Redesign InternalSolver constraint methods

miplearn/components/dynamic_lazy.py

@@ -76,6 +76,7 @@ class DynamicLazyConstraintsComponent(Component):
         instance: Instance,
         model: Any,
     ) -> bool:
+        assert solver.internal_solver is not None
         logger.debug("Finding violated lazy constraints...")
         cids = instance.find_violated_lazy_constraints(solver.internal_solver, model)
         if len(cids) == 0:

miplearn/components/dynamic_user_cuts.py

@@ -53,8 +53,7 @@ class UserCutsComponent(Component):
         cids = self.dynamic.sample_predict(instance, training_data)
         logger.info("Enforcing %d user cuts ahead-of-time..." % len(cids))
         for cid in cids:
-            cobj = instance.build_user_cut(model, cid)
-            solver.internal_solver.add_constraint(cobj)
+            instance.enforce_user_cut(solver.internal_solver, model, cid)
         stats["UserCuts: Added ahead-of-time"] = len(cids)
 
     @overrides
@@ -73,9 +72,7 @@ class UserCutsComponent(Component):
             if cid in self.enforced:
                 continue
             assert isinstance(cid, Hashable)
-            cobj = instance.build_user_cut(model, cid)
-            assert cobj is not None
-            solver.internal_solver.add_cut(cobj)
+            instance.enforce_user_cut(solver.internal_solver, model, cid)
             self.enforced.add(cid)
             self.n_added_in_callback += 1
         if len(cids) > 0:

miplearn/components/static_lazy.py

@@ -12,7 +12,7 @@ from miplearn.classifiers import Classifier
 from miplearn.classifiers.counting import CountingClassifier
 from miplearn.classifiers.threshold import MinProbabilityThreshold, Threshold
 from miplearn.components.component import Component
-from miplearn.features import TrainingSample, Features
+from miplearn.features import TrainingSample, Features, Constraint
 from miplearn.types import LearningSolveStats
 
 logger = logging.getLogger(__name__)
@@ -44,7 +44,7 @@ class StaticLazyConstraintsComponent(Component):
         self.threshold_prototype: Threshold = threshold
         self.classifiers: Dict[Hashable, Classifier] = {}
         self.thresholds: Dict[Hashable, Threshold] = {}
-        self.pool: Dict[str, LazyConstraint] = {}
+        self.pool: Dict[str, Constraint] = {}
         self.violation_tolerance: float = violation_tolerance
         self.enforced_cids: Set[Hashable] = set()
         self.n_restored: int = 0
@@ -72,10 +72,8 @@ class StaticLazyConstraintsComponent(Component):
         self.pool = {}
         for (cid, cdict) in features.constraints.items():
             if cdict.lazy and cid not in self.enforced_cids:
-                self.pool[cid] = LazyConstraint(
-                    cid=cid,
-                    obj=solver.internal_solver.extract_constraint(cid),
-                )
+                self.pool[cid] = cdict
+                solver.internal_solver.remove_constraint(cid)
         logger.info(
             f"{len(self.enforced_cids)} lazy constraints kept; "
             f"{len(self.pool)} moved to the pool"
@@ -124,18 +122,18 @@ class StaticLazyConstraintsComponent(Component):
     def _check_and_add(self, solver: "LearningSolver") -> bool:
         assert solver.internal_solver is not None
         logger.info("Finding violated lazy constraints...")
-        enforced: List[LazyConstraint] = []
+        enforced: Dict[str, Constraint] = {}
         for (cid, c) in self.pool.items():
             if not solver.internal_solver.is_constraint_satisfied(
-                c.obj,
+                c,
                 tol=self.violation_tolerance,
             ):
-                enforced.append(c)
+                enforced[cid] = c
         logger.info(f"{len(enforced)} violations found")
-        for c in enforced:
-            del self.pool[c.cid]
-            solver.internal_solver.add_constraint(c.obj)
-            self.enforced_cids.add(c.cid)
+        for (cid, c) in enforced.items():
+            del self.pool[cid]
+            solver.internal_solver.add_constraint(c, name=cid)
+            self.enforced_cids.add(cid)
             self.n_restored += 1
         logger.info(
             f"{len(enforced)} constraints restored; {len(self.pool)} in the pool"