public override object VisitAssignmentExpression(AssignmentExpression assignment, object data)
{
base.VisitAssignmentExpression(assignment, data);
// Combine "x = x op y" into "x op= y"
BinaryOperatorExpression binary = assignment.Right as BinaryOperatorExpression;
if (binary != null && assignment.Operator == AssignmentOperatorType.Assign)
{
if (CanConvertToCompoundAssignment(assignment.Left) && assignment.Left.IsMatch(binary.Left))
{
assignment.Operator = GetAssignmentOperatorForBinaryOperator(binary.Operator);
if (assignment.Operator != AssignmentOperatorType.Assign)
{
// If we found a shorter operator, get rid of the BinaryOperatorExpression:
assignment.CopyAnnotationsFrom(binary);
assignment.Right = binary.Right.WithAnnotation(assignment.Right.GetAllRecursiveILRanges());
assignment.AddAnnotation(new RestoreOriginalAssignOperatorAnnotation(binary));
}
}
}
if (context.Settings.IntroduceIncrementAndDecrement && (assignment.Operator == AssignmentOperatorType.Add || assignment.Operator == AssignmentOperatorType.Subtract))
{
// detect increment/decrement
if (assignment.Right.IsMatch(new PrimitiveExpression(1)))
{
// only if it's not a custom operator
if (assignment.Annotation <IMethod>() == null)
{
UnaryOperatorType type;
// When the parent is an expression statement, pre- or post-increment doesn't matter;
// so we can pick post-increment which is more commonly used (for (int i = 0; i < x; i++))
if (assignment.Parent is ExpressionStatement)
{
type = (assignment.Operator == AssignmentOperatorType.Add) ? UnaryOperatorType.PostIncrement : UnaryOperatorType.PostDecrement;
}
else
{
type = (assignment.Operator == AssignmentOperatorType.Add) ? UnaryOperatorType.Increment : UnaryOperatorType.Decrement;
}
assignment.ReplaceWith(new UnaryOperatorExpression(type, assignment.Left.Detach()).CopyAnnotationsFrom(assignment).WithAnnotation(assignment.GetAllRecursiveILRanges()));
}
}
}
return(null);
}