predicates

Classes

GripperOccupancy	Base class for predicates that check the gripper occupancy.
GripperIsFree	Checks if the gripper is holding something.
GripperIsNotFree	Checks if the gripper is free at the moment, so it can be used to grab something.

Module Contents

class predicates.GripperOccupancy

Base class for predicates that check the gripper occupancy.

end_effector: semantic_digital_twin.robots.robot_parts.EndEffector

Semantic annotation for the gripper that should be evaluated.

check_man_occupancy(condition: Callable[List[semantic_digital_twin.world_description.world_entity.Body], bool]) → bool

Checks the occupancy of the gripper against a condition.

The condition get the list of bodies that are under the TCP in the kinematic structure and returns a boolean.

Parameters:

condition – The condition that should be evaluated.

Returns:

True if the condition is satisfied, False otherwise.

class predicates.GripperIsFree

Bases: GripperOccupancy, krrood.entity_query_language.predicate.Predicate

Checks if the gripper is holding something.

Checks this by looking at the kinematic structure of the end_effector.

__call__() → bool

Evaluate the predicate for the supplied values.

classmethod _verbalization_fragment_(fields)

Structured verbalization for this predicate — a required clause (no string fallback).

Build the clause from the typed part-of-speech vocabulary (clause() with Noun / Verb / Copula / Prepositions / Adjective), composing the already-rendered field fragments in fields (keyed by field name). State only the affirmative, present-tense form: a Verb is given as its lemma, and the realisation passes inflect it (“work” → “works”) and agree its number. Returning a typed clause rather than a string keeps the predicate composable — a wrapping Not negates it automatically (a verb with do-support, “does not love”; a copula with suppletion, “is not reachable”) and coreference still reduces the operands.

..note:: Abstract, so every concrete predicate must supply a clause; a missing implementation

fails at (concrete) instantiation rather than only when the predicate is verbalized.

Example:

@dataclass(eq=False)
class Loves(Predicate):
    person_1: Person
    person_2: Person

    @classmethod
    def _verbalization_fragment_(cls, fields):
        return clause(Noun(fields["person_1"]), Verb("love"), Noun(fields["person_2"]))

Parameters:

fields – The rendered fragment for each predicate field, keyed by field name.

Returns:

The predicate’s verbalization fragment.

class predicates.GripperIsNotFree

Bases: GripperOccupancy, krrood.entity_query_language.predicate.Predicate

Checks if the gripper is free at the moment, so it can be used to grab something.

This is checked by looking at the kinematic structure.

__call__() → bool

Evaluate the predicate for the supplied values.

classmethod _verbalization_fragment_(fields)

Structured verbalization for this predicate — a required clause (no string fallback).

Build the clause from the typed part-of-speech vocabulary (clause() with Noun / Verb / Copula / Prepositions / Adjective), composing the already-rendered field fragments in fields (keyed by field name). State only the affirmative, present-tense form: a Verb is given as its lemma, and the realisation passes inflect it (“work” → “works”) and agree its number. Returning a typed clause rather than a string keeps the predicate composable — a wrapping Not negates it automatically (a verb with do-support, “does not love”; a copula with suppletion, “is not reachable”) and coreference still reduces the operands.

..note:: Abstract, so every concrete predicate must supply a clause; a missing implementation

fails at (concrete) instantiation rather than only when the predicate is verbalized.

Example:

@dataclass(eq=False)
class Loves(Predicate):
    person_1: Person
    person_2: Person

    @classmethod
    def _verbalization_fragment_(cls, fields):
        return clause(Noun(fields["person_1"]), Verb("love"), Noun(fields["person_2"]))

Parameters:

fields – The rendered fragment for each predicate field, keyed by field name.

Returns:

The predicate’s verbalization fragment.