DEV Community: .Net Trends

Type Unions for C# (aka discriminated unions)

.Net Trends — Sun, 28 Jul 2024 14:49:01 +0000

A long-desired feature in C# is now proposed in the C# community. Type Unions (aka discriminated unions) are specified in a new proposal of the language committee's official C# language repository. This proposal aims to bring a new level of flexibility and type safety to C#, enabling developers to write more expressive and resilient code.
Type Unions will probably be added in one of the next releases after C# 13, which is nearly complete and shipping in November 2024.

More details: https://dotnetrends.net/type-unions-discriminated.html

New LINQ methods coming in .NET 9

.Net Trends — Sat, 27 Jul 2024 10:57:31 +0000

CountBy
This is a pretty and very useful method and it is better explained with an example:

Before .NET 9

var roleCounts = users.GroupBy(user => user.Role) // Group users by their roles
    .Select(group => new { Role = group.Key, Count = group.Count() });

With .NET 9


var roleCounts = users.CountBy(user => user.Role);

AggregateBy
Use this new method instead of GroupBy to make the syntax clearer:
Before .NET 9

var levelSumByRole = users.GroupBy(user => user.Role)
    .Select(group => new { Role = group.Key, 
        SumByLevel = group.Sum(user => user.Level) });

With .NET 9

var levelSumByRole = users.AggregateBy(
    user => user.Role,
    seed: 0,
    (currentTotal, user) => currentTotal + user.AccessLevel);

Index
More convenient Linq method for getting value and index. Example:

foreach (var (index, item) in people.Index())
{
    Console.WriteLine($"Entry {index}: {item}");
}

The same can be achieved before .NET 9 with a more complex syntax:

foreach (var (item, index) in people.Select((item, index) => (item, index)))
{
    Console.WriteLine($"Entry {index}: {item}");
}

Note that the item and index are reversed with the Index method.

More: https://dotnetrends.net/new-linq-methods.html

This new Task.WhenEach API

.Net Trends — Mon, 01 Apr 2024 18:15:51 +0000

This new WhenEach API is 🔥. Really shows true composability of C#. No more complex WhenAny loops!

https://t.co/HWP804iXXF

Writing async/await from scratch in C# with Stephen Toub

.Net Trends — Mon, 01 Apr 2024 17:46:17 +0000

Demystify the world of asynchronous programming with .NET and specifically the magic behind async/await, learn from the best

https://t.co/G3e7h2vZLL