public static ParseResult CreateAggregationKindsFromTokenList(IEnumerable <Token> tokenList, Field.Kind fieldKind, out List <Aggregation.Kinds> aggregationTypes)
{
aggregationTypes = new List <Aggregation.Kinds>();
foreach (var token in tokenList)
{
Aggregation.Kinds aggrType = Aggregation.Kinds.Undefined;
// check whether the aggregation type name exists
if (!SemanticsAnalyzer.CreateAggregationTypeFromName(token.Text, ref aggrType))
{
return(new ParseResult(ParseCode.SemanticsInvalidAggregationType, "Invalid aggregation type", token.ColumnPos));
}
// check whether the aggregation type is supported by the field type
if (!Field.IsAggregationAvailable(fieldKind, aggrType))
{
return(new ParseResult(ParseCode.SemanticsInvalidAggregationType, "Invalid aggregation type for the requested field type", token.ColumnPos));
}
aggregationTypes.Add(aggrType);
}
return(new ParseResult(ParseCode.Success));
}
public static bool IsAggregationAvailable(Kind fieldType, Aggregation.Kinds aggrType)
{
switch (fieldType)
{
case Kind.Property:
{
switch (aggrType)
{
case Aggregation.Kinds.Snapshot:
return(true);
case Aggregation.Kinds.Count:
return(true);
default:
return(false);
}
}
case Kind.Metric:
{
switch (aggrType)
{
case Aggregation.Kinds.Undefined:
return(false);
default:
return(true);
}
}
default:
return(false);
}
}
// Tries to translate the string describing into an Aggregation.Type
// if there is not corresponding aggregator return false to signal the semantic failure
public static bool CreateAggregationTypeFromName(string aggregationName, ref Aggregation.Kinds aggregationKind)
{
aggregationKind = Aggregation.CreateAggregationKindFromName(aggregationName);
if (aggregationKind == Aggregation.Kinds.Undefined)
{
return(false);
}
return(true);
}
