internal static LookupDefaultEnumerable <TKey, TItem> ToLookupImpl <TItem, TKey, TEnumerator>(
ref TEnumerator source,
Func <TItem, TKey> keySelector
)
where TEnumerator : struct, IStructEnumerator <TItem>
{
var hashtable = new LookupHashtable <TKey, TItem>();
hashtable.Initialize();
while (source.MoveNext())
{
var item = source.Current;
var key = keySelector(item);
hashtable.Add(key, item);
}
return(new LookupDefaultEnumerable <TKey, TItem>(ref hashtable));
}
internal static LookupDefaultEnumerable <TKey, TElement> ToLookupImpl <TItem, TKey, TElement, TEnumerable, TEnumerator>(
ref TEnumerable source,
Func <TItem, TKey> keySelector,
Func <TItem, TElement> elementSelector
)
where TEnumerable : struct, IStructEnumerable <TItem, TEnumerator>
where TEnumerator : struct, IStructEnumerator <TItem>
{
var hashtable = new LookupHashtable <TKey, TElement>();
hashtable.Initialize();
foreach (var item in source)
{
var key = keySelector(item);
var element = elementSelector(item);
hashtable.Add(key, element);
}
return(new LookupDefaultEnumerable <TKey, TElement>(ref hashtable));
}
internal static LookupSpecificEnumerable <TKey, TItem> ToLookupImpl <TItem, TKey, TEnumerator>(
ref TEnumerator source,
Func <TItem, TKey> keySelector,
IEqualityComparer <TKey> comparer
)
where TEnumerator : struct, IStructEnumerator <TItem>
{
comparer = comparer ?? EqualityComparer <TKey> .Default;
var hashtable = new LookupHashtable <TKey, TItem>();
hashtable.Initialize();
while (source.MoveNext())
{
var item = source.Current;
var key = keySelector(item);
hashtable.Add(key, item, comparer);
}
return(new LookupSpecificEnumerable <TKey, TItem>(ref hashtable, comparer));
}
internal static LookupSpecificEnumerable <TKey, TElement> ToLookupImpl <TItem, TKey, TElement, TEnumerable, TEnumerator>(
ref TEnumerable source,
Func <TItem, TKey> keySelector,
Func <TItem, TElement> elementSelector,
IEqualityComparer <TKey> comparer
)
where TEnumerable : struct, IStructEnumerable <TItem, TEnumerator>
where TEnumerator : struct, IStructEnumerator <TItem>
{
comparer = comparer ?? EqualityComparer <TKey> .Default;
var hashtable = new LookupHashtable <TKey, TElement>();
hashtable.Initialize();
foreach (var item in source)
{
var key = keySelector(item);
var element = elementSelector(item);
hashtable.Add(key, element, comparer);
}
return(new LookupSpecificEnumerable <TKey, TElement>(ref hashtable, comparer));
}
