private IEnumerable <ProgramState> TrySetObjectConstraint(ObjectConstraint constraint,
SymbolicValueConstraints oldConstraints, ProgramState programState)
{
if (oldConstraints.HasConstraint <BoolConstraint>())
{
if (constraint == ObjectConstraint.Null)
{
return(Enumerable.Empty <ProgramState>());
}
return(new[] { programState });
}
var oldObjectConstraint = oldConstraints.GetConstraintOrDefault <ObjectConstraint>();
if (oldObjectConstraint != null)
{
if (oldObjectConstraint != constraint)
{
return(Enumerable.Empty <ProgramState>());
}
return(new[] { programState.SetConstraint(this, constraint) });
}
throw new NotSupportedException($"Neither {nameof(BoolConstraint)}, nor {nameof(ObjectConstraint)}");
}
private IEnumerable <ProgramState> TrySetBoolConstraint(BoolConstraint constraint,
SymbolicValueConstraints oldConstraints, ProgramState programState)
{
if (oldConstraints.HasConstraint(ObjectConstraint.Null))
{
// It was null, and now it should be true or false
return(Enumerable.Empty <ProgramState>());
}
var oldBoolConstraint = oldConstraints.GetConstraintOrDefault <BoolConstraint>();
if (oldBoolConstraint != null &&
oldBoolConstraint != constraint)
{
return(Enumerable.Empty <ProgramState>());
}
// Either same bool constraint, or previously not null, and now a bool constraint
return(new[] { programState.SetConstraint(this, constraint) });
}