Is it possible to have Collections.IsNullEmpty()/Enumerable.IsNullOrEmpty() in framework

[shinkarmv]

With current available functions to check null/ empty collections/enumerable

we need to write some extension method or add explicit check on collection/enumerable for null and count ==0.

Also to check empty - we can apply Any method from Linq but it throws exception null.

So is it possible to have Collections.IsNullEmpty()/Enumerable.IsNullOrEmpty() in framework.

Thoughts?

[theunrepentantgeek]

This would be more properly a request for new methods in the base class library, not a change to the C# language.

However, given the strong push to detect null values and enable programmers to avoid having null show up unexpectedly, I'm not sure they would gain much traction.

While explicit handling is required, the current solutions are pretty concise:

// Using Any()
IEnumerable<Foo>? myEnumerable = ... // elided
if (myEnumerable?.Any() ?? false) 
{
    // myEnumerable has items
}

// Using Count
IList<Foo>? myList = ... // elided
if ((myList?.Count ?? 0) > 0) 
{
    // myList has items
}

// Custom Extension method 
if (myEnumerable.HasItems() > 0) 
{
    // myEnumerable has items
}

FWIW, I used the name HasItems() because true would imply that you have a sequence and it has items. An IsEmptyOrNull() method is ambiguous when it returns true - is it null, or is it an empty sequence?

[alrz]

With dotnet/csharplang#3435 you could do expr is [_, ..] ;)

However, the advantage of an extension method is that you can optimize for IList at runtime.

[shinkarmv]

@theunrepentantgeek - Thank you the response and proposed more feasible function to handle this.

So are we going to add HasItems() to Base Class Library?

Regards,
Mukesh

[theunrepentantgeek]

That would more properly be a request for the base class library repo, not for here. Log an issue over at dotnet/runtime. If they're interested, they'll likely accept a PR.

[YairHalberstadt]

@theunrepentantgeek this discussion has been moved to dotnet/runtime.

[theunrepentantgeek]

Oh! I didn't notice that. #embarrassing 😊

[NN---]

While it is convenient , there is much work defining how it should be implemented.
It is actually very easy to implement own extension method.
And there are plenty libraries who do it for instance:
https://github.com/rsdn/CodeJam/wiki/M_CodeJam_Collections_CollectionExtensions_IsNullOrEmpty__1

[danmoseley]

Good answers above in comments. Can't mark comment as answer. Marking as answered.