Merge pull request #3546 from jsiirola/feas-infeas

Map Constraint.Feasible/Infeasible to concrete constraints

Author: blnicho

pyomo/common/numeric_types.py

@@ -382,7 +382,8 @@ def value(obj, exception=True):
             tmp = obj(exception=True)
             if tmp is None:
                 raise ValueError(
-                    "No value for uninitialized NumericValue object %s" % (obj.name,)
+                    "No value for uninitialized %s object %s"
+                    % (type(obj).__name__, obj.name)
                 )
             return tmp
         except TemplateExpressionError:

pyomo/contrib/cp/transform/logical_to_disjunctive_walker.py

@@ -29,6 +29,10 @@
 from pyomo.gdp.disjunct import AutoLinkedBooleanVar, Disjunct, Disjunction
 
 
+def _dispatch_boolean_const(visitor, node):
+    return False, 1 if node.value else 0
+
+
 def _dispatch_boolean_var(visitor, node):
     if node not in visitor.boolean_to_binary_map:
         binary = node.get_associated_binary()
@@ -197,6 +201,7 @@ def _dispatch_atmost(visitor, node, *args):
 _operator_dispatcher[EXPR.AtMostExpression] = _dispatch_atmost
 
 _before_child_dispatcher = {}
+_before_child_dispatcher[EXPR.BooleanConstant] = _dispatch_boolean_const
 _before_child_dispatcher[BV.ScalarBooleanVar] = _dispatch_boolean_var
 _before_child_dispatcher[BV.BooleanVarData] = _dispatch_boolean_var
 _before_child_dispatcher[AutoLinkedBooleanVar] = _dispatch_boolean_var
@@ -264,5 +269,9 @@ def finalizeResult(self, result):
         # This LogicalExpression must evaluate to True (but note that we cannot
         # fix this variable to 1 since this logical expression could be living
         # on a Disjunct and later need to be relaxed.)
-        self.constraints.add(result >= 1)
+        expr = result >= 1
+        if expr.__class__ is bool:
+            self.constraints.add(Constraint.Feasible if expr else Constraint.Infeasible)
+        else:
+            self.constraints.add(expr)
         return result

pyomo/contrib/incidence_analysis/incidence.py

@@ -58,7 +58,7 @@ def _get_incident_via_standard_repn(
         except ValueError as err:
             # Catch error evaluating expression with uninitialized variables
             # TODO: Suppress logged error?
-            if "No value for uninitialized NumericValue" not in str(err):
+            if "No value for uninitialized VarData" not in str(err):
                 raise err
             value = None
         if value != 0:

pyomo/contrib/incidence_analysis/tests/test_incidence.py

@@ -33,7 +33,7 @@ def test_uninitialized_value_error_message(self):
         m = pyo.ConcreteModel()
         m.x = pyo.Var([1, 2])
         m.x[1].set_value(5)
-        msg = "No value for uninitialized NumericValue"
+        msg = "No value for uninitialized VarData"
         with self.assertRaisesRegex(ValueError, msg):
             pyo.value(1 + m.x[1] * m.x[2])
 

pyomo/core/base/constraint.py

@@ -39,6 +39,7 @@
     RangedExpression,
 )
 from pyomo.core.expr.expr_common import _type_check_exception_arg
+from pyomo.core.expr.relational_expr import TrivialRelationalExpression
 from pyomo.core.expr.template_expr import templatize_constraint
 from pyomo.core.base.component import ActiveComponentData, ModelComponentFactory
 from pyomo.core.base.global_set import UnindexedComponent_index
@@ -63,10 +64,11 @@
 
 _inf = float('inf')
 _nonfinite_values = {_inf, -_inf}
-_known_relational_expressions = {
+_known_relational_expression_types = {
     EqualityExpression,
     InequalityExpression,
     RangedExpression,
+    TrivialRelationalExpression,
 }
 _strict_relational_exprs = {True, (False, True), (True, False), (True, True)}
 _rule_returned_none_error = """Constraint '%s': rule returned None.
@@ -382,9 +384,7 @@ def get_value(self):
 
     def set_value(self, expr):
         """Set the expression on this constraint."""
-        # Clear any previously-cached normalized constraint
-        self._expr = None
-        if expr.__class__ in _known_relational_expressions:
+        if expr.__class__ in _known_relational_expression_types:
             if getattr(expr, 'strict', False) in _strict_relational_exprs:
                 raise ValueError(
                     "Constraint '%s' encountered a strict "
@@ -393,6 +393,7 @@ def set_value(self, expr):
                     "using '<=', '>=', or '=='." % (self.name,)
                 )
             self._expr = expr
+            return
 
         elif expr.__class__ is tuple:  # or expr_type is list:
             for arg in expr:
@@ -407,7 +408,7 @@ def set_value(self, expr):
                     "Constraint expressions expressed as tuples must "
                     "contain native numeric types or Pyomo NumericValue "
                     "objects. Tuple %s contained invalid type, %s"
-                    % (self.name, expr, arg.__class__.__name__)
+                    % (self.name, expr, type(arg).__name__)
                 )
             if len(expr) == 2:
                 #
@@ -420,6 +421,7 @@ def set_value(self, expr):
                         "cannot contain None [received %s]" % (self.name, expr)
                     )
                 self._expr = EqualityExpression(expr)
+                return
             elif len(expr) == 3:
                 #
                 # Form (ranged) inequality expression
@@ -430,6 +432,7 @@ def set_value(self, expr):
                     self._expr = InequalityExpression(expr[:2], False)
                 else:
                     self._expr = RangedExpression(expr, False)
+                return
             else:
                 raise ValueError(
                     "Constraint '%s' does not have a proper value. "
@@ -442,25 +445,9 @@ def set_value(self, expr):
         #
         # Ignore an 'empty' constraint
         #
-        elif expr.__class__ is type:
+        if expr is Constraint.Skip:
             del self.parent_component()[self.index()]
-            if expr is Constraint.Skip:
-                return
-            elif expr is Constraint.Infeasible:
-                # TODO: create a trivial infeasible constraint.  This
-                # could be useful in the case of GDP where certain
-                # disjuncts are trivially infeasible, but we would still
-                # like to express the disjunction.
-                # del self.parent_component()[self.index()]
-                raise ValueError("Constraint '%s' is always infeasible" % (self.name,))
-            else:
-                raise ValueError(
-                    "Constraint '%s' does not have a proper "
-                    "value. Found '%s'\nExpecting a tuple or "
-                    "relational expression. Examples:"
-                    "\n   sum(model.costs) == model.income"
-                    "\n   (0, model.price[item], 50)" % (self.name, str(expr))
-                )
+            return
 
         elif expr is None:
             raise ValueError(_rule_returned_none_error % (self.name,))
@@ -479,17 +466,18 @@ def set_value(self, expr):
             try:
                 if expr.is_expression_type(ExpressionType.RELATIONAL):
                     self._expr = expr
+                    return
             except AttributeError:
                 pass
-            if self._expr is None:
-                msg = (
-                    "Constraint '%s' does not have a proper "
-                    "value. Found '%s'\nExpecting a tuple or "
-                    "relational expression. Examples:"
-                    "\n   sum(model.costs) == model.income"
-                    "\n   (0, model.price[item], 50)" % (self.name, str(expr))
-                )
-                raise ValueError(msg)
+
+        raise ValueError(
+            "Constraint '%s' does not have a proper "
+            "value. Found %s '%s'\nExpecting a tuple or "
+            "relational expression. Examples:"
+            "\n   sum(model.costs) == model.income"
+            "\n   (0, model.price[item], 50)"
+            % (self.name, type(expr).__name__, str(expr))
+        )
 
     def lslack(self):
         """
@@ -619,10 +607,9 @@ class Constraint(ActiveIndexedComponent):
 
     _ComponentDataClass = ConstraintData
 
-    class Infeasible(object):
-        pass
+    Infeasible = TrivialRelationalExpression('Infeasible', (1, 0))
+    Feasible = TrivialRelationalExpression('Feasible', (0, 0))
 
-    Feasible = ActiveIndexedComponent.Skip
     NoConstraint = ActiveIndexedComponent.Skip
     Violated = Infeasible
     Satisfied = Feasible
@@ -640,11 +627,11 @@ def __new__(cls: Type[IndexedConstraint], *args, **kwds) -> IndexedConstraint: .
 
     def __new__(cls, *args, **kwds):
         if cls != Constraint:
-            return super(Constraint, cls).__new__(cls)
+            return super().__new__(cls)
         if not args or (args[0] is UnindexedComponent_set and len(args) == 1):
-            return super(Constraint, cls).__new__(AbstractScalarConstraint)
+            return super().__new__(AbstractScalarConstraint)
         else:
-            return super(Constraint, cls).__new__(IndexedConstraint)
+            return super().__new__(IndexedConstraint)
 
     @overload
     def __init__(self, *indexes, expr=None, rule=None, name=None, doc=None): ...
@@ -901,7 +888,7 @@ def set_value(self, expr):
         """Set the expression on this constraint."""
         if not self._data:
             self._data[None] = self
-        return super(ScalarConstraint, self).set_value(expr)
+        return super().set_value(expr)
 
     #
     # Leaving this method for backward compatibility reasons.
@@ -928,6 +915,7 @@ class SimpleConstraint(metaclass=RenamedClass):
         'add',
         'set_value',
         'to_bounded_expression',
+        'expr',
         'body',
         'lower',
         'upper',
@@ -981,7 +969,7 @@ def __init__(self, **kwargs):
         _rule = kwargs.pop('rule', None)
         self._starting_index = kwargs.pop('starting_index', 1)
 
-        super(ConstraintList, self).__init__(Set(dimen=1), **kwargs)
+        super().__init__(Set(dimen=1), **kwargs)
 
         self.rule = Initializer(
             _rule, treat_sequences_as_mappings=False, allow_generators=True