private Expression MakeSelect(CurrentDependencies current, LambdaExpression selector)
{
var subExtractor = new DependenciesExtractor(selector, parameters.Concat(selector.Parameters));
LambdaExpression[] primarySubDependencies;
LambdaExpression[] additionalSubDependencies;
subExtractor.Extract(out primarySubDependencies, out additionalSubDependencies);
var prefixCurrent = MakeLambda(GotoCurrent(current.Prefix));
current.AddSubDependencies(prefixCurrent, additionalSubDependencies);
if (primarySubDependencies.Length > 1)
{
return(Expression.NewArrayInit(typeof(object), primarySubDependencies.Select(exp => Expression.Convert(prefixCurrent.Merge(exp).Body, typeof(object)))));
}
var primarySubDependency = primarySubDependencies.SingleOrDefault();
if (primarySubDependency == null)
{
return(Expression.NewArrayInit(typeof(object)));
}
if (!selector.ReturnType.IsAssignableFrom(primarySubDependency.ReturnType))
{
return(null);
}
if (!(primarySubDependency.Body is NewExpression))
{
return(new AnonymousTypeEliminator().Eliminate(prefixCurrent.Merge(primarySubDependency)).Body);
}
var newExpression = (NewExpression)primarySubDependency.Body;
return(Expression.New(newExpression.Constructor, newExpression.Arguments.Select(arg => prefixCurrent.Merge(Expression.Lambda(arg, primarySubDependency.Parameters)).Body)));
}
private void ProcessLinqSelectMany(MethodInfo method, CurrentDependencies current, Expression[] arguments)
{
var collectionSelector = (LambdaExpression)arguments[0];
var collection = MakeSelect(current, collectionSelector);
if (collection == null)
{
current.Prefix = null;
return;
}
if (arguments.Length == 1)
{
current.Prefix = collection;
return;
}
var resultSelector = (LambdaExpression)arguments[1];
var subExtractor = new DependenciesExtractor(resultSelector, parameters.Concat(resultSelector.Parameters));
LambdaExpression[] primarySubDependencies;
LambdaExpression[] additionalSubDependencies;
subExtractor.Extract(out primarySubDependencies, out additionalSubDependencies);
var prefixCurrent = MakeLambda(GotoCurrent(current.Prefix));
var collectionCurrent = MakeLambda(GotoCurrent(collection));
current.AddSubDependencies(prefixCurrent, collectionCurrent, additionalSubDependencies);
var primarySubDependency = primarySubDependencies.Single();
if (!(primarySubDependency.Body is NewExpression))
{
current.Prefix = new AnonymousTypeEliminator().Eliminate(new ExpressionMerger(prefixCurrent, collectionCurrent).Merge(primarySubDependency)).Body;
}
else
{
var newExpression = (NewExpression)primarySubDependency.Body;
current.Prefix = Expression.New(newExpression.Constructor, newExpression.Arguments.Select(arg => new ExpressionMerger(prefixCurrent, collectionCurrent).Merge(Expression.Lambda(arg, primarySubDependency.Parameters)).Body));
}
}
