Use np.ndarray for constraint methods in Instance

miplearn/instance/base.py

@@ -9,6 +9,7 @@ from typing import Any, List, TYPE_CHECKING, Dict
 import numpy as np
 
 from miplearn.features.sample import Sample, MemorySample
+from miplearn.types import ConstraintName, ConstraintCategory
 
 logger = logging.getLogger(__name__)
 
@@ -97,26 +98,23 @@ class Instance(ABC):
         """
         return names
 
-    def get_constraint_features(self) -> Dict[str, List[float]]:
-        return {}
+    def get_constraint_features(self, names: np.ndarray) -> np.ndarray:
+        return np.zeros((len(names), 1))
 
-    def get_constraint_categories(self) -> Dict[str, str]:
-        return {}
-
-    def has_static_lazy_constraints(self) -> bool:
-        return False
+    def get_constraint_categories(self, names: np.ndarray) -> np.ndarray:
+        return names
 
     def has_dynamic_lazy_constraints(self) -> bool:
         return False
 
-    def is_constraint_lazy(self, cid: str) -> bool:
-        return False
+    def are_constraints_lazy(self, names: np.ndarray) -> np.ndarray:
+        return np.zeros(len(names), dtype=bool)
 
     def find_violated_lazy_constraints(
         self,
         solver: "InternalSolver",
         model: Any,
-    ) -> List[str]:
+    ) -> List[ConstraintName]:
         """
         Returns lazy constraint violations found for the current solution.
 
@@ -142,7 +140,7 @@ class Instance(ABC):
         self,
         solver: "InternalSolver",
         model: Any,
-        violation: str,
+        violation: ConstraintName,
     ) -> None:
         """
         Adds constraints to the model to ensure that the given violation is fixed.
@@ -168,14 +166,14 @@ class Instance(ABC):
     def has_user_cuts(self) -> bool:
         return False
 
-    def find_violated_user_cuts(self, model: Any) -> List[str]:
+    def find_violated_user_cuts(self, model: Any) -> List[ConstraintName]:
         return []
 
     def enforce_user_cut(
         self,
         solver: "InternalSolver",
         model: Any,
-        violation: str,
+        violation: ConstraintName,
     ) -> Any:
         return None