protected internal override Expression VisitCorrelated(CorrelatedExpression node)
{
if (node.CorrelationId == _correlationId && node.Expression is AccumulatorExpression)
{
return Visit(node.Expression);
}
return base.VisitCorrelated(node);
}
private Expression VisitCorrelatedAccumulator(CorrelatedExpression node)
{
Expression mapped;
if (_accumulatorReplacementMap.TryGetValue(node, out mapped))
{
return mapped;
}
return base.VisitCorrelated(node);
}
protected internal override Expression VisitCorrelated(CorrelatedExpression node)
{
if (node.Expression is AccumulatorExpression)
{
return VisitCorrelatedAccumulator(node);
}
if (node.Expression is GroupByExpression)
{
return VisitCorrelatedGroup(node);
}
return base.VisitCorrelated(node);
}
private Expression VisitCorrelatedGroup(CorrelatedExpression node)
{
var groupExpression = (GroupByExpression)node.Expression;
if (_accumulatorLookup != null && _accumulatorLookup.Contains(node.CorrelationId))
{
var oldAccumulatorLookup = _accumulatorLookup;
var source = Visit(groupExpression.Source);
_accumulatorLookup = oldAccumulatorLookup;
var accumulators = new List<AccumulatorExpression>();
var fieldExpressions = new List<FieldExpression>();
var comparer = new ExpressionComparer();
foreach (var correlatedAccumulator in _accumulatorLookup[node.CorrelationId])
{
var index = accumulators.FindIndex(x => comparer.Compare((Expression)x, correlatedAccumulator.Expression));
FieldExpression fieldExpression;
if (index == -1)
{
var accumulator = (AccumulatorExpression)correlatedAccumulator.Expression;
// TODO: might not need to do any renames...
accumulator = new AccumulatorExpression(
accumulator.Type,
"__agg" + accumulators.Count,
accumulator.Serializer,
accumulator.AccumulatorType,
accumulator.Argument);
accumulators.Add(accumulator);
fieldExpression = new FieldExpression(accumulator.FieldName, accumulator.Serializer);
fieldExpressions.Add(fieldExpression);
}
else
{
fieldExpression = fieldExpressions[index];
}
_accumulatorReplacementMap[correlatedAccumulator] = fieldExpression;
}
groupExpression = new GroupByExpression(
groupExpression.Type,
source,
groupExpression.KeySelector,
accumulators.AsReadOnly());
}
return Visit(groupExpression);
}
protected internal virtual Expression VisitCorrelated(CorrelatedExpression node)
{
return(node.Update(Visit(node.Expression)));
}
protected internal virtual Expression VisitCorrelated(CorrelatedExpression node)
{
return node.Update(Visit(node.Expression));
}
protected internal override Expression VisitCorrelated(CorrelatedExpression node)
{
if (node.Expression is AccumulatorExpression)
{
_accumulators.Add(node);
return node;
}
return base.VisitCorrelated(node);
}
