List initialization.... issue?

[ccarlo88]

Hello,

between all the absurd I have seen in the last years recently VS is asking me to change list initialization from
this:
List tables = new();
to this:
List tables = [];

So, my question is: Mixing up a list with an array stuff, is this a bug somehow or is it due to the Python developers not being satisfied enough producing garbage in the Python language that now they want to destroy all other programming languages?

[sharpchen]

The [] syntax is a new feature from C# 12. See #5354
And the reason why vs raises the suggestion, it may be related to microsoft/vscode-dotnettools#419. If the project built with no error, that's not a bug because there's a preview version sdk in your machine for sure. If not, that's what confused me about the langVersion and SDKs.

[huoyaoyuan]

Collection expression in C# is more like std::initializer_list in C++. It can adapt for different collections to provide optimized creation for each collection. It can save people from memorizing new[] {}, new List(capacity), ImmutableArray.Create() for each collection type.

[tannergooding]

We have many developers heavily involved. This ranges from people who work directly on the .NET team, to MVPs, people who attend the major conferences (.NET Conf, Microsoft BUILD, MVP Summit, etc), to industry professionals, to partners from other major companies using .NET and beyond.

Features often go through years of public design, they get talked about in blogs, shared on social media, presentations given at conferences, and beyond. All with the ability for anyone to also engage here on GitHub or the other venues at any time.

People have been asking for and wanting this feature and it not clicking together for you doesn’t make it bad. [] is also far from just arrays, it is an existing syntax used for collection types in general, it is also used for attributes, fixed sized buffers, and more. It being used this way is not exclusive to C# either and it also happens in other C family languages and in other languages beyond.

The feature exists and it will likely become a heavily used default. You always have the option to setup an .editorconfig that allows you to opt out, but ultimately there are things that only work with the new syntax and avoiding it completely may not always be possible.

— most features are not “just another way to do the same thing”. They bring something unique to the table and address a problem scenario that can’t be solved via integration to an existing feature. Due to how languages work and how things need to be composable with other features, you can often accomplish a few of the same things using different features, but this doesn’t make them equivalent or redundant.

[ccarlo88]

C# governance is not a democracy.

Ok, now you wrote the words that for a long time I have been waiting to read. This is honest and is enough for me to accept. 😄

[HaloFour]

Ok, now you said the words that for a long time I have been waiting to read. This is honest and is enough for me to accept. 😄

That's not to say that feedback isn't considered incredibly important. Many of the proposals have started or been shaped by community feedback. Collection/dictionary literals are an example of a feature driven by community feedback, and community members were on the working group that helped to design the feature.

[jnm2]

The ability alone to write [] instead of ImmutableArray<(int A, string B, SomeOtherType C)>.Empty over and over is such a relief.

[CyrusNajmabadi]

Maybe there should be a poll (open for months, not 10 days as I have seen before) somewhere else more visible,

As Tanner mentioned, we have numerous streams of feedback, and we hear from thousands of developers, teams, groups and companies over the years on the features we work on. This has been one of the most positively received feature we've done in a very long time.

Visibility does not seem to be a problem.

Note: as we've mentioned many times in the past, it's a non-goal to please all users. Such a thing turns out to be impossible in practice as the range of customer opinions and views are just too broad (and are often contradictory with each other). As such, we aim to assess the ecosystem as a whole and produce features that in aggregate provide a ton of value to the majority of users. Unfortunately, fit this feature, you're not in that group. But that's expected that that will happen and we accept that that means a user like you may be unhappy. Just the challenge of doing and sort of work where you have millions of customers.

[CyrusNajmabadi]

Brackets are used for far more than arrays in c#. A very important correspondence here which has already shipped is list patterns, which uses brackets to already refer to a sequence of patterns to deconstruct a collection into.

Collection initializers are just the construction form of that.

[KennethHoff]

Why limit [] just to arrays? Because it feels nice? What would the alternative for a simple, all-encompassing syntax that works for all collection types be?

[huoyaoyuan]

It isn't limited to arrays. The language team has been working on supporting all collection types, including immutable collections which aren't supported by traditional collection initializer.

[KennethHoff]

I know. I was asking OP why he felt like [] should be limited to arrays - I can see the misunderstanding though.