feat: add internal class to manage and handle types

pddl/_validation.py

@@ -11,57 +11,14 @@
 #
 
 """This module defines validation functions for PDDL data structures."""
+from typing import Collection, Optional, Set, Tuple
 
-from typing import Collection, Dict, Optional, Set, Tuple
-
-from pddl.custom_types import name, to_names  # noqa: F401
+from pddl.custom_types import name, namelike, to_names  # noqa: F401
 from pddl.exceptions import PDDLValidationError
-from pddl.helpers.base import ensure_set, find_cycle
+from pddl.helpers.base import ensure_set
 from pddl.logic import Constant, Predicate
 from pddl.logic.terms import Term
-from pddl.parser.symbols import ALL_SYMBOLS, Symbols
-
-
-def _check_types_dictionary(type_dict: Dict[name, Optional[name]]) -> None:
-    """
-    Check the consistency of the types dictionary.
-
-    1) Empty types dictionary is correct by definition:
-    >>> _check_types_dictionary({})
-
-    2) The `object` type cannot be a subtype:
-    >>> a = name("a")
-    >>> _check_types_dictionary({name("object"): a})
-    Traceback (most recent call last):
-    ...
-    pddl.exceptions.PDDLValidationError: object must not have supertypes, but got 'object' is a subtype of 'a'
-
-    3) If cycles in the type hierarchy graph are present, an error is raised:
-    >>> a, b, c = to_names(["a", "b", "c"])
-    >>> _check_types_dictionary({a: b, b: c, c: a})
-    Traceback (most recent call last):
-    ...
-    pddl.exceptions.PDDLValidationError: cycle detected in the type hierarchy: a -> b -> c
-
-    :param type_dict: the types dictionary
-    """
-    if len(type_dict) == 0:
-        return
-
-    # check `object` type
-    object_name = name(Symbols.OBJECT.value)
-    if object_name in type_dict and type_dict[object_name] is not None:
-        object_supertype = type_dict[object_name]
-        raise PDDLValidationError(
-            f"object must not have supertypes, but got 'object' is a subtype of '{object_supertype}'"
-        )
-
-    # check cycles
-    cycle = find_cycle(type_dict)  # type: ignore
-    if cycle is not None:
-        raise PDDLValidationError(
-            "cycle detected in the type hierarchy: " + " -> ".join(cycle)
-        )
+from pddl.parser.symbols import ALL_SYMBOLS
 
 
 def _find_inconsistencies_in_typed_terms(

pddl/core.py

@@ -19,24 +19,23 @@
 from enum import Enum
 from typing import AbstractSet, Collection, Dict, Optional, Sequence, Set, cast
 
-from pddl._validation import (
-    _check_constant_types,
-    _check_types_dictionary,
-    _check_types_in_has_terms_objects,
-)
+from pddl._validation import _check_constant_types, _check_types_in_has_terms_objects
 from pddl.custom_types import name as name_type
-from pddl.custom_types import namelike, to_names_types
+from pddl.custom_types import namelike, to_names, to_names_types  # noqa: F401
+from pddl.exceptions import PDDLValidationError
 from pddl.helpers.base import (
     _typed_parameters,
     assert_,
     ensure,
     ensure_sequence,
     ensure_set,
+    find_cycle,
 )
 from pddl.logic.base import Formula, TrueFormula, is_literal
 from pddl.logic.predicates import DerivedPredicate, Predicate
 from pddl.logic.terms import Constant, Term, Variable
 from pddl.parser.symbols import RequirementSymbols as RS
+from pddl.parser.symbols import Symbols
 
 
 class Domain:
@@ -68,30 +67,19 @@ def __init__(
         """
         self._name = name_type(name)
         self._requirements = ensure_set(requirements)
-        self._types = to_names_types(ensure(types, dict()))
+        self._types = _Types(types, self._requirements)
         self._constants = ensure_set(constants)
         self._predicates = ensure_set(predicates)
         self._derived_predicates = ensure_set(derived_predicates)
         self._actions = ensure_set(actions)
 
-        self._all_types_set = self._get_all_types()
-
         self._check_consistency()
 
-    def _get_all_types(self) -> Set[name_type]:
-        """Get all types supported by this domain."""
-        if self._types is None:
-            return set()
-        result = set(self._types.keys()) | set(self._types.values())
-        result.discard(None)
-        return cast(Set[name_type], result)
-
     def _check_consistency(self) -> None:
         """Check consistency of a domain instance object."""
-        _check_types_dictionary(self._types)
-        _check_constant_types(self._constants, self._all_types_set)
-        _check_types_in_has_terms_objects(self._predicates, self._all_types_set)
-        _check_types_in_has_terms_objects(self._actions, self._all_types_set)  # type: ignore
+        _check_constant_types(self._constants, self._types.all_types)
+        _check_types_in_has_terms_objects(self._predicates, self._types.all_types)
+        _check_types_in_has_terms_objects(self._actions, self._types.all_types)  # type: ignore
         self._check_types_in_derived_predicates()
 
     def _check_types_in_derived_predicates(self) -> None:
@@ -101,7 +89,7 @@ def _check_types_in_derived_predicates(self) -> None:
             if self._derived_predicates
             else set()
         )
-        _check_types_in_has_terms_objects(dp_list, self._all_types_set)
+        _check_types_in_has_terms_objects(dp_list, self._types.all_types)
 
     @property
     def name(self) -> str:
@@ -136,7 +124,7 @@ def actions(self) -> AbstractSet["Action"]:
     @property
     def types(self) -> Dict[name_type, Optional[name_type]]:
         """Get the type definitions, if defined. Else, raise error."""
-        return self._types
+        return self._types.raw
 
     def __eq__(self, other):
         """Compare with another object."""
@@ -388,3 +376,98 @@ def __lt__(self, other):
             return self.value <= other.value
         else:
             return super().__lt__(other)
+
+
+class _Types:
+    """A class for representing and managing the types available in a PDDL Domain."""
+
+    def __init__(
+        self,
+        types: Optional[Dict[namelike, Optional[namelike]]] = None,
+        requirements: Optional[AbstractSet[Requirements]] = None,
+    ) -> None:
+        """Initialize the Types object."""
+        self._types = to_names_types(ensure(types, dict()))
+
+        self._all_types = self._get_all_types()
+        self._check_types_dictionary(self._types, ensure_set(requirements))
+
+    @property
+    def raw(self) -> Dict[name_type, Optional[name_type]]:
+        """Get the raw types dictionary."""
+        return self._types
+
+    @property
+    def all_types(self) -> Set[name_type]:
+        """Get all available types."""
+        return self._all_types
+
+    def _get_all_types(self) -> Set[name_type]:
+        """Get all types supported by the domain."""
+        if self._types is None:
+            return set()
+        result = set(self._types.keys()) | set(self._types.values())
+        result.discard(None)
+        return cast(Set[name_type], result)
+
+    @classmethod
+    def _check_types_dictionary(
+        cls,
+        type_dict: Dict[name_type, Optional[name_type]],
+        requirements: AbstractSet[Requirements],
+    ) -> None:
+        """
+        Check the consistency of the types dictionary.
+
+        1) Empty types dictionary is correct by definition:
+        >>> _Types._check_types_dictionary({}, set())
+
+        2) There are supertypes, but :typing requirement not specified
+        >>> a, b, c = to_names(["a", "b", "c"])
+        >>> _Types._check_types_dictionary({a: b, b: c}, set())
+        Traceback (most recent call last):
+        ...
+        pddl.exceptions.PDDLValidationError: typing requirement is not specified, but types are used: 'b', 'c'
+
+        3) The `object` type cannot be a subtype:
+        >>> a = name_type("a")
+        >>> _Types._check_types_dictionary({name_type("object"): a}, {Requirements.TYPING})
+        Traceback (most recent call last):
+        ...
+        pddl.exceptions.PDDLValidationError: object must not have supertypes, but got 'object' is a subtype of 'a'
+
+        4) If cycles in the type hierarchy graph are present, an error is raised:
+        >>> a, b, c = to_names(["a", "b", "c"])
+        >>> _Types._check_types_dictionary({a: b, b: c, c: a}, {Requirements.TYPING})
+        Traceback (most recent call last):
+        ...
+        pddl.exceptions.PDDLValidationError: cycle detected in the type hierarchy: a -> b -> c
+
+        :param type_dict: the types dictionary
+        """
+        if len(type_dict) == 0:
+            return
+
+        # check typing requirement
+        supertypes = {t for t in type_dict.values() if t is not None}
+        if len(supertypes) > 0 and Requirements.TYPING not in requirements:
+            raise PDDLValidationError(
+                "typing requirement is not specified, but types are used: '"
+                + "', '".join(map(str, sorted(supertypes)))
+                + "'"
+            )
+
+        # check `object` type
+        object_name = name_type(Symbols.OBJECT.value)
+        if object_name in type_dict and type_dict[object_name] is not None:
+            object_supertype = type_dict[object_name]
+            raise PDDLValidationError(
+                f"object must not have supertypes, but got 'object' is a subtype of '{object_supertype}'"
+            )
+
+        # check cycles
+        cycle = find_cycle(type_dict)  # type: ignore
+        if cycle is not None:
+            raise PDDLValidationError(
+                "cycle detected in the type hierarchy: " + " -> ".join(cycle)
+            )

tests/test_domain.py

@@ -17,7 +17,7 @@
 
 import pytest
 
-from pddl.core import Action, Domain
+from pddl.core import Action, Domain, Requirements
 from pddl.exceptions import PDDLValidationError
 from pddl.logic import Constant, Variable
 from pddl.logic.base import Not, TrueFormula
@@ -88,7 +88,11 @@ def test_cycles_in_type_defs_not_allowed() -> None:
     with pytest.raises(
         PDDLValidationError, match="cycle detected in the type hierarchy: A -> B -> C"
     ):
-        Domain("dummy", types={"A": "B", "B": "C", "C": "A"})
+        Domain(
+            "dummy",
+            requirements={Requirements.TYPING},
+            types={"A": "B", "B": "C", "C": "A"},
+        )
 
 
 def test_object_must_not_be_subtype() -> None:
@@ -100,7 +104,7 @@ def test_object_must_not_be_subtype() -> None:
         PDDLValidationError,
         match=rf"object must not have supertypes, but got 'object' is a subtype of '{my_type}'",
     ):
-        Domain("test", types=type_set)  # type: ignore
+        Domain("test", requirements={Requirements.TYPING}, types=type_set)  # type: ignore
 
 
 def test_constants_type_not_available() -> None: