refactor: minimize ilpy

motile/constraints/constraint.py

@@ -3,19 +3,17 @@
 from abc import ABC, abstractmethod
 from typing import TYPE_CHECKING, Iterable
 
-if TYPE_CHECKING:
-    import ilpy
+from motile.expressions import Expression
 
+if TYPE_CHECKING:
     from motile.solver import Solver
 
 
 class Constraint(ABC):
     """A base class for a constraint that can be added to a solver."""
 
     @abstractmethod
-    def instantiate(
-        self, solver: Solver
-    ) -> Iterable[ilpy.Constraint | ilpy.Expression]:
+    def instantiate(self, solver: Solver) -> Iterable[Expression]:
         """Create and return specific linear constraints for the given solver.
 
         Args:

motile/constraints/expression.py

@@ -4,9 +4,9 @@
 import contextlib
 from typing import TYPE_CHECKING, Union
 
-import ilpy
+from motile.expressions import Expression, Constant
 
-from ..variables import EdgeSelected, NodeSelected, Variable
+from ..variables import EdgeSelected, NodeSelected, Variables
 from .constraint import Constraint
 
 if TYPE_CHECKING:
@@ -76,13 +76,13 @@ def __init__(
         self.eval_nodes = eval_nodes
         self.eval_edges = eval_edges
 
-    def instantiate(self, solver: Solver) -> list[ilpy.Constraint]:
+    def instantiate(self, solver: Solver) -> list[Expression]:
         # create two constraints: one to select nodes/edges, and one to exclude
-        select = ilpy.Constraint()
-        exclude = ilpy.Constraint()
+        select: Expression = Constant(0)
+        exclude: Expression = Constant(0)
         n_selected = 0  # number of nodes/edges selected
 
-        to_evaluate: list[tuple[NodesOrEdges, type[Variable]]] = []
+        to_evaluate: list[tuple[NodesOrEdges, type[Variables]]] = []
         if self.eval_nodes:
             to_evaluate.append((solver.graph.nodes, NodeSelected))
         if self.eval_edges:
@@ -99,17 +99,14 @@ def instantiate(self, solver: Solver) -> list[ilpy.Constraint]:
                     # contextlib.suppress (above) will just skip it and move on...
                     if eval(self._expression, None, node_or_edge):
                         # if the expression evaluates to True, we select the node/edge
-                        select.set_coefficient(indicator_variables[id_], 1)
+                        select += indicator_variables[id_]
                         n_selected += 1
                     else:
                         # Otherwise, we exclude it.
-                        exclude.set_coefficient(indicator_variables[id_], 1)
+                        exclude += indicator_variables[id_]
 
         # finally, apply the relation and value to the constraints
-        select.set_relation(ilpy.Relation.Equal)
-        select.set_value(n_selected)
-
-        exclude.set_relation(ilpy.Relation.Equal)
-        exclude.set_value(0)
+        select = select == n_selected
+        exclude = exclude == 0
 
         return [select, exclude]

motile/constraints/max_children.py

@@ -2,7 +2,7 @@
 
 from typing import TYPE_CHECKING, Iterable
 
-from ilpy.expressions import Constant, Expression
+from motile.expressions import Constant, Expression
 
 from ..variables import EdgeSelected
 from .constraint import Constraint

motile/constraints/max_parents.py

@@ -2,7 +2,7 @@
 
 from typing import TYPE_CHECKING, Iterable
 
-from ilpy.expressions import Constant, Expression
+from motile.expressions import Constant, Expression
 
 from ..variables import EdgeSelected
 from .constraint import Constraint

motile/costs/features.py

@@ -1,11 +1,8 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
-
 import numpy as np
 
-if TYPE_CHECKING:
-    import ilpy
+from motile.expressions import Variable
 
 
 class Features:
@@ -53,7 +50,7 @@ def _increase_features(self, num_features: int) -> None:
         self._values = np.hstack((self._values, new_features))
 
     def add_feature(
-        self, variable_index: int | ilpy.Variable, feature_index: int, value: float
+        self, variable_index: int | Variable, feature_index: int, value: float
     ) -> None:
         """Add a value to a feature.