private Expression BindSelect(Type resultType, Expression source, LambdaExpression selector)
{
MetaProjectorExpression mp = AsProjection(Visit(source));
Expression projector = MapAndVisit(selector, mp);
return(new MetaProjectorExpression(resultType, projector));
}
protected virtual Expression BindJoin(Type resultType, Expression outerSource, Expression innerSource, LambdaExpression outerKey, LambdaExpression innerKey, LambdaExpression resultSelector)
{
MetaProjectorExpression mpOuter = AsProjection(Visit(outerSource));
MetaProjectorExpression mpInner = AsProjection(Visit(innerSource));
Expression projector = MapAndVisit(resultSelector, mpOuter, mpInner);
return(new MetaProjectorExpression(resultType, projector));
}
private Expression BindGroupBy(Type resultType, Expression source, LambdaExpression keySelector, LambdaExpression elementSelector)
{
MetaProjectorExpression mp = AsProjection(Visit(source));
Expression key = MapAndVisit(keySelector, mp);
Expression element = MapAndVisit(elementSelector, mp);
Type colType = typeof(IEnumerable <>).MakeGenericType(element.Type);
Type groupType = typeof(Grouping <,>).MakeGenericType(key.Type, element.Type);
return(new MetaProjectorExpression(resultType,
Expression.New(groupType.GetConstructor(new Type[] { key.Type, colType }),
key, new MetaProjectorExpression(colType, element))));
}
private Expression BindAggregate(Type resultType, AggregateSqlFunction aggregateFunction, Expression source, LambdaExpression selector)
{
MetaProjectorExpression mp = AsProjection(Visit(source));
if (selector == null)
{
return(mp.Projector);
}
Expression projector = MapAndVisit(selector, mp);
return(projector);
}
protected virtual Expression BindSelectMany(Type resultType, Expression source, LambdaExpression collectionSelector, LambdaExpression resultSelector)
{
MetaProjectorExpression mp = AsProjection(Visit(source));
MetaProjectorExpression collectionProjector = AsProjection(MapAndVisit(collectionSelector, mp));
if (resultSelector == null)
{
return(collectionProjector);
}
Expression resultProjection = MapAndVisit(resultSelector, mp, collectionProjector);
return(new MetaProjectorExpression(resultType, resultProjection));
}
public static MetaProjectorExpression AsProjection(Expression expression)
{
MetaProjectorExpression mpe = expression as MetaProjectorExpression;
if (mpe != null)
{
return((MetaProjectorExpression)mpe);
}
if (expression.NodeType == ExpressionType.New)
{
NewExpression nex = (NewExpression)expression;
if (nex.Type.IsInstantiationOf(typeof(Grouping <,>)))
{
return((MetaProjectorExpression)nex.Arguments[1]);
}
}
Type elementType = expression.Type.ElementType();
if (elementType != null)
{
MetaExpression meta = expression as MetaExpression;
if (meta != null && meta.Meta is CleanMeta)
{
PropertyRoute route = ((CleanMeta)meta.Meta).PropertyRoutes.SingleEx(() => "PropertyRoutes for {0}. Metas don't work over polymorphic MLists".FormatWith(meta.Meta)).Add("Item");
return(new MetaProjectorExpression(expression.Type,
new MetaExpression(elementType,
new CleanMeta(route.TryGetImplementations(), route))));
}
return(new MetaProjectorExpression(expression.Type,
MakeVoidMeta(elementType)));
}
throw new InvalidOperationException();
}
