
+ )
Type inference fail?
Yes:
qapi/source.py:34: error: Cannot determine type of 'pragma'
Found 1 error in 1 file (checked 14 source files)
+ self.defn_meta: Optional[str] = None
+ self.defn_name: Optional[str] = None
- def set_defn(self, meta, name):
+ def set_defn(self, meta: str, name: str) -> None:
self.defn_meta = meta
self.defn_name = name
- def next_line(self):
+ def next_line(self: T) -> T:
info = copy.copy(self)
info.line += 1
return info
- def loc(self):
+ def loc(self) -> str:
if self.fname is None:
return sys.argv[0]
ret = self.fname
@@ -49,13 +54,13 @@ def loc(self):
ret += ':%d' % self.line
return ret
- def in_defn(self):
+ def in_defn(self) -> str:
if self.defn_name:
return "%s: In %s '%s':\n" % (self.fname,
self.defn_meta, self.defn_name)
return ''
- def include_path(self):
+ def include_path(self) -> str:
ret = ''
parent = self.parent
while parent:
@@ -63,5 +68,5 @@ def include_path(self):
parent = parent.parent
return ret
- def __str__(self):
+ def __str__(self) -> str:
return self.include_path() + self.in_defn() + self.loc()