From: Marc-André Lureau <marcandre.lureau@redhat.com>

Introduce IfNot predicate class, for 'not' condition expressions.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 scripts/qapi/common.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
index 102d347348..6236bfc457 100644
--- a/scripts/qapi/common.py
+++ b/scripts/qapi/common.py
@@ -224,6 +224,28 @@ def __eq__(self, other: object) -> bool:
         return self.option == other.option
 
 
+class IfNot(IfPredicate):
+    def __init__(self, pred: IfPredicate):
+        self.pred = pred
+
+    def docgen(self) -> str:
+        return "not " + self.pred.docgen()
+
+    def cgen(self) -> str:
+        return "!" + self.pred.cgen()
+
+    def __bool__(self) -> bool:
+        return bool(self.pred)
+
+    def __repr__(self) -> str:
+        return f"IfNot({self.pred!r})"
+
+    def __eq__(self, other: object) -> bool:
+        if not isinstance(other, type(self)):
+            return False
+        return self.pred == other.pred
+
+
 class IfPredicateList(IfPredicate):
     C_SEP = ""
     DOC_SEP = ""
-- 
2.29.0

On 4/29/21 9:40 AM, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> Introduce IfNot predicate class, for 'not' condition expressions.
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>   scripts/qapi/common.py | 22 ++++++++++++++++++++++
>   1 file changed, 22 insertions(+)
> 
> diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
> index 102d347348..6236bfc457 100644
> --- a/scripts/qapi/common.py
> +++ b/scripts/qapi/common.py
> @@ -224,6 +224,28 @@ def __eq__(self, other: object) -> bool:
>           return self.option == other.option
>   
>   
> +class IfNot(IfPredicate):
> +    def __init__(self, pred: IfPredicate):
> +        self.pred = pred
> +
> +    def docgen(self) -> str:
> +        return "not " + self.pred.docgen()
> +
> +    def cgen(self) -> str:
> +        return "!" + self.pred.cgen()
> +
> +    def __bool__(self) -> bool:
> +        return bool(self.pred)
> +
> +    def __repr__(self) -> str:
> +        return f"IfNot({self.pred!r})"
> +
> +    def __eq__(self, other: object) -> bool:
> +        if not isinstance(other, type(self)):
> +            return False
> +        return self.pred == other.pred
> +
> +

Seems fine. Lot of boilerplate going on, but I don't have quick ideas 
for reducing it.

So far we have:

IfPredicate (abstract)

IfOption (wraps a <str>)
IfNot (wraps <IfPredicate>)
IfPredicateList (wraps <List[IfPredicate]>)
   - IfAll
   - IfAny

with fairly similar methods and boilerplate. I'm itching to reduce it a 
little, somehow...

--js

>   class IfPredicateList(IfPredicate):
>       C_SEP = ""
>       DOC_SEP = ""
> 

Tested-by: John Snow <jsnow@redhat.com>