public static async Task <TResult> ToDictionaryAsync <TKey, TValue, TKeyDictionary, TValueDictionary, TResult>(this IEnumerableAsync <KeyValuePair <TKey, TValue> > kvpItems,
Func <KeyValuePair <TKey, TValue>, TKeyDictionary> selectKey,
Func <KeyValuePair <TKey, TValue>, TValueDictionary> selectValue,
Func <Dictionary <TKeyDictionary, TValueDictionary>, KeyValuePair <TKey, TValue>[], TResult> dictionaryAndDuplicates)
{
var hashSet = new HashSet <TKey>();
var kvpItemsArray = await kvpItems.ToArrayAsync();
var duplicates = new KeyValuePair <TKey, TValue>[] { };
var dictionary = kvpItemsArray
.Select(
kvp =>
{
if (hashSet.Contains(kvp.Key))
{
duplicates = duplicates.Append(kvp).ToArray();
return(default(KeyValuePair <TKeyDictionary, TValueDictionary>?));
}
hashSet.Add(kvp.Key);
return(selectValue(kvp).PairWithKey(selectKey(kvp)));
})
.SelectWhereHasValue()
.ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
return(dictionaryAndDuplicates(dictionary, duplicates));
}
public static async Task <IRefs <T> > AsRefsAsync <T>(this IEnumerableAsync <Guid> ids)
where T : IReferenceable
{
var idsArray = await ids.ToArrayAsync();
return(new Refs <T>(idsArray));
}