"""
Copyright 2017 Inmanta
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Contact: code@inmanta.com
"""
import copy
import functools
import numbers
from collections.abc import Sequence
from typing import Callable
from typing import List as PythonList
from typing import Optional
from inmanta.ast import DuplicateException, Locatable, LocatableString, Named, Namespace, NotFoundException, RuntimeException
from inmanta.execute.util import AnyType, NoneValue, Unknown
from inmanta.stable_api import stable_api
try:
from typing import TYPE_CHECKING
except ImportError:
TYPE_CHECKING = False
if TYPE_CHECKING:
from inmanta.ast.statements import ExpressionStatement
[docs]
@stable_api
class Type(Locatable):
"""
This class is the abstract base class for all types in the Inmanta :term:`DSL` that represent basic data. These are
types that are not relations. Instances of subclasses represent a type in the Inmanta language.
"""
[docs]
def validate(self, value: Optional[object]) -> bool:
"""
Validate the given value to check if it satisfies the constraints associated with this type. Returns true iff
validation succeeds, otherwise raises a :py:class:`inmanta.ast.RuntimeException`.
"""
return True
[docs]
def type_string(self) -> Optional[str]:
"""
Returns the type string as expressed in the Inmanta :term:`DSL`, if this type can be expressed in the :term:`DSL`.
Otherwise returns None.
"""
return None
def type_string_internal(self) -> str:
"""
Returns the internal string representation of the instance of the type. This is used by __str__
when type_string() returns None.
Use this method only when you explicitly need the internal string representation of the type.
"""
return "Type"
def __str__(self) -> str:
"""
Returns the string representation of the type, to be used for informative reporting as in error messages.
When a structured representation of the inmanta type is required, type_string() should be used instead.
"""
type_string: Optional[str] = self.type_string()
return type_string if type_string is not None else self.type_string_internal()
def normalize(self) -> None:
pass
[docs]
def is_primitive(self) -> bool:
"""
Returns true iff this type is a primitive type, i.e. number, string, bool.
"""
return False
[docs]
def get_base_type(self) -> "Type":
"""
Returns the base type for this type, i.e. the plain type without modifiers such as expressed by
`[]` and `?` in the :term:`DSL`.
"""
return self
[docs]
def with_base_type(self, base_type: "Type") -> "Type":
"""
Returns the type formed by replacing this type's base type with the supplied type.
"""
return base_type
class NamedType(Type, Named):
def get_double_defined_exception(self, other: "NamedType") -> "DuplicateException":
"""produce an error message for this type"""
raise DuplicateException(self, other, "Type %s is already defined" % (self.get_full_name()))
def type_string(self) -> str:
return self.get_full_name()
[docs]
@stable_api
class NullableType(Type):
"""
Represents a nullable type in the Inmanta :term:`DSL`. For example `NullableType(Number())` represents `number?`.
"""
def __init__(self, element_type: Type) -> None:
Type.__init__(self)
self.element_type: Type = element_type
def validate(self, value: Optional[object]) -> bool:
if isinstance(value, NoneValue):
return True
return self.element_type.validate(value)
def _wrap_type_string(self, string: str) -> str:
return "%s?" % string
def type_string(self) -> Optional[str]:
base_type_string: Optional[str] = self.element_type.type_string()
return None if base_type_string is None else self._wrap_type_string(base_type_string)
def type_string_internal(self) -> str:
return self._wrap_type_string(self.element_type.type_string_internal())
def normalize(self) -> None:
self.element_type.normalize()
def get_base_type(self) -> Type:
return self.element_type.get_base_type()
def with_base_type(self, base_type: Type) -> Type:
return NullableType(self.element_type.with_base_type(base_type))
def __eq__(self, other: object) -> bool:
if not isinstance(other, NullableType):
return NotImplemented
return self.element_type == other.element_type
[docs]
@stable_api
class Primitive(Type):
"""
Abstract base class representing primitive types.
"""
def __init__(self) -> None:
Type.__init__(self)
self.try_cast_functions: Sequence[Callable[[Optional[object]], object]] = []
[docs]
def cast(self, value: Optional[object]) -> object:
"""
Cast a value to this type. If the value can not be cast, raises a :py:class:`inmanta.ast.RuntimeException`.
"""
exception: RuntimeException = RuntimeException(None, f"Failed to cast '{value}' to {self}")
if isinstance(value, Unknown):
# propagate unknowns
return value
for cast in self.try_cast_functions:
try:
return cast(value)
except ValueError:
continue
except TypeError:
raise exception
raise exception
def type_string_internal(self) -> str:
return "Primitive"
def __eq__(self, other: object) -> bool:
if other.__class__ != self.__class__:
return NotImplemented
return True
[docs]
@stable_api
class Number(Primitive):
"""
This class represents an integer or a float in the configuration model.
"""
def __init__(self) -> None:
Primitive.__init__(self)
self.try_cast_functions: Sequence[Callable[[Optional[object]], numbers.Number]] = [float]
def cast(self, value: Optional[object]) -> object:
"""
Attempts to cast a given value to an int or a float.
"""
# Keep precision: cast to an int only if it already is an int
if isinstance(value, int):
return int(value)
return super().cast(value)
def validate(self, value: Optional[object]) -> bool:
"""
Validate the given value to check if it satisfies the constraints
associated with this type
"""
if isinstance(value, AnyType):
return True
if not isinstance(value, numbers.Number):
raise RuntimeException(None, f"Invalid value '{value}', expected {self.type_string()}")
return True # allow this function to be called from a lambda function
def is_primitive(self) -> bool:
return True
def get_location(self) -> None:
return None
def type_string(self) -> str:
return "number"
def type_string_internal(self) -> str:
return self.type_string()
@stable_api
class Float(Primitive):
"""
This class is an alias for the Number class and represents a float in
the configuration model.
"""
def __init__(self) -> None:
Primitive.__init__(self)
self.try_cast_functions: Sequence[Callable[[Optional[object]], object]] = [float]
def validate(self, value: Optional[object]) -> bool:
"""
Validate the given value to check if it satisfies the constraints
associated with this type
"""
if isinstance(value, AnyType):
return True
if not isinstance(value, float):
raise RuntimeException(None, f"Invalid value '{value}', expected {self.type_string()}")
return True # allow this function to be called from a lambda function
def is_primitive(self) -> bool:
return True
def get_location(self) -> None:
return None
def type_string(self) -> str:
return "float"
def type_string_internal(self) -> str:
return self.type_string()
[docs]
@stable_api
class Integer(Number):
"""
An instance of this class represents the int type in the configuration model.
"""
def __init__(self) -> None:
Number.__init__(self)
self.try_cast_functions: Sequence[Callable[[Optional[object]], object]] = [int]
def validate(self, value: Optional[object]) -> bool:
"""
Validate the given value to check if it satisfies the constraints
associated with this type
"""
if isinstance(value, AnyType):
return True
if not isinstance(value, numbers.Integral):
raise RuntimeException(None, f"Invalid value '{value}', expected {self.type_string()}")
return True # allow this function to be called from a lambda function
def type_string(self) -> str:
return "int"
[docs]
@stable_api
class Bool(Primitive):
"""
This class represents a simple boolean that can hold true or false.
"""
def __init__(self) -> None:
Primitive.__init__(self)
self.try_cast_functions: Sequence[Callable[[Optional[object]], object]] = [bool]
def validate(self, value: Optional[object]) -> bool:
"""
Validate the given value to check if it satisfies the constraints
associated with this type
"""
if isinstance(value, AnyType):
return True
if isinstance(value, bool):
return True
raise RuntimeException(None, f"Invalid value '{value}', expected {self.type_string()}")
def cast(self, value: Optional[object]) -> object:
return super().cast(value if not isinstance(value, NoneValue) else None)
def type_string(self) -> str:
return "bool"
def type_string_internal(self) -> str:
return self.type_string()
def is_primitive(self) -> bool:
return True
def get_location(self) -> None:
return None
[docs]
@stable_api
class String(Primitive):
"""
This class represents a string type in the configuration model.
"""
def __init__(self) -> None:
Primitive.__init__(self)
self.try_cast_functions: Sequence[Callable[[Optional[object]], object]] = [str]
def validate(self, value: Optional[object]) -> bool:
"""
Validate the given value to check if it satisfies the constraints
associated with this type
"""
if isinstance(value, AnyType):
return True
if not isinstance(value, str):
raise RuntimeException(None, f"Invalid value '{value}', expected {self.type_string()}")
return True
def cast(self, value: Optional[object]) -> object:
if value is True:
return "true"
if value is False:
return "false"
return super().cast(value)
def type_string(self) -> str:
return "string"
def type_string_internal(self) -> str:
return self.type_string()
def is_primitive(self) -> bool:
return True
def get_location(self) -> None:
return None
[docs]
@stable_api
class List(Type):
"""
Instances of this class represent a list type containing any types of values.
This class refers to the list type used in plugin annotations. For the list type in the Inmanta DSL, see `LiteralList`.
"""
def __init__(self):
Type.__init__(self)
def validate(self, value: Optional[object]) -> bool:
if value is None:
return True
if isinstance(value, AnyType):
return True
if not isinstance(value, list):
raise RuntimeException(None, f"Invalid value '{value}', expected {self.type_string()}")
return True
def type_string(self) -> str:
# This is not a type in the model, but it is used in plugin annotations, which are also part of the DSL.
return "list"
def type_string_internal(self) -> str:
return "List"
def get_location(self) -> None:
return None
[docs]
@stable_api
class TypedList(List):
"""
Instances of this class represent a list type containing any values of type element_type.
For example `TypedList(Number())` represents `number[]`.
"""
def __init__(self, element_type: Type) -> None:
List.__init__(self)
self.element_type: Type = element_type
def normalize(self) -> None:
self.element_type.normalize()
def validate(self, value: Optional[object]) -> bool:
if not List.validate(self, value):
return False
assert isinstance(value, list)
for element in value:
if not self.element_type.validate(element):
return False
return True
def _wrap_type_string(self, string: str) -> str:
return "%s[]" % string
def type_string(self) -> Optional[str]:
element_type_string = self.element_type.type_string()
return None if element_type_string is None else self._wrap_type_string(element_type_string)
def type_string_internal(self) -> str:
return self._wrap_type_string(self.element_type.type_string_internal())
def get_location(self) -> None:
return None
def get_base_type(self) -> Type:
return self.element_type
def with_base_type(self, base_type: Type) -> Type:
return TypedList(base_type)
def __eq__(self, other: object) -> bool:
if not isinstance(other, TypedList):
return NotImplemented
return self.element_type == other.element_type
[docs]
@stable_api
class LiteralList(TypedList):
"""
Instances of this class represent a list type containing only :py:class:`Literal` values.
This is the `list` type in the :term:`DSL`
"""
def __init__(self) -> None:
TypedList.__init__(self, Literal())
def type_string(self) -> str:
return "list"
def get_base_type(self) -> Type:
# The `list` type is not multi, thus it is the base type itself
return self
def with_base_type(self, base_type: Type) -> Type:
return self
def __eq__(self, other: object) -> bool:
if not isinstance(other, LiteralList):
return NotImplemented
return True
[docs]
@stable_api
class Dict(Type):
"""
Instances of this class represent a dict type with any types of values.
"""
def __init__(self) -> None:
Type.__init__(self)
def validate(self, value: Optional[object]) -> bool:
"""
Validate the given value to check if it satisfies the constraints
associated with this type
"""
if isinstance(value, AnyType):
return True
if value is None:
return True
if not isinstance(value, dict):
raise RuntimeException(None, f"Invalid value '{value}', expected {self.type_string()}")
return True
def type_string_internal(self) -> str:
return "Dict"
def type_string(self) -> str:
return "dict"
def get_location(self) -> None:
return None
[docs]
@stable_api
class TypedDict(Dict):
"""
Instances of this class represent a dict type containing only values of type element_type.
"""
def __init__(self, element_type: Type) -> None:
Dict.__init__(self)
self.element_type: Type = element_type
def normalize(self) -> None:
self.element_type.normalize()
def validate(self, value: Optional[object]) -> bool:
if not Dict.validate(self, value):
return False
assert isinstance(value, dict)
for element in value.values():
self.element_type.validate(element)
return True
def type_string_internal(self) -> str:
return "dict[%s]" % self.element_type.type_string_internal()
def get_location(self) -> None:
return None
[docs]
@stable_api
class LiteralDict(TypedDict):
"""
Instances of this class represent a dict type containing only :py:class:`Literal` values.
This is the `dict` type in the :term:`DSL`
"""
def __init__(self) -> None:
TypedDict.__init__(self, Literal())
def type_string(self) -> str:
return "dict"
def __eq__(self, other: object) -> bool:
if not isinstance(other, LiteralDict):
return NotImplemented
return True
[docs]
@stable_api
class Union(Type):
"""
Instances of this class represent a union of multiple types.
"""
def __init__(self, types: PythonList[Type]) -> None:
Type.__init__(self)
self.types: PythonList[Type] = types
def validate(self, value: object) -> bool:
for typ in self.types:
try:
if typ.validate(value):
return True
except RuntimeException:
pass
raise RuntimeException(None, f"Invalid value '{value}', expected {self}")
def type_string_internal(self) -> str:
return "Union[%s]" % ",".join(t.type_string_internal() for t in self.types)
[docs]
@stable_api
class Literal(Union):
"""
Instances of this class represent a literal in the configuration model. A literal is a primitive or a list or dict
where all values are literals themselves.
"""
def __init__(self) -> None:
Union.__init__(self, [NullableType(Float()), Number(), Bool(), String(), TypedList(self), TypedDict(self)])
def type_string_internal(self) -> str:
return "Literal"
[docs]
@stable_api
class ConstraintType(NamedType):
"""
A type that is based on a primitive type but defines additional constraints on this type.
These constraints only apply on the value of the type.
"""
def __init__(self, namespace: Namespace, name: str) -> None:
NamedType.__init__(self)
self.basetype: Optional[Type] = None # : ConstrainableType
self._constraint = None
self.name: str = name
self.namespace: Namespace = namespace
self.comment: Optional[str] = None
self.expression: Optional["ExpressionStatement"] = None
def normalize(self) -> None:
assert self.expression is not None
self.expression.normalize()
def set_constraint(self, expression) -> None:
"""
Set the constraint for this type. This baseclass for constraint
types requires the constraint to be set as a regex that can be
compiled.
"""
self.expression = expression
self._constraint = create_function(self, expression)
def get_constraint(self):
"""
Get the string representation of the constraint
"""
return self._constraint
constraint = property(get_constraint, set_constraint)
def validate(self, value: Optional[object]) -> bool:
"""
Validate the given value to check if it satisfies the constraint and
the basetype.
"""
if isinstance(value, AnyType):
return True
assert self.basetype is not None
self.basetype.validate(value)
assert self._constraint is not None
if not self._constraint(value):
raise RuntimeException(
self, f"Invalid value {repr(value)}, does not match constraint `{self.expression.pretty_print()}`"
)
return True
def type_string(self) -> str:
return f"{self.namespace}::{self.name}"
def type_string_internal(self) -> str:
return self.type_string()
def get_full_name(self) -> str:
return self.namespace.get_full_name() + "::" + self.name
def get_namespace(self) -> "Namespace":
return self.namespace
def get_double_defined_exception(self, other: "NamedType") -> DuplicateException:
return DuplicateException(self, other, "TypeConstraint %s is already defined" % (self.get_full_name()))
def create_function(tp: ConstraintType, expression: "ExpressionStatement"):
"""
Function that returns a function that evaluates the given expression.
The generated function accepts the unbound variables in the expression
as arguments.
"""
def function(*args, **kwargs):
"""
A function that evaluates the expression
"""
if len(args) != 1:
raise NotImplementedError()
try:
return expression.execute_direct({"self": args[0]})
except NotFoundException as e:
e.msg = "Unable to resolve `%s`: a type constraint can not reference variables." % e.stmt.name
raise e
return function
TYPES: dict[str, Type] = { # Part of the stable API
"string": String(),
"float": Float(),
"number": Number(),
"int": Integer(),
"bool": Bool(),
"list": LiteralList(),
"dict": LiteralDict(),
}
"""
Maps Inmanta :term:`DSL` types to their internal representation. For each key, value pair, `value.type_string()` is
guaranteed to return key.
"""
@stable_api
def resolve_type(locatable_type: LocatableString, resolver: Namespace) -> Type:
"""
Convert a locatable type string, into a real inmanta type, that can be used for validation.
:param locatable_type: An object pointing to the type expression.
:param resolver: The namespace that can be used to resolve the type expression
"""
# quickfix issue #1774
allowed_element_type: Type = Type()
if locatable_type.value == "list":
return List()
if locatable_type.value == "dict":
return TypedDict(allowed_element_type)
# stack of transformations to be applied to the base inmanta_type.Type
# transformations will be applied right to left
transformation_stack: List[Callable[[Type], Type]] = []
if locatable_type.value.endswith("?"):
# We don't want to modify the object we received as argument
locatable_type = copy.copy(locatable_type)
locatable_type.value = locatable_type.value[0:-1]
transformation_stack.append(NullableType)
if locatable_type.value.endswith("[]"):
# We don't want to modify the object we received as argument
locatable_type = copy.copy(locatable_type)
locatable_type.value = locatable_type.value[0:-2]
transformation_stack.append(TypedList)
return functools.reduce(
lambda acc, transform: transform(acc), reversed(transformation_stack), resolver.get_type(locatable_type)
)