def setter_postconditions(
self, message: Message, field: Field, field_type: Type
) -> Sequence[Expr]:
return [
*[
Call("Invalid", [Name("Ctx"), Name(p.affixed_name)])
for p in message.successors(field)
if p != FINAL
],
*self.common.valid_path_to_next_field_condition(message, field, field_type),
*[
Equal(e, Old(e))
for e in [
Selected("Ctx", "Buffer_First"),
Selected("Ctx", "Buffer_Last"),
Selected("Ctx", "First"),
Call("Predecessor", [Name("Ctx"), Name(field.affixed_name)]),
Call("Valid_Next", [Name("Ctx"), Name(field.affixed_name)]),
]
+ [
Call(f"Get_{p.name}", [Name("Ctx")])
for p in message.definite_predecessors(field)
if isinstance(message.types[p], Scalar)
]
],
]
def context_cursor_unchanged(
message: model.Message, field: model.Field, predecessors: bool
) -> List[Expr]:
lower: model.Field
upper: model.Field
if predecessors:
if len(message.predecessors(field)) == 0:
return []
lower = message.fields[0]
upper = message.fields[message.fields.index(field) - 1]
else:
if len(message.successors(field)) == 0:
return []
lower = message.fields[message.fields.index(field) + 1]
upper = message.fields[-1]
return [
ForAllIn(
"F",
ValueRange(
lower=Variable(lower.affixed_name),
upper=Variable(upper.affixed_name),
type_identifier=ID("Field"),
),
Equal(
Call(
"Context_Cursors_Index",
[
Call(
"Context_Cursors",
[Variable("Ctx")],
),
Variable("F"),
],
),
Call(
"Context_Cursors_Index",
[
Old(
Call(
"Context_Cursors",
[Variable("Ctx")],
)
),
Variable("F"),
],
),
),
)
]