mypy.binder.ConditionalTypeBinder

class documentation

class ConditionalTypeBinder: (source)

Keep track of conditional types of variables.

NB: Variables are tracked by literal expression, so it is possible to confuse the binder; for example,

``` class A:

a = None # type: Union[int, str]

x = A() lst = [x] reveal_type(x.a) # Union[int, str] x.a = 1 reveal_type(x.a) # int reveal_type(lst[0].a) # Union[int, str] lst[0].a = 'a' reveal_type(x.a) # int reveal_type(lst[0].a) # str ```

Method	`__init__`	Undocumented
Method	`accumulate_type_assignments`	Push a new map to collect assigned types in multiassign from union.
Method	`allow_jump`	Undocumented
Method	`assign_type`	Undocumented
Method	`cleanse`	Remove all references to a Node from the binder.
Method	`frame_context`	Return a context manager that pushes/pops frames on enter/exit.
Method	`get`	Undocumented
Method	`handle_break`	Undocumented
Method	`handle_continue`	Undocumented
Method	`invalidate_dependencies`	Invalidate knowledge of types that include expr, but not expr itself.
Method	`is_unreachable`	Undocumented
Method	`is_unreachable_warning_suppressed`	Undocumented
Method	`most_recent_enclosing_type`	Undocumented
Method	`pop_frame`	Pop a frame and return it.
Method	`push_frame`	Push a new frame into the binder.
Method	`put`	Undocumented
Method	`suppress_unreachable_warnings`	Undocumented
Method	`top_frame_context`	A variant of frame_context for use at the top level of a namespace (module, function, or class).
Method	`unreachable`	Undocumented
Method	`update_from_options`	Update the frame to reflect that each key will be updated as in one of the frames. Return whether any item changes.
Instance Variable	`break_frames`	Undocumented
Instance Variable	`continue_frames`	Undocumented
Instance Variable	`declarations`	Undocumented
Instance Variable	`dependencies`	Undocumented
Instance Variable	`frames`	Undocumented
Instance Variable	`last_pop_changed`	Undocumented
Instance Variable	`next_id`	Undocumented
Instance Variable	`options_on_return`	Undocumented
Instance Variable	`try_frames`	Undocumented
Instance Variable	`type_assignments`	Undocumented
Method	`_add_dependencies`	Undocumented
Method	`_cleanse_key`	Remove all references to a key from the binder.
Method	`_get`	Undocumented
Method	`_get_id`	Undocumented
Method	`_put`	Undocumented

def __init__(self): (source)

Undocumented

@contextmanager
def accumulate_type_assignments(self): (source)

Push a new map to collect assigned types in multiassign from union.

If this map is not None, actual binding is deferred until all items in the union are processed (a union of collected items is later bound manually by the caller).

Returns
`Iterator[Assigns]`	Undocumented

def allow_jump(self, index): (source)

Undocumented

Parameters
index:`int`	Undocumented

def assign_type(self, expr, type, declared_type, restrict_any=False): (source)

Undocumented

Parameters
expr:`Expression`	Undocumented
type:`Type`	Undocumented
declared_type:`Optional[Type]`	Undocumented
restrict_any:`bool`	Undocumented

def cleanse(self, expr): (source)

Remove all references to a Node from the binder.

Parameters
expr:`Expression`	Undocumented

@contextmanager
def frame_context(self, *, can_skip, fall_through=1, break_frame=0, continue_frame=0, conditional_frame=False, try_frame=False): (source)

Return a context manager that pushes/pops frames on enter/exit.

If can_skip is True, control flow is allowed to bypass the newly-created frame.

If fall_through > 0, then it will allow control flow that falls off the end of the frame to escape to its ancestor fall_through levels higher. Otherwise control flow ends at the end of the frame.

If break_frame > 0, then 'break' statements within this frame will jump out to the frame break_frame levels higher than the frame created by this call to frame_context. Similarly for continue_frame and 'continue' statements.

If try_frame is true, then execution is allowed to jump at any point within the newly created frame (or its descendants) to its parent (i.e., to the frame that was on top before this call to frame_context).

After the context manager exits, self.last_pop_changed indicates whether any types changed in the newly-topmost frame as a result of popping this frame.

Parameters
can_skip:`bool`	Undocumented
fall_through:`int`	Undocumented
break_frame:`int`	Undocumented
continue_frame:`int`	Undocumented
conditional_frame:`bool`	Undocumented
try_frame:`bool`	Undocumented
Returns
`Iterator[Frame]`	Undocumented

def get(self, expr): (source)

Undocumented

Parameters
expr:`Expression`	Undocumented
Returns
`Optional[Type]`	Undocumented

def handle_break(self): (source)

Undocumented

def handle_continue(self): (source)

Undocumented

def invalidate_dependencies(self, expr): (source)

Invalidate knowledge of types that include expr, but not expr itself.

For example, when expr is foo.bar, invalidate foo.bar.baz.

It is overly conservative: it invalidates globally, including in code paths unreachable from here.

Parameters
expr:`BindableExpression`	Undocumented

def is_unreachable(self): (source)

Undocumented

Returns
`bool`	Undocumented

def is_unreachable_warning_suppressed(self): (source)

Undocumented

Returns
`bool`	Undocumented

def most_recent_enclosing_type(self, expr, type): (source)

Undocumented

Parameters
expr:`BindableExpression`	Undocumented
type:`Type`	Undocumented
Returns
`Optional[Type]`	Undocumented

def pop_frame(self, can_skip, fall_through): (source)

Pop a frame and return it.

See frame_context() for documentation of fall_through.

Parameters
can_skip:`bool`	Undocumented
fall_through:`int`	Undocumented
Returns
`Frame`	Undocumented

def push_frame(self, conditional_frame=False): (source)

Push a new frame into the binder.

Parameters
conditional_frame:`bool`	Undocumented
Returns
`Frame`	Undocumented

def put(self, expr, typ): (source)

Undocumented

Parameters
expr:`Expression`	Undocumented
typ:`Type`	Undocumented

def suppress_unreachable_warnings(self): (source)

Undocumented

@contextmanager
def top_frame_context(self): (source)

A variant of frame_context for use at the top level of a namespace (module, function, or class).

Returns
`Iterator[Frame]`	Undocumented

def unreachable(self): (source)

Undocumented

def update_from_options(self, frames): (source)

Update the frame to reflect that each key will be updated as in one of the frames. Return whether any item changes.

If a key is declared as AnyType, only update it if all the options are the same.

Parameters
frames:`List[Frame]`	Undocumented
Returns
`bool`	Undocumented

break_frames: List[int] = (source)

Undocumented

continue_frames: List[int] = (source)

Undocumented

declarations: Dict[Key, Optional[Type]] = (source)

Undocumented

dependencies: Dict[Key, Set[Key]] = (source)

Undocumented

frames = (source)

Undocumented

last_pop_changed = (source)

Undocumented

next_id: int = (source)

Undocumented

options_on_return: List[List[Frame]] = (source)

Undocumented

try_frames: Set[int] = (source)

Undocumented

type_assignments = (source)

Undocumented

def _add_dependencies(self, key, value=None): (source)

Undocumented

Parameters
key:`Key`	Undocumented
value:`Optional[Key]`	Undocumented

def _cleanse_key(self, key): (source)

Remove all references to a key from the binder.

Parameters
key:`Key`	Undocumented

def _get(self, key, index=-1): (source)

Undocumented

Parameters
key:`Key`	Undocumented
index:`int`	Undocumented
Returns
`Optional[Type]`	Undocumented

def _get_id(self): (source)

Undocumented

Returns
`int`	Undocumented

def _put(self, key, type, index=-1): (source)

Undocumented

Parameters
key:`Key`	Undocumented
type:`Type`	Undocumented
index:`int`	Undocumented