static public HashSet <T> ToHashSet <T>(this IEnumerable <T> enumerable, ConservedKey conservedKey)
{
var hashSet = new HashSet <T>();
foreach (T obj in enumerable)
{
switch (conservedKey)
{
case ConservedKey.FirstOccurence:
hashSet.Add(obj);
break;
case ConservedKey.LastOccurence:
hashSet.Remove(obj);
hashSet.Add(obj);
break;
default: throw new NotSupportedException();
}
}
return(hashSet);
}
static public Dictionary <T1, T2> ToDictionary <T1, T2>(this IEnumerable <Tuple <T1, T2> > enumerable, ConservedKey conservedKey)
{
return(enumerable.ToDictionary(x => x.Item1, x => x.Item2, conservedKey));
}
static public Dictionary <TKey, TValue> ToDictionary <T, TKey, TValue>(this IEnumerable <T> enumerable, Func <T, TKey> keySelector, Func <T, TValue> valueSelector, ConservedKey conservedKey)
{
var dictionary = new Dictionary <TKey, TValue>();
foreach (T obj in enumerable)
{
TKey key = keySelector(obj);
switch (conservedKey)
{
case ConservedKey.FirstOccurence:
if (dictionary.ContainsKey(key))
{
dictionary.Add(key, valueSelector(obj));
}
break;
case ConservedKey.LastOccurence:
dictionary[key] = valueSelector(obj);
break;
default: throw new NotSupportedException();
}
}
return(dictionary);
}
static public Dictionary <TKey, TValue> ToDictionary <TKey, TValue>(this IEnumerable <KeyValuePair <TKey, TValue> > enumerable, ConservedKey conservedKey)
{
return(enumerable.ToDictionary(x => x.Key, x => x.Value, conservedKey));
}
