/// <inheritdoc/>
protected override Provider VisitCalculate(CalculateProvider provider)
{
OnRecursionEntrance(provider);
var source = VisitCompilable(provider.Source);
OnRecursionExit(provider);
var translated = false;
var descriptors = new List <CalculatedColumnDescriptor>(provider.CalculatedColumns.Length);
foreach (var column in provider.CalculatedColumns)
{
var expression = translate(provider, column.Expression);
if (expression != column.Expression)
{
translated = true;
}
var ccd = new CalculatedColumnDescriptor(column.Name, column.Type, (Expression <Func <Tuple, object> >)expression);
descriptors.Add(ccd);
}
if (!translated && source == provider.Source)
{
return(provider);
}
return(new CalculateProvider(source, descriptors.ToArray()));
}
protected override Provider VisitCalculate(CalculateProvider provider)
{
int sourceLength = provider.Source.Header.Length;
var usedColumns = mappings[provider];
var sourceMapping = Merge(
mappings[provider].Where(i => i < sourceLength),
provider.CalculatedColumns.SelectMany(c => mappingsGatherer.Gather(c.Expression))
);
mappings[provider.Source] = sourceMapping;
var newSourceProvider = VisitCompilable(provider.Source);
mappings[provider] = mappings[provider.Source];
bool translated = false;
var descriptors = new List <CalculatedColumnDescriptor>(provider.CalculatedColumns.Length);
var currentMapping = mappings[provider];
for (int calculatedColumnIndex = 0; calculatedColumnIndex < provider.CalculatedColumns.Length; calculatedColumnIndex++)
{
if (usedColumns.Contains(provider.CalculatedColumns[calculatedColumnIndex].Index))
{
currentMapping.Add(provider.Source.Header.Length + calculatedColumnIndex);
var column = provider.CalculatedColumns[calculatedColumnIndex];
var expression = TranslateLambda(provider, column.Expression);
if (expression != column.Expression)
{
translated = true;
}
var ccd = new CalculatedColumnDescriptor(column.Name, column.Type, (Expression <Func <Tuple, object> >)expression);
descriptors.Add(ccd);
}
}
mappings[provider] = currentMapping;
if (descriptors.Count == 0)
{
return(newSourceProvider);
}
if (!translated && newSourceProvider == provider.Source && descriptors.Count == provider.CalculatedColumns.Length)
{
return(provider);
}
return(new CalculateProvider(newSourceProvider, descriptors.ToArray()));
}
