public TAccumulate Aggregate <TAccumulate>(TAccumulate seed, Expression <Func <TAccumulate, TSource, TAccumulate> > func)
{
var foundParameters = NakedParameterReferenceVisitor.GetParameters(func.Body);
if (foundParameters.Any(param => ReferenceEquals(param, func.Parameters[1])))
{
throw new InvalidOperationException("A reference to a deserialized type found in the select clause. Currently, only aggregations selecting type fields are allowed.");
}
var visitor = new MemberInfoGatheringVisitor(typeof(TSource));
visitor.Visit(_whereClause);
visitor.Visit(func);
var members = visitor.Members.Distinct().OrderBy(mi => mi.Name).ToArray();
var typeDeserialized = GetTypeReplacingTSource(typeof(TDeserialized), members);
var typeWithReducedMembers = GetTypeReplacingTSource(typeof(TSource), members);
var newDeserializedItemParam = Expression.Parameter(typeWithReducedMembers);
// build new where clause, with a parameter of reduced number of ValueMembers
var newWhere = BuildNewWhere(typeWithReducedMembers, newDeserializedItemParam);
// build new selector, with a parameter of reduced number of ValueMembers
var newFuncType = typeof(Func <, ,>).MakeGenericType(typeof(TAccumulate), typeWithReducedMembers, typeof(TAccumulate));
var newSelectorBody = ParameterReplacingVisitor.ReplaceParameter(func.Body, func.Parameters[1], newDeserializedItemParam);
var newSelector = Expression.Lambda(newFuncType, newSelectorBody, func.Parameters[0], newDeserializedItemParam).Compile();
var aggregatorType = typeof(ProtoLinqAggregator <, ,>).MakeGenericType(typeDeserialized, typeWithReducedMembers, typeof(TAccumulate));
var aggregator = (IAggregator <TAccumulate>)aggregatorType.GetConstructors()[0].Invoke(new object[] { _model, _options, _source, seed, newWhere, newSelector });
return(aggregator.Aggregate());
}
public IEnumerable <TResult> Select <TResult>(Expression <Func <TSource, int, TResult> > selector)
{
var foundParameters = NakedParameterReferenceVisitor.GetParameters(selector.Body);
if (foundParameters.Any(param => ReferenceEquals(param, selector.Parameters[0])))
{
throw new InvalidOperationException("A reference to a deserialized type found in the select clause. Currently, only projections selecting type fields are allowed.");
}
var visitor = new MemberInfoGatheringVisitor(typeof(TSource));
visitor.Visit(_whereClause);
visitor.Visit(selector);
var members = visitor.Members.Distinct().OrderBy(mi => mi.Name).ToArray();
var typeDeserialized = GetTypeReplacingTSource(typeof(TDeserialized), members);
var typeWithReducedMembers = GetTypeReplacingTSource(typeof(TSource), members);
var newDeserializedItemParam = Expression.Parameter(typeWithReducedMembers);
// build new where clause, with a parameter of reduced number of ValueMembers
var newWhere = BuildNewWhere(typeWithReducedMembers, newDeserializedItemParam);
// build new selector, with a parameter of reduced number of ValueMembers
var newSelectorType = typeof(Func <, ,>).MakeGenericType(typeWithReducedMembers, typeof(int), typeof(TResult));
var newSelectorBody = ParameterReplacingVisitor.ReplaceParameter(selector.Body, selector.Parameters[0], newDeserializedItemParam);
var newSelector = Expression.Lambda(newSelectorType, newSelectorBody, newDeserializedItemParam, selector.Parameters[1]).Compile();
var enumerableType = typeof(ProtoLinqEnumerable <, ,>).MakeGenericType(typeDeserialized, typeWithReducedMembers, typeof(TResult));
return((IEnumerable <TResult>)enumerableType.GetConstructors()[0].Invoke(new object[] { _model, _options, _source, newWhere, newSelector }));
}
private Delegate BuildNewWhere(Type typeWithReducedMembers, ParameterExpression newDeserializedItemParam)
{
var newPredicateType = typeof(Func <, ,>).MakeGenericType(typeWithReducedMembers, typeof(int), typeof(bool));
var newPredicateBody = ParameterReplacingVisitor.ReplaceParameter(_whereClause.Body, WhereItemParam,
newDeserializedItemParam);
return(Expression.Lambda(newPredicateType, newPredicateBody, newDeserializedItemParam, WhereIndexParam).Compile());
}
public IProtobufSimpleQueryable <TSource> Where(Expression <Func <TSource, int, bool> > predicate)
{
var body = predicate.Body;
body = ParameterReplacingVisitor.ReplaceParameter(body, predicate.Parameters[0], WhereItemParam);
body = ParameterReplacingVisitor.ReplaceParameter(body, predicate.Parameters[1], WhereIndexParam);
var combinedWhere = Expression.Lambda <Func <TSource, int, bool> >(Expression.And(_whereClause.Body, body), _whereClause.Parameters);
return(new ProtobufQueryable <TDeserialized, TSource>(_model, _source, _options, combinedWhere));
}
