I'd like to propose extending the API for Keyword and Map, fetch! method:
Map.fetch!(%{a: 1}, :b, 2) => 2
Keyword.fetch!([a: 1], :b, 2) => 2
Third argument represents value which will be returned in case the
requested key is missing. Optionally maybe it could also accept the
function which is
Looks like get does not evaluate the fallback function:
Keyword.get([{:a, 1}], :b, fn () -> 2 + 2 end) => #Function<45.97283095/0
in :erl_eval.expr/5>
Maybe fetch!/3 could work like that?
Keyword.fetch!([{:a, 1}], :b, fn () -> 2 + 2 end) => 4
On Tuesday, January 26, 2021 at 9:40:13 AM UTC+1
Hello,
There is Map.get/3 already, how would this differ?
Best
Adam
On Tue, 26 Jan 2021 at 08:38, Paweł Urbanek
wrote:
>
> I'd like to propose extending the API for Keyword and Map, fetch! method:
>
> Map.fetch!(%{a: 1}, :b, 2) => 2
> Keyword.fetch!([a: 1], :b, 2) => 2
>
> Third argument
Hello,
I think you're looking for `.get_lazy/3` functions.
Best regards,
Jean
Le mardi 26 janvier 2021 à 00:47 -0800, Paweł Urbanek a écrit :
> Looks like get does not evaluate the fallback function:
>
> Keyword.get([{:a, 1}], :b, fn () -> 2 + 2 end) =>
> #Function<45.97283095/0 in
Thanks, I was not aware of that.
On Tuesday, January 26, 2021 at 9:48:23 AM UTC+1 jean.pa...@gmail.com wrote:
> Hello,
> I think you're looking for `.get_lazy/3` functions.
>
> Best regards,
> Jean
>
>
> Le mardi 26 janvier 2021 à 00:47 -0800, Paweł Urbanek a écrit :
>
> Looks like get does not
+1 for the proposal
+1 for including package version/additional options in cache location
I often find myself wanting to demonstrate a pattern or debug something
outside of the context of whatever full application I'm currently working
on, so this would be super useful. I like low-friction, so
PR: https://github.com/elixir-lang/elixir/pull/10674
poniedziałek, 25 stycznia 2021 o 13:11:03 UTC+1 woj...@wojtekmach.pl
napisał(a):
> On 25 Jan 2021, at 11:40, Boris Kuznetsov wrote:
>
> Recompilation (and delay) on every new run seems like a major issue.
>
> Probably, if you call
One potential benefit to a Map.fetch/3 command that wasn't considered is
that it could help users define more specific error types. There's a
loose convention to use {:ok, val} | :error | {:error, reason} as a
"result" type in Elixir (analogous to Rust's Option and Result or
Haskell's Maybe
This can be accomplished by using a `with` in which the `else` clause is the
good result. Readability is up for debate of course.
with :error <- Map.fetch(states, abbreviation), do: {:error, "State not found"}
-Greg Vaughn
> On Jan 26, 2021, at 3:50 PM, Jonathan Arnett wrote:
>
> One
