public override ExpressionNode VisitUnaryExpression(UnaryExpression expression)
{
base.VisitUnaryExpression (expression);
ConstantExpression operandAsConstant = expression.Operand as ConstantExpression;
if (operandAsConstant != null)
{
// Ok, lets compute the result
if (operandAsConstant.IsNullValue)
return LiteralExpression.FromTypedNull(expression.ExpressionType);
try
{
return LiteralExpression.FromTypedValue(expression.GetValue(), expression.ExpressionType);
}
catch (RuntimeException ex)
{
_errorReporter.CannotFoldConstants(ex);
}
}
// If we getting here we return the orginal one.
return expression;
}
public override ExpressionNode VisitUnaryExpression(UnaryExpression expression)
{
base.VisitUnaryExpression(expression);
Type operandType = expression.Operand.ExpressionType;
if (operandType == null)
{
expression.OperatorMethod = null;
}
else
{
expression.OperatorMethod = _binder.BindOperator(expression.Op, operandType);
if (expression.OperatorMethod == null)
_errorReporter.CannotApplyOperator(expression.Op, operandType);
}
return expression;
}
public override AstElement Clone(Dictionary<AstElement, AstElement> alreadyClonedElements)
{
UnaryExpression result = new UnaryExpression(_op, (ExpressionNode)_operand.Clone(alreadyClonedElements));
result.OperatorMethod = OperatorMethod;
return result;
}
private static bool VisitUnaryExpression(UnaryExpression node1, UnaryExpression node2)
{
return node2 != null &&
node1.Op == node2.Op &&
Visit(node1.Operand, node2.Operand);
}
public override ExpressionNode VisitUnaryExpression(UnaryExpression expression)
{
_writer.Write(expression.Op.TokenText);
_writer.Write(" ");
bool parenthesesNeeded = NeedParentheses(expression.Operand, expression.Op.Precedence, false);
if (parenthesesNeeded)
_writer.Write("(");
Visit(expression.Operand);
if (parenthesesNeeded)
_writer.Write(")");
return expression;
}
private ExpressionNode ParseSubExpression(ExpressionNode left, int precedence)
{
if (left == null)
{
// No left operand, so we parse one and take care about leading unary operators
if (_token.Info.UnaryOperator != null)
{
UnaryOperator op = _token.Info.UnaryOperator;
NextToken();
ExpressionNode expr = ParseSubExpression(null, op.Precedence);
left = new UnaryExpression(op, expr);
}
else
{
left = ParseSimpleExpression();
}
}
while (_token.Id != TokenId.Eof)
{
// Special handling for NOT BETWEEN, NOT IN, NOT LIKE, NOT SIMILAR TO, and NOT SOUNDSLIKE.
bool negated = false;
if (_token.Id == TokenId.NOT)
{
if (_lookahead.Id == TokenId.BETWEEN ||
_lookahead.Id == TokenId.IN ||
_lookahead.Id == TokenId.LIKE ||
_lookahead.Id == TokenId.SIMILAR ||
_lookahead.Id == TokenId.SOUNDSLIKE)
{
NextToken();
negated = true;
}
}
// Special handling for the only ternary operator BETWEEN
if (_token.Id == TokenId.BETWEEN)
{
NextToken();
ExpressionNode lowerBound = ParseSubExpression(null, Operator.BETWEEN_PRECEDENCE);
Match(TokenId.AND);
ExpressionNode upperBound = ParseSubExpression(null, Operator.BETWEEN_PRECEDENCE);
left = new BetweenExpression(left, lowerBound, upperBound);
}
else
{
// If there is no binary operator we are finished
if (_token.Info.BinaryOperator == null)
break;
BinaryOperator binaryOp = _token.Info.BinaryOperator;
// Precedence is lower, parse it later
if (binaryOp.Precedence < precedence)
break;
// Precedence is equal, but operator ist not right associative, parse it later
if (binaryOp.Precedence == precedence && !binaryOp.IsRightAssociative)
break;
// Precedence is higher
NextToken();
// Special handling for SIMILAR TO
if (binaryOp == BinaryOperator.SimilarTo)
Match(TokenId.TO);
if (binaryOp == BinaryOperator.In)
{
// Special handling for IN
InExpression inExpression = new InExpression();
inExpression.Left = left;
inExpression.RightExpressions = ParseSimpleQueryExpressionList();
left = inExpression;
}
else if (_token.Id == TokenId.ANY || _token.Id == TokenId.SOME || _token.Id == TokenId.ALL)
{
// Special handling for ANY (SOME) and ALL
if (binaryOp != BinaryOperator.Equal &&
binaryOp != BinaryOperator.NotEqual &&
binaryOp != BinaryOperator.Less &&
binaryOp != BinaryOperator.LessOrEqual &&
binaryOp != BinaryOperator.Greater &&
binaryOp != BinaryOperator.GreaterOrEqual)
{
_errorReporter.InvalidOperatorForAllAny(_token.Range, binaryOp);
}
AllAnySubselect allAnySubselect = new AllAnySubselect();
allAnySubselect.Left = left;
allAnySubselect.Op = binaryOp;
allAnySubselect.Type = (_token.Id == TokenId.ALL) ? AllAnySubselect.AllAnyType.All : AllAnySubselect.AllAnyType.Any;
NextToken();
Match(TokenId.LeftParentheses);
allAnySubselect.Query = ParseQuery();
Match(TokenId.RightParentheses);
left = allAnySubselect;
}
else
{
left = new BinaryExpression(binaryOp, left, ParseSubExpression(null, binaryOp.Precedence));
}
}
// Special handling for negated expressions (see above)
if (negated)
left = new UnaryExpression(UnaryOperator.LogicalNot, left);
}
return left;
}
public override ExpressionNode VisitUnaryExpression(UnaryExpression expression)
{
// First visit arguments
base.VisitUnaryExpression(expression);
if (expression.Op == UnaryOperator.LogicalNot)
{
// Replace "NOT NOT expr" by "expr"
UnaryExpression unOp = expression.Operand as UnaryExpression;
if (unOp != null)
{
if (unOp.Op == UnaryOperator.LogicalNot)
return VisitExpression(unOp.Operand);
}
// Replace "NOT expr IS NULL" and "NOT expr IS NOT NULL" by
// "expr IS NOT NULL" and "expr IS NULL" resp.
IsNullExpression isNull = expression.Operand as IsNullExpression;
if (isNull != null)
{
isNull.Negated = !isNull.Negated;
return VisitExpression(isNull);
}
// Apply negation on EXISTS
ExistsSubselect existsSubselect = expression.Operand as ExistsSubselect;
if (existsSubselect != null)
{
existsSubselect.Negated = !existsSubselect.Negated;
return existsSubselect;
}
// Apply negation on ALL/ANY subquery
AllAnySubselect allAnySubselect = expression.Operand as AllAnySubselect;
if (allAnySubselect != null)
{
allAnySubselect.Op = AstUtil.NegateBinaryOp(allAnySubselect.Op);
allAnySubselect.Type = (allAnySubselect.Type == AllAnySubselect.AllAnyType.All) ? AllAnySubselect.AllAnyType.Any : AllAnySubselect.AllAnyType.All;
return allAnySubselect;
}
// Apply De Morgan's law
BinaryExpression binOp = expression.Operand as BinaryExpression;
if (binOp != null)
{
BinaryOperator negatedOp = AstUtil.NegateBinaryOp(binOp.Op);
if (negatedOp != null)
{
ExpressionNode newLeft;
ExpressionNode newRight;
if (binOp.Op == BinaryOperator.LogicalAnd || binOp.Op == BinaryOperator.LogicalOr)
{
newLeft = new UnaryExpression(expression.Op, binOp.Left);
newRight = new UnaryExpression(expression.Op, binOp.Right);
}
else
{
newLeft = binOp.Left;
newRight = binOp.Right;
}
binOp.Op = negatedOp;
binOp.Left = newLeft;
binOp.Right = newRight;
return VisitExpression(binOp);
}
}
}
return expression;
}
public void PushUnary(UnaryOperator unaryOperator)
{
ExpressionNode operand = _expressionStack.Pop();
UnaryExpression unaryExpression = new UnaryExpression(unaryOperator, operand);
Push(unaryExpression);
}
public virtual ExpressionNode VisitUnaryExpression(UnaryExpression expression)
{
expression.Operand = VisitExpression(expression.Operand);
return expression;
}
public override ExpressionNode VisitUnaryExpression(UnaryExpression expression)
{
EmitCall(expression.OperatorMethod, null, expression.Operand);
return expression;
}
public override ExpressionNode VisitUnaryExpression(UnaryExpression expression)
{
// First visit arguments
base.VisitUnaryExpression(expression);
if (expression.Op == UnaryOperator.LogicalNot)
{
// Replace "NOT NOT expr" by "expr"
UnaryExpression unOp = expression.Operand as UnaryExpression;
if (unOp != null)
{
if (unOp.Op == UnaryOperator.LogicalNot)
{
return(VisitExpression(unOp.Operand));
}
}
// Replace "NOT expr IS NULL" and "NOT expr IS NOT NULL" by
// "expr IS NOT NULL" and "expr IS NULL" resp.
IsNullExpression isNull = expression.Operand as IsNullExpression;
if (isNull != null)
{
isNull.Negated = !isNull.Negated;
return(VisitExpression(isNull));
}
// Apply negation on EXISTS
ExistsSubselect existsSubselect = expression.Operand as ExistsSubselect;
if (existsSubselect != null)
{
existsSubselect.Negated = !existsSubselect.Negated;
return(existsSubselect);
}
// Apply negation on ALL/ANY subquery
AllAnySubselect allAnySubselect = expression.Operand as AllAnySubselect;
if (allAnySubselect != null)
{
allAnySubselect.Op = AstUtil.NegateBinaryOp(allAnySubselect.Op);
allAnySubselect.Type = (allAnySubselect.Type == AllAnySubselect.AllAnyType.All) ? AllAnySubselect.AllAnyType.Any : AllAnySubselect.AllAnyType.All;
return(allAnySubselect);
}
// Apply De Morgan's law
BinaryExpression binOp = expression.Operand as BinaryExpression;
if (binOp != null)
{
BinaryOperator negatedOp = AstUtil.NegateBinaryOp(binOp.Op);
if (negatedOp != null)
{
ExpressionNode newLeft;
ExpressionNode newRight;
if (binOp.Op == BinaryOperator.LogicalAnd || binOp.Op == BinaryOperator.LogicalOr)
{
newLeft = new UnaryExpression(expression.Op, binOp.Left);
newRight = new UnaryExpression(expression.Op, binOp.Right);
}
else
{
newLeft = binOp.Left;
newRight = binOp.Right;
}
binOp.Op = negatedOp;
binOp.Left = newLeft;
binOp.Right = newRight;
return(VisitExpression(binOp));
}
}
}
return(expression);
}
public override ExpressionNode VisitUnaryExpression(UnaryExpression expression)
{
_xmlWriter.WriteStartElement("unaryExpression");
_xmlWriter.WriteAttributeString("operator", expression.Op.TokenText);
Visit(expression.Operand);
_xmlWriter.WriteEndElement();
return expression;
}