/// <summary>
/// Gets the row number in the C# 4.0 spec operator precedence table.
/// </summary>
static int GetPrecedence(Expression expr)
{
// Note: the operator precedence table on MSDN is incorrect
if (expr is QueryExpression)
{
// Not part of the table in the C# spec, but we need to ensure that queries within
// primary expressions get parenthesized.
return(QueryOrLambda);
}
UnaryOperatorExpression uoe = expr as UnaryOperatorExpression;
if (uoe != null)
{
if (uoe.Operator == UnaryOperatorType.PostDecrement || uoe.Operator == UnaryOperatorType.PostIncrement)
{
return(Primary);
}
else
{
return(Unary);
}
}
if (expr is CastExpression)
{
return(Unary);
}
BinaryOperatorExpression boe = expr as BinaryOperatorExpression;
if (boe != null)
{
switch (boe.Operator)
{
case BinaryOperatorType.Multiply:
case BinaryOperatorType.Divide:
case BinaryOperatorType.Modulus:
return(13); // multiplicative
case BinaryOperatorType.Add:
case BinaryOperatorType.Subtract:
return(12); // additive
case BinaryOperatorType.ShiftLeft:
case BinaryOperatorType.ShiftRight:
return(11);
case BinaryOperatorType.GreaterThan:
case BinaryOperatorType.GreaterThanOrEqual:
case BinaryOperatorType.LessThan:
case BinaryOperatorType.LessThanOrEqual:
return(RelationalAndTypeTesting);
case BinaryOperatorType.Equality:
case BinaryOperatorType.InEquality:
return(Equality);
case BinaryOperatorType.BitwiseAnd:
return(8);
case BinaryOperatorType.ExclusiveOr:
return(7);
case BinaryOperatorType.BitwiseOr:
return(6);
case BinaryOperatorType.ConditionalAnd:
return(5);
case BinaryOperatorType.ConditionalOr:
return(4);
case BinaryOperatorType.NullCoalescing:
return(3);
default:
throw new NotSupportedException("Invalid value for BinaryOperatorType");
}
}
if (expr is IsExpression || expr is AsExpression)
{
return(RelationalAndTypeTesting);
}
if (expr is ConditionalExpression)
{
return(Conditional);
}
if (expr is AssignmentExpression || expr is LambdaExpression)
{
return(Assignment);
}
// anything else: primary expression
return(Primary);
}
public virtual S VisitBinaryOperatorExpression(BinaryOperatorExpression binaryOperatorExpression, T data)
{
return(VisitChildren(binaryOperatorExpression, data));
}
