/// <summary>
/// Creates a <see cref="FrozenDictionary{TKey, TValue}"/> from an <see cref="IEnumerable{T}"/> according to specified key selector and value selector functions.
/// </summary>
/// <typeparam name="TSource"></typeparam>
/// <param name="source"></param>
/// <param name="keySelector"></param>
/// <param name="valueSelector"></param>
/// <returns></returns>
public static FrozenDictionary <TKey, TValue> Create <TSource>(IEnumerable <TSource> source, Func <TSource, TKey> keySelector, Func <TSource, TValue> valueSelector)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (keySelector == null)
{
throw new ArgumentNullException(nameof(keySelector));
}
if (valueSelector == null)
{
throw new ArgumentNullException(nameof(valueSelector));
}
const int initialSize = 4;
const float loadFactor = 0.75f;
var size = source.CountIfMaterialized() ?? initialSize;
var bucketSize = CalculateCapacity(size, loadFactor);
var result = new FrozenDictionary <TKey, TValue>(bucketSize, loadFactor);
foreach (var x in source)
{
var key = keySelector(x);
var value = valueSelector(x);
if (!result.TryAddInternal(key, value, out _))
{
throw new ArgumentException($"Key was already exists. Key:{key}");
}
}
return(result);
}
/// <summary>
/// Converts to <see cref="FrozenDictionary{TKey, TValue}"/>.
/// </summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TValue"></typeparam>
/// <param name="source"></param>
/// <param name="keySelector"></param>
/// <param name="valueSelector"></param>
/// <returns></returns>
public static FrozenDictionary <TKey, TValue> ToFrozenDictionary <TSource, TKey, TValue>(this IEnumerable <TSource> source, Func <TSource, TKey> keySelector, Func <TSource, TValue> valueSelector)
=> FrozenDictionary <TKey, TValue> .Create(source, keySelector, valueSelector);
