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)}");
}
internal override IEnumerable <ProgramState> SetConstraint(BoolConstraint boolConstraint,
SymbolicValueConstraints leftConstraints, SymbolicValueConstraints rightConstraints,
ProgramState programState)
{
if (boolConstraint == BoolConstraint.False)
{
return(RightOperand.TrySetConstraints(leftConstraints, programState)
.SelectMany(ps => LeftOperand.TrySetConstraints(rightConstraints, ps)));
}
return(RightOperand.TrySetOppositeConstraints(leftConstraints, programState)
.SelectMany(ps => LeftOperand.TrySetOppositeConstraints(rightConstraints, ps)));
}
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) });
}
private IEnumerable <ProgramState> TrySetConstraints(SymbolicValueConstraints constraints,
ProgramState programState, bool isOppositeConstraints)
{
IEnumerable <ProgramState> programStates = new [] { programState };
if (constraints == null)
{
return(programStates);
}
foreach (var constraint in constraints.GetConstraints())
{
programStates = programStates.SelectMany(ps =>
isOppositeConstraints
? TrySetOppositeConstraint(constraint, ps)
: TrySetConstraint(constraint, ps));
}
return(programStates);
}
internal abstract IEnumerable <ProgramState> SetConstraint(BoolConstraint boolConstraint,
SymbolicValueConstraints leftConstraints, SymbolicValueConstraints rightConstraints,
ProgramState programState);
public IEnumerable <ProgramState> TrySetOppositeConstraints(SymbolicValueConstraints constraints,
ProgramState programState)
{
return(TrySetConstraints(constraints, programState, true));
}
public bool TryGetConstraints(ProgramState programState, out SymbolicValueConstraints constraints)
{
return(programState.Constraints.TryGetValue(this, out constraints));
}
