"""
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 numbers
import typing
from typing import Callable
from typing import List as PythonList
from typing import Optional, Sequence
from inmanta.ast import (
DuplicateException,
Locatable,
Location,
Named,
Namespace,
NotFoundException,
RuntimeException,
TypeNotFoundException,
)
from inmanta.execute.util import AnyType, NoneValue
try:
from typing import TYPE_CHECKING
except ImportError:
TYPE_CHECKING = False
if TYPE_CHECKING:
from inmanta.ast.statements import ExpressionStatement
class BasicResolver(object):
def __init__(self, types):
self.types = types
def get_type(self, namespace, name):
if not isinstance(name, str):
raise Exception("Should Not Occur, bad AST construction")
if "::" in name:
if name in self.types:
return self.types[name]
else:
raise TypeNotFoundException(name, namespace)
elif name in TYPES:
return self.types[name]
else:
cns = namespace
while cns is not None:
full_name = "%s::%s" % (cns.get_full_name(), name)
if full_name in self.types:
return self.types[full_name]
cns = cns.get_parent()
raise TypeNotFoundException(name, namespace)
class NameSpacedResolver(object):
def __init__(self, ns):
self.ns = ns
def get_type(self, name):
return self.ns.get_type(name)
def get_resolver_for(self, namespace: Namespace):
return NameSpacedResolver(namespace)
[docs]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()))
[docs]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]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, "Failed to cast '%s' to %s" % (value, self))
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]class Number(Primitive):
"""
This class represents an integer or float in the configuration model. On
these numbers the following operations are supported:
+, -, /, *
"""
def __init__(self) -> None:
Primitive.__init__(self)
self.try_cast_functions: Sequence[Callable[[Optional[object]], numbers.Number]] = [int, 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, numbers.Number):
raise RuntimeException(None, "Invalid value '%s', expected Number" % value)
return True # allow this function to be called from a lambda function
def is_primitive(self) -> bool:
return True
def get_location(self) -> Location:
return None
def type_string(self) -> str:
return "number"
def type_string_internal(self) -> str:
return self.type_string()
[docs]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:
if not super().validate(value):
return False
if not isinstance(value, numbers.Integral):
raise RuntimeException(None, "Invalid value '%s', expected %s" % (value, self.type_string()))
return True
def type_string(self) -> str:
return "int"
[docs]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, "Invalid value '%s', expected Bool" % value)
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) -> Location:
return None
[docs]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, "Invalid value '%s', expected String" % value)
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) -> Location:
return None
[docs]class List(Type):
"""
Instances of this class represent a list type containing any types of values.
"""
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, "Invalid value '%s', expected %s" % (value, self.type_string()))
return True
def type_string_internal(self) -> str:
return "List"
def get_location(self) -> Location:
return None
[docs]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: Optional[str] = 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) -> Location:
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]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]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, "Invalid value '%s', expected dict" % value)
return True
def type_string_internal(self) -> str:
return "Dict"
def get_location(self) -> Location:
return None
[docs]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) -> Location:
return None
[docs]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]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, "Invalid value '%s', expected %s" % (value, self))
def type_string_internal(self) -> str:
return "Union[%s]" % ",".join((t.type_string_internal() for t in self.types))
[docs]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(Number()), Bool(), String(), TypedList(self), TypedDict(self)])
def type_string_internal(self) -> str:
return "Literal"
[docs]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, "Invalid value %s, does not match constraint `%s`" % (repr(value), self.expression.pretty_print())
)
return True
def type_string(self):
return "%s::%s" % (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: typing.Dict[str, Type] = {
"string": String(),
"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.
"""