// This helper is a workaround for the fact that Enum.Defined() does not work on non-public enums.
// There is a custom attribute in System.Reflection.Metadata.Controls that would make it work
// but we don't want to introduce a dependency on that contract just to support two asserts.
public static bool IsValidQueryAggregationOption(this QueryAggregationOptions value)
{
return(value == QueryAggregationOptions.None ||
value == QueryAggregationOptions.Associative ||
value == QueryAggregationOptions.Commutative ||
value == QueryAggregationOptions.AssociativeCommutative);
}
//---------------------------------------------------------------------------------------
// Constructs a new instance of an associative operator.
//
// Assumptions:
// This operator must be associative.
//
internal AssociativeAggregationOperator(IEnumerable <TInput> child, TIntermediate seed, Func <TIntermediate> seedFactory, bool seedIsSpecified,
Func <TIntermediate, TInput, TIntermediate> intermediateReduce,
Func <TIntermediate, TIntermediate, TIntermediate> finalReduce,
Func <TIntermediate, TOutput> resultSelector, bool throwIfEmpty, QueryAggregationOptions options)
: base(child)
{
Contract.Assert(child != null, "child data source cannot be null");
Contract.Assert(intermediateReduce != null, "need an intermediate reduce function");
Contract.Assert(finalReduce != null, "need a final reduce function");
Contract.Assert(resultSelector != null, "need a result selector function");
Contract.Assert(options.IsValidQueryAggregationOption(), "enum out of valid range");
Contract.Assert((options & QueryAggregationOptions.Associative) == QueryAggregationOptions.Associative, "expected an associative operator");
Contract.Assert(typeof(TIntermediate) == typeof(TInput) || seedIsSpecified, "seed must be specified if TIntermediate differs from TInput");
_seed = seed;
_seedFactory = seedFactory;
_seedIsSpecified = seedIsSpecified;
_intermediateReduce = intermediateReduce;
_finalReduce = finalReduce;
_resultSelector = resultSelector;
_throwIfEmpty = throwIfEmpty;
}
internal AssociativeAggregationOperator(IEnumerable <TInput> child, TIntermediate seed, Func <TIntermediate> seedFactory, bool seedIsSpecified, Func <TIntermediate, TInput, TIntermediate> intermediateReduce, Func <TIntermediate, TIntermediate, TIntermediate> finalReduce, Func <TIntermediate, TOutput> resultSelector, bool throwIfEmpty, QueryAggregationOptions options) : base(child)
{
this.m_seed = seed;
this.m_seedFactory = seedFactory;
this.m_seedIsSpecified = seedIsSpecified;
this.m_intermediateReduce = intermediateReduce;
this.m_finalReduce = finalReduce;
this.m_resultSelector = resultSelector;
this.m_throwIfEmpty = throwIfEmpty;
}
