north finch
What is the best way to map a list and then call a function that potentially errors from within?
e.g.
try mentions =
map
|> get_field_safe(
dyn_atom("mentions"),
dynamic.list(dynamic.map(dynamic.dynamic, dynamic.dynamic)),
)
|> list.map(fn(user_map) {
try user_cast = user_map
|> user.from_map
user_cast
})
dim crag
so you have a List(a), and you have a function fn(a) -> Result(b, error), and you want to try the whole thing and error if any of the items become Error?
north finch
so you have a `List(a)`, and you have a function `fn(a) -> Result(b, error)`, an...
yes!
dim crag
Combines a list of results into a single result. If all elements in the list are Ok then returns an Ok holding the list of values. If any element is Error then returns the first error.
try mentions =
map
|> get_field_safe(...)
|> list.map(...)
|> result.all
so the list.map should return Result(User, MyError) and then i use result.all to get either Ok(List(User)) or Error(MyError)
dim crag
yeah
rough saddle
U mean… list.try_map?
dim crag
of course that's a thing
rough saddle
Lmao
dim crag
list module is so bloated i swear 😂
rough saddle
Git gud
Tbh that one I don’t mind cause I use it all the damn time
It’s more performant that a map and all cause it exits early if there’s an error
dim crag
U mean… list.try_map?
actually i mean sequence :: (Traversable t, Monad m) => t (m a) -> m (t a) 🙄
north finch
U mean… list.try_map?
thats a thing?
rough saddle
Yes lol
north finch
xD thanks yeah that worked
eternal pelican
`list` module is so bloated i swear 😂
A wild Elm programmer appears. I swear Gleam has a small list module compared to every language I know
rough saddle
@dim crag u know you can always just not import the stdlib 😛
dim crag
native charm
`list` module is so bloated i swear 😂
whats your ideal list module? just reduce?
dim crag
i feel attacked