Allow a case expression inside a pipeline

[Norlock]

Maybe it would be nice to allow case expressions directly together with pipelines. Now you always have to break up or wrap it in an extra function block, suggestion:

[0, 2, 1]
|> list.sort(int.compare)
|> case list.first {
  Ok(0) -> "0"
  Ok(1) -> "1"
  Ok(2) -> "2"
  _any -> "none"
}
|> string.append(" - number")

It would skip the case keyword and immediately use a function. You can also use function identity
to use a case without some other function, but maybe with a catchier name, like pipe.value.

[0, 2, 1]
|> list.sort(int.compare)
|> case pipe.value {
  Ok(0) -> "0"
  Ok(1) -> "1"
  Ok(2) -> "2"
  _any -> "none"
}
|> string.append(" - number")

[GearsDatapacks]

You can already do this today:

[0, 2, 1]
|> list.sort(int.compare)
|> fn(value) {
     case value {
       0 -> "0"
       1 -> "1"
       2 -> "2"
     }
   }
|> string.append(" - number")

Although personally, at this point I would either split up the pipeline into several parts, or extract the case expression into a named function, and use that in the pipeline instead.

(Note: this code doesn't actually compile, but neither would your example)

[Norlock]

I know I can do this, but I think I think its more ergonomic without the extra function block, noted I will fix the example function.

[GearsDatapacks]

Gleam isn't about being ergonomic. This change doesn't give us any new functionality, and adds a second way of doing something you can already do.
If the only reason to add this is for brevity, it's unlikely this will be added.

[Norlock]

Yes but the every other pipeline expression also works with fn (...) { ... }. The reason you don't have to do it, is also only done for ergonomics, so why not with case expressions?

[GearsDatapacks]

I'm not really sure what you mean by that. There is only 1 kind of expression that you can use in pipelines: functions. Anything else must be put inside an anonymous function.

[lpil]

This doesn't solve any particular problem today and it adds a second way to do something, so it is unlikely to be accepted. There needs to be clear value for any new features as keeping the language small with little to no changes it a goal of ours.

[Norlock]

Ok makes sense. If there is no interest I will close this.