List.singleton clarity

[tibastral]

Hello everybody,

List.singleton seems a little confusing, especially for people coming from OOP. As stated, we want to be mainstream.

Mathematically, List.unit would work as well and would be a little less confusing. Stack overflow discussion, Wikipedia

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[simonewebdesign]

To be fair, we might as well just remove it.

The implementation actually just wraps the value in [], so if the function name is confusing I don't see any point in keeping it.
Are there any use cases for it?

[simonewebdesign]

To be fair, we might as well just remove it.

The implementation actually just wraps the value in [], so if the function name is confusing I don't see any point in keeping it.
Are there any use cases for it?

[tibastral]

Yes it's useful. It allows to be point free.

[tibastral]

Yes it's useful. It allows to be point free.

[Angarsk8]

I was wondering the same today. This is current implementation of the singleton/1 function:

singleton : a -> List a
singleton value =
  [value]

IMHO something that simple should not be abstracted, but I'd like to know the reasons behind its existence, maybe we're all missing something.

[Angarsk8]

I was wondering the same today. This is current implementation of the singleton/1 function:

singleton : a -> List a
singleton value =
  [value]

IMHO something that simple should not be abstracted, but I'd like to know the reasons behind its existence, maybe we're all missing something.

[roine]

Use case

List.map List.singleton [1,2]
>> [[1], [2]]

[roine]

Use case

List.map List.singleton [1,2]
>> [[1], [2]]

[turboMaCk]

It's useful. List.singleton is actually pure implementation for List as a Applicative.

It's useful for lifting function to List context. Unluckilly andMap is missing in core and can be found only in List.Extra.

Actual questions in my opinion are:

• Does singleton make sense without andMap??
• Should List in core implement applicative style since most folks don't use it?

[turboMaCk]

It's useful. List.singleton is actually pure implementation for List as a Applicative.

It's useful for lifting function to List context. Unluckilly andMap is missing in core and can be found only in List.Extra.

Actual questions in my opinion are:

• Does singleton make sense without andMap??
• Should List in core implement applicative style since most folks don't use it?

[lukewestby]

Hey folks, this conversation belongs on elm-discuss or in slack. GitHub issues are for bugs, so as long as List.singleton works as advertised discussions about the name should be taken to the mailing list or slack.

[lukewestby]

Hey folks, this conversation belongs on elm-discuss or in slack. GitHub issues are for bugs, so as long as List.singleton works as advertised discussions about the name should be taken to the mailing list or slack.