protected override Expression VisitBinaryExpression(BinaryExpression expression)
{
// handle special cases
if (expression.NodeType == ExpressionType.Equal)
{
if (HandleAddressOrIdEquals(expression.Left, expression.Right))
{
return(expression);
}
}
if (expression.NodeType == ExpressionType.Equal || expression.NodeType == ExpressionType.NotEqual)
{
if (HandleEqualsNotEquals(expression))
{
return(expression);
}
var leftPropertyHint = GetPropertyHint(expression.Left);
var rightPropertyHint = GetPropertyHint(expression.Right);
var leftIsAddress = leftPropertyHint != null &&
(leftPropertyHint.MappingType == PropertyMappingType.Address ||
leftPropertyHint.MappingType == PropertyMappingType.Id);
var rightIsAddress = rightPropertyHint != null &&
(rightPropertyHint.MappingType == PropertyMappingType.Address ||
rightPropertyHint.MappingType == PropertyMappingType.Id);
//handle checking for nulls (bug 5416)
/*
* if (rightPropertyHint == null && expression.Right.NodeType == ExpressionType.Constant)
* {
* var constantExpression = expression.Right as ConstantExpression;
* var value = constantExpression.Value;
* var defValue = expression.Left.Type.GetDefaultValue();
* if ((value == null && defValue == null) || (value != null && value.Equals(defValue)))
* {
* if (leftIsAddress)
* {
* var querySourceReferenceExpression =
* ((MemberExpression) expression.Left).Expression as QuerySourceReferenceExpression;
* var varname = querySourceReferenceExpression.ReferencedQuerySource.ItemName;
*
* var filter = expression.NodeType == ExpressionType.NotEqual
* ? "( bound(?{0}))"
* : "(!bound(?{0}))";
* _filterWriter.AppendFormat(filter, varname);
* return expression;
* }
* else
* {
* string varname = null;
* QueryBuilder.StartOptional();
* var convertedExpression = VisitExpression(expression.Left);
* QueryBuilder.EndOptional();
* if (convertedExpression is SelectVariableNameExpression)
* {
* varname = (convertedExpression as SelectVariableNameExpression).Name;
* }
* if (varname != null)
* {
* string filter;
* if (expression.Left.Type.IsValueType && defValue != null)
* {
* filter = expression.NodeType == ExpressionType.NotEqual
* ? "(bound(?{0}) && (?{0} != {1}))"
* : "(!bound(?{0}) || (?{0} = {1}))";
* }
* else
* {
* filter = expression.NodeType == ExpressionType.NotEqual
* ? "( bound(?{0}))"
* : "(!bound(?{0}))";
* }
* if (defValue != null)
* {
* _filterWriter.AppendFormat(filter, varname,
* _filterWriter.MakeSparqlConstant(defValue));
* }
* else
* {
* _filterWriter.AppendFormat(filter, varname);
* }
* return expression;
* }
* }
* }
* }
*
* if (leftIsAddress && expression.Right.NodeType == ExpressionType.Constant)
* {
* var querySourceReferenceExpression = ((MemberExpression)expression.Left).Expression as QuerySourceReferenceExpression;
* var varname = querySourceReferenceExpression.ReferencedQuerySource.ItemName;
*
* var constantExpression = expression.Right as ConstantExpression;
* var value = constantExpression.Value.ToString();
*
* var filter = expression.NodeType == ExpressionType.Equal
* ? "( sameTerm(?{0}, <{1}>))"
* : "(!sameTerm(?{0}, <{1}>))";
*
* _filterWriter.AppendFormat(filter, varname, MakeResourceAddress(GetPropertyInfo(expression.Right), value));
* return expression;
* }
*
* if (rightIsAddress && expression.Left.NodeType == ExpressionType.Constant)
* {
* var querySourceReferenceExpression =
* ((MemberExpression) expression.Right).Expression as QuerySourceReferenceExpression;
* var varname = querySourceReferenceExpression.ReferencedQuerySource.ItemName;
* var constantExpression = expression.Left as ConstantExpression;
* var value = constantExpression.Value.ToString();
* var filter = expression.NodeType == ExpressionType.Equal
* ? "(sameTerm(<{0}>,?{1}))"
* : "(!sameTerm(?{0}, <{1}>))";
* _filterWriter.AppendFormat(filter, MakeResourceAddress(GetPropertyInfo(expression.Left), value), varname);
* }
*/
if (leftIsAddress && rightIsAddress)
{
// Comparing two resource addresses - use the sameTerm function rather then simple equality
_filterWriter.Append(expression.NodeType == ExpressionType.Equal
? "(sameTerm("
: "(!sameTerm(");
_filterWriter.VisitExpression(expression.Left);
_filterWriter.Append(",");
_filterWriter.VisitExpression(expression.Right);
_filterWriter.Append("))");
return(expression);
}
}
var mce = expression.Left as MethodCallExpression;
if (mce != null && mce.Method.Name.Equals("Compare"))
{
//handle compare (bug 5441)
HandleCompareExpression(mce, expression.NodeType);
return(expression);
}
// Process operators that translate to SPARQL functions
switch (expression.NodeType)
{
case ExpressionType.Or:
_filterWriter.WriteFunction(BrightstarDB.Query.BrightstarFunctionFactory.BrightstarFunctionsNamespace, BrightstarDB.Query.BrightstarFunctionFactory.BitOr, expression.Left, expression.Right);
return(expression);
case ExpressionType.And:
_filterWriter.WriteFunction(BrightstarDB.Query.BrightstarFunctionFactory.BrightstarFunctionsNamespace, BrightstarDB.Query.BrightstarFunctionFactory.BitAnd, expression.Left, expression.Right);
return(expression);
}
// Process in-fix operator
_filterWriter.Append('(');
_filterWriter.VisitExpression(expression.Left);
switch (expression.NodeType)
{
case ExpressionType.Add:
case ExpressionType.AddChecked:
_filterWriter.Append(" + ");
break;
case ExpressionType.AndAlso:
_filterWriter.Append(" && ");
break;
case ExpressionType.Divide:
_filterWriter.Append(" / ");
break;
case ExpressionType.Equal:
_filterWriter.Append(" = ");
break;
case ExpressionType.GreaterThan:
_filterWriter.Append(" > ");
break;
case ExpressionType.GreaterThanOrEqual:
_filterWriter.Append(" >= ");
break;
case ExpressionType.LessThan:
_filterWriter.Append(" < ");
break;
case ExpressionType.LessThanOrEqual:
_filterWriter.Append(" <= ");
break;
case ExpressionType.Multiply:
case ExpressionType.MultiplyChecked:
_filterWriter.Append(" * ");
break;
case ExpressionType.NotEqual:
_filterWriter.Append(" != ");
break;
case ExpressionType.OrElse:
_filterWriter.Append(" || ");
break;
case ExpressionType.Subtract:
case ExpressionType.SubtractChecked:
_filterWriter.Append(" - ");
break;
default:
base.VisitBinaryExpression(expression);
break;
}
_filterWriter.VisitExpression(expression.Right);
_filterWriter.Append(')');
return(expression);
}
private Expression HandleBinaryExpression(BinaryExpression expression)
{
// handle special cases
if (expression.NodeType == ExpressionType.Equal)
{
if (HandleAddressOrIdEquals(expression.Left, expression.Right))
{
return(expression);
}
}
if (expression.NodeType == ExpressionType.Equal || expression.NodeType == ExpressionType.NotEqual)
{
if (HandleEqualsNotEquals(expression))
{
return(expression);
}
var leftPropertyHint = GetPropertyHint(expression.Left);
var rightPropertyHint = GetPropertyHint(expression.Right);
var leftIsAddress = leftPropertyHint != null &&
(leftPropertyHint.MappingType == PropertyMappingType.Address ||
leftPropertyHint.MappingType == PropertyMappingType.Id);
var rightIsAddress = rightPropertyHint != null &&
(rightPropertyHint.MappingType == PropertyMappingType.Address ||
rightPropertyHint.MappingType == PropertyMappingType.Id);
if (leftIsAddress && rightIsAddress)
{
// Comparing two resource addresses - use the sameTerm function rather then simple equality
_filterWriter.Append(expression.NodeType == ExpressionType.Equal
? "(sameTerm("
: "(!sameTerm(");
_filterWriter.VisitExpression(expression.Left);
_filterWriter.Append(",");
_filterWriter.VisitExpression(expression.Right);
_filterWriter.Append("))");
return(expression);
}
}
var mce = expression.Left as MethodCallExpression;
if (mce != null && mce.Method.Name.Equals("Compare"))
{
//handle compare (bug 5441)
HandleCompareExpression(mce, expression.NodeType);
return(expression);
}
// Process operators that translate to SPARQL functions
switch (expression.NodeType)
{
case ExpressionType.Or:
_filterWriter.WriteFunction(BrightstarFunctionFactory.BrightstarFunctionsNamespace,
BrightstarFunctionFactory.BitOr, expression.Left, expression.Right);
return(expression);
case ExpressionType.And:
_filterWriter.WriteFunction(BrightstarFunctionFactory.BrightstarFunctionsNamespace,
BrightstarFunctionFactory.BitAnd, expression.Left, expression.Right);
return(expression);
}
// Process in-fix operator
if (_optimizeFilter)
{
switch (expression.NodeType)
{
case ExpressionType.Equal:
QueryBuilder.StartBgpGroup();
AppendOptimisedEqualityExpression(expression.Left, expression.Right);
QueryBuilder.EndBgpGroup();
break;
case ExpressionType.NotEqual:
QueryBuilder.StartMinus();
AppendOptimisedEqualityExpression(expression.Left, expression.Right);
QueryBuilder.EndMinus();
break;
case ExpressionType.OrElse:
_inBooleanExpression = true;
QueryBuilder.StartBgpGroup();
VisitExpression(expression.Left);
QueryBuilder.EndBgpGroup();
QueryBuilder.Union();
QueryBuilder.StartBgpGroup();
VisitExpression(expression.Right);
QueryBuilder.EndBgpGroup();
_inBooleanExpression = false;
break;
case ExpressionType.AndAlso:
_inBooleanExpression = true;
VisitExpression(expression.Left);
VisitExpression(expression.Right);
_inBooleanExpression = false;
break;
default:
throw new NotSupportedException();
}
}
else
{
_filterWriter.Append('(');
_filterWriter.VisitExpression(expression.Left);
switch (expression.NodeType)
{
case ExpressionType.Add:
case ExpressionType.AddChecked:
_filterWriter.Append(" + ");
break;
case ExpressionType.AndAlso:
_filterWriter.Append(" && ");
break;
case ExpressionType.Divide:
_filterWriter.Append(" / ");
break;
case ExpressionType.Equal:
_filterWriter.Append(" = ");
break;
case ExpressionType.GreaterThan:
_filterWriter.Append(" > ");
break;
case ExpressionType.GreaterThanOrEqual:
_filterWriter.Append(" >= ");
break;
case ExpressionType.LessThan:
_filterWriter.Append(" < ");
break;
case ExpressionType.LessThanOrEqual:
_filterWriter.Append(" <= ");
break;
case ExpressionType.Multiply:
case ExpressionType.MultiplyChecked:
_filterWriter.Append(" * ");
break;
case ExpressionType.NotEqual:
_filterWriter.Append(" != ");
break;
case ExpressionType.OrElse:
_filterWriter.Append(" || ");
break;
case ExpressionType.Subtract:
case ExpressionType.SubtractChecked:
_filterWriter.Append(" - ");
break;
default:
base.VisitBinaryExpression(expression);
break;
}
_filterWriter.VisitExpression(expression.Right);
_filterWriter.Append(')');
}
return(expression);
}
