public override IEnumerable <ProgramState> TrySetConstraint(SymbolicValueConstraint constraint, ProgramState currentProgramState)
{
var boolConstraint = constraint as BoolConstraint;
if (boolConstraint == null)
{
return(new[] { currentProgramState });
}
SymbolicValueConstraint oldConstraint;
if (TryGetConstraint(currentProgramState, out oldConstraint) &&
oldConstraint is BoolConstraint /* could also be ObjectConstraint.NotNull, which can be overridden */ &&
oldConstraint != constraint)
{
return(Enumerable.Empty <ProgramState>());
}
SymbolicValueConstraint leftConstraint;
var leftHasConstraint = LeftOperand.TryGetConstraint(currentProgramState, out leftConstraint);
SymbolicValueConstraint rightConstraint;
var rightHasConstraint = RightOperand.TryGetConstraint(currentProgramState, out rightConstraint);
var relationship = GetRelationship(boolConstraint);
var newProgramState = currentProgramState.TrySetRelationship(relationship);
if (newProgramState == null)
{
return(Enumerable.Empty <ProgramState>());
}
if (!rightHasConstraint && !leftHasConstraint)
{
return(new[] { newProgramState });
}
return(SetConstraint(boolConstraint, leftConstraint, rightConstraint, newProgramState));
}
