protected override Expression VisitGroupingExpression(GroupingExpression groupingExpression)
{
// 1. Prepare subquery parameters.
Parameter <Tuple> parameterOfTuple;
Type elementType;
ProjectionExpression projection;
var translatedQuery = PrepareSubqueryParameters(groupingExpression, out parameterOfTuple, out elementType, out projection);
// 2. Create constructor
var keyType = groupingExpression.KeyExpression.Type;
var keyMaterializer = Visit(groupingExpression.KeyExpression);
var groupingCtor = typeof(Grouping <,>)
.MakeGenericType(keyType, elementType)
.GetConstructor(new[] { typeof(ProjectionExpression), typeof(TranslatedQuery), typeof(Parameter <Tuple>), typeof(Tuple), keyType, typeof(ItemMaterializationContext) });
// 3. Create result expression.
var resultExpression = Expression.New(
groupingCtor,
Expression.Constant(projection),
Expression.Constant(translatedQuery),
Expression.Constant(parameterOfTuple),
tupleParameter,
keyMaterializer,
itemMaterializationContextParameter);
// 4. Result must be IGrouping<,> instead of Grouping<,>. Convert result expression.
return(Expression.Convert(resultExpression, groupingExpression.Type));
}
public object VisitGroupingExpression(GroupingExpression expr, object context)
{
StringBuilder.Append("(");
expr.Contents.AcceptVisitor(this, context);
StringBuilder.Append(")");
return(null);
}
protected override Expression VisitGroupingExpression(GroupingExpression expression)
{
var keyExpression = Visit(expression.KeyExpression);
if (keyExpression != expression.KeyExpression)
{
return(new GroupingExpression(
expression.Type,
expression.OuterParameter,
expression.DefaultIfEmpty,
expression.ProjectionExpression,
expression.ApplyParameter,
keyExpression,
expression.SelectManyInfo));
}
return(expression);
}
protected override Expression VisitGroupingExpression(GroupingExpression expression)
{
var newProvider = Rewrite(expression.ProjectionExpression.ItemProjector.DataSource, oldApplyParameter, newApplyParameter);
var newItemProjectorBody = Visit(expression.ProjectionExpression.ItemProjector.Item);
var newKeyExpression = Visit(expression.KeyExpression);
if (newProvider != expression.ProjectionExpression.ItemProjector.DataSource ||
newItemProjectorBody != expression.ProjectionExpression.ItemProjector.Item ||
newKeyExpression != expression.KeyExpression)
{
var newItemProjector = new ItemProjectorExpression(newItemProjectorBody, newProvider, expression.ProjectionExpression.ItemProjector.Context);
var newProjectionExpression = new ProjectionExpression(
expression.ProjectionExpression.Type,
newItemProjector,
expression.ProjectionExpression.TupleParameterBindings,
expression.ProjectionExpression.ResultType);
return(new GroupingExpression(
expression.Type, expression.OuterParameter, expression.DefaultIfEmpty, newProjectionExpression,
expression.ApplyParameter, expression.KeyExpression, expression.SelectManyInfo));
}
return(expression);
}
protected override Expression VisitGroupingExpression(GroupingExpression expression)
{
Visit(expression.KeyExpression);
VisitSubQueryExpression(expression);
return(expression);
}
protected override Expression VisitGroupingExpression(GroupingExpression expression)
{
return(expression);
}
public object VisitGroupingExpression(GroupingExpression expression)
{
Resolve(expression.Expression);
return(null);
}
public object VisitGroupingExpression(GroupingExpression expression)
{
return(Evaluate(expression.Expression));
}
protected virtual Expression VisitGroupingExpression(GroupingExpression expression)
{
return(expression);
}
public Unit VisitGroupingExpression(GroupingExpression expression)
{
Resolve(expression.Expression);
return(Unit.Value);
}
public string VisitGroupingExpression(GroupingExpression expression)
{
return(Parenthesize("group", expression.expression));
}
