Python messages.MessageBuilder类代码示例

def analyze_class_attribute_access(itype: Instance,
                                   name: str,
                                   context: Context,
                                   is_lvalue: bool,
                                   builtin_type: Callable[[str], Instance],
                                   msg: MessageBuilder) -> Type:
    node = itype.type.get(name)
    if not node:
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    if itype.type.is_enum and not (is_lvalue or is_decorated or is_method):
        return itype

    t = node.type
    if t:
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype.type, is_classmethod, builtin_type)

    if isinstance(node.node, TypeInfo):
        return type_object_type(cast(TypeInfo, node.node), builtin_type)

    return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))

def check_self_arg(functype: FunctionLike,
                   dispatched_arg_type: Type,
                   is_classmethod: bool,
                   context: Context, name: str,
                   msg: MessageBuilder) -> None:
    """For x.f where A.f: A1 -> T, check that meet(type(x), A) <: A1 for each overload.

    dispatched_arg_type is meet(B, A) in the following example

        def g(x: B): x.f
        class A:
            f: Callable[[A1], None]
    """
    # TODO: this is too strict. We can return filtered overloads for matching definitions
    for item in functype.items():
        if not item.arg_types or item.arg_kinds[0] not in (ARG_POS, ARG_STAR):
            # No positional first (self) argument (*args is okay).
            msg.no_formal_self(name, item, context)
        else:
            selfarg = item.arg_types[0]
            if is_classmethod:
                dispatched_arg_type = TypeType.make_normalized(dispatched_arg_type)
            if not subtypes.is_subtype(dispatched_arg_type, erase_to_bound(selfarg)):
                msg.incompatible_self_argument(name, dispatched_arg_type, item,
                                               is_classmethod, context)

def analyse_class_attribute_access(itype: Instance, name: str,
                                   context: Context, is_lvalue: bool,
                                   msg: MessageBuilder) -> Type:
    node = itype.type.get(name)
    if not node:
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    t = node.type
    if t:
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype.type, is_classmethod)

    if isinstance(node.node, TypeInfo):
        # TODO add second argument
        return type_object_type(cast(TypeInfo, node.node), None)

    return function_type(cast(FuncBase, node.node))

def check_for_explicit_any(typ: Optional[Type],
                           options: Options,
                           is_typeshed_stub: bool,
                           msg: MessageBuilder,
                           context: Context) -> None:
    if (options.disallow_any_explicit and
            not is_typeshed_stub and
            typ and
            has_explicit_any(typ)):
        msg.explicit_any(context)

def check_method_type(functype: FunctionLike, itype: Instance, context: Context, msg: MessageBuilder) -> None:
    for item in functype.items():
        if not item.arg_types or item.arg_kinds[0] != ARG_POS:
            # No positional first (self) argument.
            msg.invalid_method_type(item, context)
        else:
            # Check that self argument has type 'Any' or valid instance type.
            selfarg = item.arg_types[0]
            if not subtypes.is_equivalent(selfarg, itype):
                msg.invalid_method_type(item, context)

def apply_generic_arguments(callable: CallableType, types: List[Type],
                            msg: MessageBuilder, context: Context) -> Type:
    """Apply generic type arguments to a callable type.

    For example, applying [int] to 'def [T] (T) -> T' results in
    'def [-1:int] (int) -> int'. Here '[-1:int]' is an implicit bound type
    variable.

    Note that each type can be None; in this case, it will not be applied.
    """
    tvars = callable.variables
    if len(tvars) != len(types):
        msg.incompatible_type_application(len(tvars), len(types), context)
        return AnyType()

    # Check that inferred type variable values are compatible with allowed
    # values.  Also, promote subtype values to allowed values.
    types = types[:]
    for i, type in enumerate(types):
        values = callable.variables[i].values
        if values and type:
            if isinstance(type, AnyType):
                continue
            for value in values:
                if mypy.subtypes.is_subtype(type, value):
                    types[i] = value
                    break
            else:
                msg.incompatible_typevar_value(callable, i + 1, type, context)

    # Create a map from type variable id to target type.
    id_to_type = {}  # type: Dict[int, Type]
    for i, tv in enumerate(tvars):
        if types[i]:
            id_to_type[tv.id] = types[i]

    # Apply arguments to argument types.
    arg_types = [expand_type(at, id_to_type) for at in callable.arg_types]

    bound_vars = [(tv.id, id_to_type[tv.id])
                  for tv in tvars
                  if tv.id in id_to_type]

    # The callable may retain some type vars if only some were applied.
    remaining_tvars = [tv for tv in tvars if tv.id not in id_to_type]

    return CallableType(arg_types,
                    callable.arg_kinds,
                    callable.arg_names,
                    expand_type(callable.ret_type, id_to_type),
                    callable.fallback,
                    callable.name,
                    remaining_tvars,
                    callable.bound_vars + bound_vars,
                    callable.line, callable.repr)

def handle_partial_attribute_type(typ: PartialType, is_lvalue: bool, msg: MessageBuilder, context: Context) -> Type:
    if typ.type is None:
        # 'None' partial type. It has a well-defined type -- 'None'.
        # In an lvalue context we want to preserver the knowledge of
        # it being a partial type.
        if not is_lvalue:
            return NoneTyp()
        return typ
    else:
        msg.fail(messages.NEED_ANNOTATION_FOR_VAR, context)
        return AnyType()

def apply_generic_arguments(callable: CallableType, orig_types: Sequence[Optional[Type]],
                            msg: MessageBuilder, context: Context) -> CallableType:
    """Apply generic type arguments to a callable type.

    For example, applying [int] to 'def [T] (T) -> T' results in
    'def (int) -> int'.

    Note that each type can be None; in this case, it will not be applied.
    """
    tvars = callable.variables
    assert len(tvars) == len(orig_types)
    # Check that inferred type variable values are compatible with allowed
    # values and bounds.  Also, promote subtype values to allowed values.
    types = list(orig_types)
    for i, type in enumerate(types):
        assert not isinstance(type, PartialType), "Internal error: must never apply partial type"
        values = callable.variables[i].values
        if values and type:
            if isinstance(type, AnyType):
                continue
            if isinstance(type, TypeVarType) and type.values:
                # Allow substituting T1 for T if every allowed value of T1
                # is also a legal value of T.
                if all(any(is_same_type(v, v1) for v in values)
                       for v1 in type.values):
                    continue
            for value in values:
                if mypy.subtypes.is_subtype(type, value):
                    types[i] = value
                    break
            else:
                msg.incompatible_typevar_value(callable, type, callable.variables[i].name, context)
        upper_bound = callable.variables[i].upper_bound
        if type and not mypy.subtypes.is_subtype(type, upper_bound):
            msg.incompatible_typevar_value(callable, type, callable.variables[i].name, context)

    # Create a map from type variable id to target type.
    id_to_type = {}  # type: Dict[TypeVarId, Type]
    for i, tv in enumerate(tvars):
        typ = types[i]
        if typ:
            id_to_type[tv.id] = typ

    # Apply arguments to argument types.
    arg_types = [expand_type(at, id_to_type) for at in callable.arg_types]

    # The callable may retain some type vars if only some were applied.
    remaining_tvars = [tv for tv in tvars if tv.id not in id_to_type]

    return callable.copy_modified(
        arg_types=arg_types,
        ret_type=expand_type(callable.ret_type, id_to_type),
        variables=remaining_tvars,
    )

def analyse_member_var_access(name: str, itype: Instance, info: TypeInfo,
                              node: Context, is_lvalue: bool, is_super: bool,
                              msg: MessageBuilder,
                              report_type: Type = None) -> Type:
    """Analyse attribute access that does not target a method.

    This is logically part of analyse_member_access and the arguments are
    similar.
    """
    # It was not a method. Try looking up a variable.
    v = lookup_member_var_or_accessor(info, name, is_lvalue)

    vv = v
    if isinstance(vv, Decorator):
        # The associated Var node of a decorator contains the type.
        v = vv.var

    if isinstance(v, Var):
        # Found a member variable.
        var = v
        itype = map_instance_to_supertype(itype, var.info)
        if var.type:
            t = expand_type_by_instance(var.type, itype)
            if var.is_initialized_in_class and isinstance(t, FunctionLike):
                if is_lvalue:
                    if var.is_property:
                        msg.read_only_property(name, info, node)
                    else:
                        msg.cant_assign_to_method(node)

                if not var.is_staticmethod:
                    # Class-level function objects and classmethods become bound
                    # methods: the former to the instance, the latter to the
                    # class.
                    functype = cast(FunctionLike, t)
                    check_method_type(functype, itype, node, msg)
                    signature = method_type(functype)
                    if var.is_property:
                        # A property cannot have an overloaded type => the cast
                        # is fine.
                        return cast(Callable, signature).ret_type
                    else:
                        return signature
            return t
        else:
            if not var.is_ready:
                msg.cannot_determine_type(var.name(), node)
            # Implicit 'Any' type.
            return AnyType()
    elif isinstance(v, FuncDef):
        assert False, "Did not expect a function"

    # Could not find the member.
    if is_super:
        msg.undefined_in_superclass(name, node)
        return AnyType()
    else:
        return msg.has_no_attr(report_type or itype, name, node)

def handle_partial_attribute_type(typ: PartialType, is_lvalue: bool, msg: MessageBuilder,
                                  node: SymbolNode) -> Type:
    if typ.type is None:
        # 'None' partial type. It has a well-defined type -- 'None'.
        # In an lvalue context we want to preserver the knowledge of
        # it being a partial type.
        if not is_lvalue:
            return NoneTyp()
        return typ
    else:
        msg.need_annotation_for_var(node, node)
        return AnyType(TypeOfAny.from_error)

def analyze_member_var_access(name: str, itype: Instance, info: TypeInfo,
                              node: Context, is_lvalue: bool, is_super: bool,
                              builtin_type: Callable[[str], Instance],
                              not_ready_callback: Callable[[str, Context], None],
                              msg: MessageBuilder,
                              original_type: Type,
                              chk: 'mypy.checker.TypeChecker' = None) -> Type:
    """Analyse attribute access that does not target a method.

    This is logically part of analyze_member_access and the arguments are similar.

    original_type is the type of E in the expression E.var
    """
    # It was not a method. Try looking up a variable.
    v = lookup_member_var_or_accessor(info, name, is_lvalue)

    vv = v
    if isinstance(vv, Decorator):
        # The associated Var node of a decorator contains the type.
        v = vv.var

    if isinstance(v, Var):
        return analyze_var(name, v, itype, info, node, is_lvalue, msg,
                           original_type, not_ready_callback)
    elif isinstance(v, FuncDef):
        assert False, "Did not expect a function"
    elif not v and name not in ['__getattr__', '__setattr__', '__getattribute__']:
        if not is_lvalue:
            for method_name in ('__getattribute__', '__getattr__'):
                method = info.get_method(method_name)
                # __getattribute__ is defined on builtins.object and returns Any, so without
                # the guard this search will always find object.__getattribute__ and conclude
                # that the attribute exists
                if method and method.info.fullname() != 'builtins.object':
                    function = function_type(method, builtin_type('builtins.function'))
                    bound_method = bind_self(function, original_type)
                    typ = map_instance_to_supertype(itype, method.info)
                    getattr_type = expand_type_by_instance(bound_method, typ)
                    if isinstance(getattr_type, CallableType):
                        return getattr_type.ret_type

    if itype.type.fallback_to_any:
        return AnyType()

    # Could not find the member.
    if is_super:
        msg.undefined_in_superclass(name, node)
        return AnyType()
    else:
        if chk and chk.should_suppress_optional_error([itype]):
            return AnyType()
        return msg.has_no_attr(original_type, name, node)

def analyze_class_attribute_access(itype: Instance,
                                   name: str,
                                   context: Context,
                                   is_lvalue: bool,
                                   builtin_type: Callable[[str], Instance],
                                   not_ready_callback: Callable[[str, Context], None],
                                   msg: MessageBuilder,
                                   original_type: Type) -> Type:
    """original_type is the type of E in the expression E.var"""
    node = itype.type.get(name)
    if not node:
        if itype.type.fallback_to_any:
            return AnyType()
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    if itype.type.is_enum and not (is_lvalue or is_decorated or is_method):
        return itype

    t = node.type
    if t:
        if isinstance(t, PartialType):
            return handle_partial_attribute_type(t, is_lvalue, msg, node.node)
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype, is_classmethod, builtin_type, original_type)
    elif isinstance(node.node, Var):
        not_ready_callback(name, context)
        return AnyType()

    if isinstance(node.node, TypeVarExpr):
        return TypeVarType(node.tvar_def, node.tvar_def.line, node.tvar_def.column)

    if isinstance(node.node, TypeInfo):
        return type_object_type(node.node, builtin_type)

    if isinstance(node.node, MypyFile):
        # Reference to a module object.
        return builtin_type('builtins.module')

    if is_decorated:
        # TODO: Return type of decorated function. This is quick hack to work around #998.
        return AnyType()
    else:
        return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))

def analyze_member_var_access(
    name: str,
    itype: Instance,
    info: TypeInfo,
    node: Context,
    is_lvalue: bool,
    is_super: bool,
    builtin_type: Callable[[str], Instance],
    not_ready_callback: Callable[[str, Context], None],
    msg: MessageBuilder,
    report_type: Type = None,
    chk: "mypy.checker.TypeChecker" = None,
) -> Type:
    """Analyse attribute access that does not target a method.

    This is logically part of analyze_member_access and the arguments are
    similar.
    """
    # It was not a method. Try looking up a variable.
    v = lookup_member_var_or_accessor(info, name, is_lvalue)

    vv = v
    if isinstance(vv, Decorator):
        # The associated Var node of a decorator contains the type.
        v = vv.var
    if isinstance(v, Var):
        return analyze_var(name, v, itype, info, node, is_lvalue, msg, not_ready_callback)
    elif isinstance(v, FuncDef):
        assert False, "Did not expect a function"
    elif not v and name not in ["__getattr__", "__setattr__"]:
        if not is_lvalue:
            method = info.get_method("__getattr__")
            if method:
                typ = map_instance_to_supertype(itype, method.info)
                getattr_type = expand_type_by_instance(
                    method_type_with_fallback(method, builtin_type("builtins.function")), typ
                )
                if isinstance(getattr_type, CallableType):
                    return getattr_type.ret_type

    if itype.type.fallback_to_any:
        return AnyType()

    # Could not find the member.
    if is_super:
        msg.undefined_in_superclass(name, node)
        return AnyType()
    else:
        if chk and chk.should_suppress_optional_error([itype]):
            return AnyType()
        return msg.has_no_attr(report_type or itype, name, node)

def check_method_type(
    functype: FunctionLike, itype: Instance, is_classmethod: bool, context: Context, msg: MessageBuilder
) -> None:
    for item in functype.items():
        if not item.arg_types or item.arg_kinds[0] not in (ARG_POS, ARG_STAR):
            # No positional first (self) argument (*args is okay).
            msg.invalid_method_type(item, context)
        elif not is_classmethod:
            # Check that self argument has type 'Any' or valid instance type.
            selfarg = item.arg_types[0]
            # If this is a method of a tuple class, correct for the fact that
            # we passed to typ.fallback in analyze_member_access. See #1432.
            if isinstance(selfarg, TupleType):
                selfarg = selfarg.fallback
            if not subtypes.is_equivalent(selfarg, itype):
                msg.invalid_method_type(item, context)
        else:
            # Check that cls argument has type 'Any' or valid class type.
            # (This is sufficient for the current treatment of @classmethod,
            # but probably needs to be revisited when we implement Type[C]
            # or advanced variants of it like Type[<args>, C].)
            clsarg = item.arg_types[0]
            if isinstance(clsarg, CallableType) and clsarg.is_type_obj():
                if not subtypes.is_equivalent(clsarg.ret_type, itype):
                    msg.invalid_class_method_type(item, context)
            else:
                if not subtypes.is_equivalent(clsarg, AnyType()):
                    msg.invalid_class_method_type(item, context)

def analyze_class_attribute_access(itype: Instance,
                                   name: str,
                                   context: Context,
                                   is_lvalue: bool,
                                   builtin_type: Callable[[str], Instance],
                                   not_ready_callback: Callable[[str, Context], None],
                                   msg: MessageBuilder,
                                   original_type: Type) -> Optional[Type]:
    """original_type is the type of E in the expression E.var"""
    node = itype.type.get(name)
    if not node:
        if itype.type.fallback_to_any:
            return AnyType(TypeOfAny.special_form)
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    if itype.type.is_enum and not (is_lvalue or is_decorated or is_method):
        return itype

    t = node.type
    if t:
        if isinstance(t, PartialType):
            symnode = node.node
            assert symnode is not None
            return handle_partial_attribute_type(t, is_lvalue, msg, symnode)
        if not is_method and (isinstance(t, TypeVarType) or get_type_vars(t)):
            msg.fail(messages.GENERIC_INSTANCE_VAR_CLASS_ACCESS, context)
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype, is_classmethod, builtin_type, original_type)
    elif isinstance(node.node, Var):
        not_ready_callback(name, context)
        return AnyType(TypeOfAny.special_form)

    if isinstance(node.node, TypeVarExpr):
        msg.fail('Type variable "{}.{}" cannot be used as an expression'.format(
                 itype.type.name(), name), context)
        return AnyType(TypeOfAny.from_error)

    if isinstance(node.node, TypeInfo):
        return type_object_type(node.node, builtin_type)

    if isinstance(node.node, MypyFile):
        # Reference to a module object.
        return builtin_type('types.ModuleType')

    if is_decorated:
        # TODO: Return type of decorated function. This is quick hack to work around #998.
        return AnyType(TypeOfAny.special_form)
    else:
        return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))