public static T?Find <T>(this IEnumerable <T> ts, Func <T, bool> pred, RequireStruct <T> _ = null) where T : struct
{
try
{
return(ts.First(pred));
}
catch (InvalidOperationException)
{
return(null);
}
}
public static void EnqueueId <T>(this IBackgroundTaskQueue <VmEntityStateMessage> queue,
string senderId, T entityId, string entityType, EntityOperation operation,
RequireStruct <T> ignore = null)
where T : struct
{
queue.Enqueue(new VmEntityStateMessage
{
SenderId = senderId,
EntityIds = new object[] { entityId },
EntityType = entityType,
Operation = operation
});
}
/// <summary>
/// Возвращает если элементов в перечислении values в кол-ве не 1 - mull
/// или значение, содержащееся в первом и единственном элементе.
/// </summary>
/// <param name="values">Обычно значение полученное из NullableToEnumerable и цепочки преобразований</param>
/// <returns>Единичное значение или null</returns>
public static T?SingleOrNull <T>(this IEnumerable <T> values, RequireStruct <T> ignoredArg = null) where T : struct
{
T?result = null;
foreach (var value in values)
{
if (result.HasValue)
{
return(null);
}
result = value;
}
return(result);
}
/// <summary>
/// Возвращает для входного параметра с пустым перечислителем IEnumerable mull
/// или значение, содержащееся в первом элементе.
/// </summary>
/// <param name="values">Обычно значение полученное из NullableToEnumerable и цепочки преобразований</param>
/// <returns>Единичное значение или null</returns>
public static T?FirstOrNull <T>(this IEnumerable <T> values, RequireStruct <T> ignoredArg = null) where T : struct
{
return(values.Select(_ => (T?)_).DefaultIfEmpty(null).FirstOrDefault());
}
public static Nullable <TResult> SelectMany <T, TMid, TResult>(this NullableOf <T> @this, Func <T, Nullable <TMid> > midSelector, Func <T, TMid, TResult> resultSelector, RequireStruct <TResult> _ = default(RequireStruct <TResult>))
where T : class
where TMid : struct
where TResult : struct
{
if ([email protected])
{
return(default(Nullable <TResult>));
}
var mid = midSelector((T)@this);
if (!mid.HasValue)
{
return(default(Nullable <TResult>));
}
return(resultSelector((T)@this, (TMid)mid));
}
public static Nullable <TResult> Select <T, TResult>(this Nullable <T> @this, Func <T, TResult> func, RequireStruct <TResult> _ = default(RequireStruct <TResult>))
where T : struct
where TResult : struct
{
return(@this.HasValue ? func((T)@this) : default(Nullable <TResult>));
}
public static TSource FirstOrDefault_ <TSource>(this IEnumerable <TSource> source, RequireStruct <TSource> _ = default)
where TSource : struct
{
return(Enumerable.FirstOrDefault(source));
}
public static TValue GetDef <TKey, TValue>(this Dictionary <TKey, TValue> dict, TKey key, TValue defValue = default(TValue), RequireStruct <TValue> PleaseIgnoreThisParameter = null)
where TValue : struct
{
if (!dict.ContainsKey(key))
{
return(defValue);
}
return(dict[key]);
}
public static Nullable <TSource> SingleOrNull <TSource>(this IEnumerable <TSource> source, Func <TSource, bool> predicate, RequireStruct <TSource> _ = default)
where TSource : struct
{
return(source.Where(predicate).SingleOrNull());
}
public static TSource SingleOrDefault_ <TSource>(this IEnumerable <TSource> source, Func <TSource, bool> predicate, RequireStruct <TSource> _ = default)
where TSource : struct
{
return(Enumerable.SingleOrDefault(source, predicate));
}
public static IEnumerable <Nullable <TSource> > NullIfEmpty <TSource>(this IEnumerable <TSource> source, RequireStruct <TSource> _ = default)
where TSource : struct
{
return(source.Select(x => (Nullable <TSource>)x).DefaultIfEmpty(null));
}
public static Nullable <TSource> SingleOrNull <TSource>(this IEnumerable <TSource> source, RequireStruct <TSource> _ = default)
where TSource : struct
{
return(Enumerable.SingleOrDefault(source.Select(x => (Nullable <TSource>)x)));
}
public static TValue SetSafe <TKey, TValue>(this Dictionary <TKey, TValue> dict, TKey key, TValue value, RequireStruct <TValue> PleaseIgnoreThisParameter = null)
where TValue : struct
{
if (!dict.ContainsKey(key))
{
dict.Add(key, value);
return(value);
}
return(dict[key] = value);
}
public TFinalType WithDummyVariable <TVariable>(Expression <Func <T, TVariable> > selector, TVariable?referrant = null,
RequireStruct <TVariable> reserved = null) where TVariable : struct =>
WithDummyVariable(ExpressionPrinter.Print(selector), selector.Compile(), referrant, reserved);
public static TSource ElementAtOrDefault_ <TSource>(this IEnumerable <TSource> source, int index, RequireStruct <TSource> _ = default)
where TSource : struct
{
return(Enumerable.ElementAtOrDefault(source, index));
}
public TFinalType WithDummyVariable <TVariable>(string name, Func <T, TVariable> selector, TVariable?referrant = null, RequireStruct <TVariable> reserved = null) where TVariable : struct => InnerWithDummyVariable(name, selector, referrant);
public static Nullable <TSource> ElementAtOrNull <TSource>(this IEnumerable <TSource> source, int index, RequireStruct <TSource> _ = default)
where TSource : struct
{
return(Enumerable.ElementAtOrDefault(source.Select(x => (Nullable <TSource>)x), index));
}
public static ChiSquaredStatisic ChiSquared <TD, TP1, TP2>(this IEnumerable <TD> data,
Func <TD, TP1> rows, Func <TD, TP2> cols, RequireStruct <TD> reserved = null) where TD : struct =>
data.Table().WithRows("", rows).WithColumns("", cols).ChiSquared();
public static ShimBuilderStruct <T> For <T>(RequireStruct <T> _ = null) where T : struct
{
return(default(ShimBuilderStruct <T>));
}
