defvisit_match_stmt(self,s:MatchStmt)->None:

named_subject:Expression

ifisinstance(s.subject,CallExpr):

id=s.subject.callee.fullnameifisinstance(s.subject.callee,RefExpr)else""

v=Var(name)

named_subject=NameExpr(name)

named_subject.node=v

else:

named_subject=s.subject

withself.binder.frame_context(can_skip=False,fall_through=0):

subject_type=get_proper_type(self.expr_checker.accept(s.subject))

forp,g,binzip(s.patterns,s.guards,s.bodies):

current_subject_type=self.expr_checker.narrow_type_from_binder(

s.subject,subject_type

named_subject,subject_type

)

pattern_type=self.pattern_checker.accept(p,current_subject_type)

withself.binder.frame_context(can_skip=True,fall_through=2):

else_map:TypeMap= {}

else:

pattern_map,else_map=conditional_types_to_typemaps(

s.subject,pattern_type.type,pattern_type.rest_type

named_subject,pattern_type.type,pattern_type.rest_type

)

self.remove_capture_conflicts(pattern_type.captures,inferred_types)

self.push_type_map(pattern_map)

andexpr.fullname==case_target.fullname

):

type_map[s.subject]=type_map[expr]

type_map[named_subject]=type_map[expr]

self.push_type_map(guard_map)

self.accept(b)

reveal_type(a) # N: Revealed type is "builtins.str"

[case testMatchCapturePatternFromFunctionReturningUnion]

def func1(arg: bool) -> str | int: ...

def func2(arg: bool) -> bytes | int: ...

def main() -> None:

match func1(True):

case str(a):

match func2(True):

case c:

reveal_type(a) # N: Revealed type is "builtins.str"

reveal_type(c) # N: Revealed type is "Union[builtins.bytes, builtins.int]"

reveal_type(a) # N: Revealed type is "builtins.str"

case a:

reveal_type(a) # N: Revealed type is "builtins.int"

-- Guards --

[case testMatchSimplePatternGuard]