Btw, we will also have a public API on Elixir v1.14 for expanding literals,
so the problem shall disappear altogether. However, you must be extremely
careful: this should only be used if you indeed don't use it at compile
time.
On Mon, May 9, 2022 at 7:56 PM Zach Daniel <zachary.s.dan...@gmail.com>
wrote:
> Also, I forgot to mention, it was @icecreamcohen on discord who had the
> idea that redefining alias may work (although they didn't really condone
> it), don't want to take credit for anyone elses ideas though.
> On Monday, May 9, 2022 at 1:53:50 PM UTC-4 Zach Daniel wrote:
>
>> This is something coming from a compile time optimization that Ash
>> Framework does.
>>
>> In an Ash resource there is something called a change its basically like
>> a plug but it operates on an Ash.Changeset
>>
>> So you might see something like this:
>> ```
>> # in the resource
>> actions do
>> create :create_with_employee do
>> change MyApp.CreateEmployee
>> end
>> end
>> # the change module
>> defmodule MyApp.CreateEmployee do
>> use Ash.Resource.Change
>>
>> def change(changeset, _opts, _context) do
>> Ash.Changeset.after_action(changeset, fn _changeset, result ->
>> MyApp.Employee.create!(result.stuff, ...)
>> end)
>> end
>> end
>>
>> Now, the change itself, when it comes to the resource, is simple static
>> configuration. It cannot affect the compilation of the resource nor should
>> any thing doing metaprogramming at compile time leverage the internals of
>> that change
>>
>> Something that changes do often is refer to other related resources, like
>> in this example case. So we drastically increase the surface area for
>> transitive compile time dependencies
>>
>> Because a runtime dependency in one link becomes a compile time
>> dependency when chained down the road. I.e I depend on the source resource,
>> call it Post at compile time, and Post depends on Employee now at runtime,
>> so I now depend on Employee at compile time.
>>
>> So to help people with their compile times, I've added some
>> metaprogramming magic that does the following (only in very specific places
>> for specific options) Macro.expand(node, %{env | lexical_tracker: nil}) and
>> it works, no more unnecessary dependency. however, if you do this:
>> ```
>> alias MyApp.CreateEmployee
>> create :name do
>> change CreateEmployee
>> end
>> ```
>> it yells at you for not using the alias, because I just disabled the
>> thing that would inform the compiler that the alias was used
>>
>> I don't necessarily want to add back in those unnecessary compile time
>> increases, so I'm looking for a way to detect that an alias had been used
>> in these cases, and produce a compiler warning if you didn't add warn:
>> false to the alias, that way you don't get a confusing "alias not used"
>> error, you get (well, I guess you get both) an explanation of why the alias
>> wasn't used and instructions to add warn: false to fix it.
>>
>>
>> The options I have so far:
>>
>> 1. redefine `alias` and default to `warn: false`
>> 2. redefine `alias` and track which ones have `warn: false` and print a
>> warning if its used in one of these instances, so they can add it
>> 3. if I detect that an alias is used, raise an error at compile time and
>> say that aliases aren't supported here
>> 4. get something in elixir core that allows explicit control to add
>> something to an explicit list of "used aliases"
>>
>> Looking at the code for the lexical_tracker, it could be as simple as
>> tracking a separate list of explicitly provided modules, or it could be a
>> different mode of reference, i.e `:compile` `:runtime` or `:ignore`, that
>> kind of thing.
>>
>> Also, if there is another way to accomplish the goal here I'm open to
>> suggestions.
>>
>> Thanks!
>>
> --
> You received this message because you are subscribed to the Google Groups
> "elixir-lang-core" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to elixir-lang-core+unsubscr...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/elixir-lang-core/f8e4ed44-f3a8-41cc-b82c-f6175ea461fdn%40googlegroups.com
> <https://groups.google.com/d/msgid/elixir-lang-core/f8e4ed44-f3a8-41cc-b82c-f6175ea461fdn%40googlegroups.com?utm_medium=email&utm_source=footer>
> .
>
--
You received this message because you are subscribed to the Google Groups
"elixir-lang-core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to elixir-lang-core+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4J0YOw5J4xzsZHMF4oWpj%2BNG3Thj6TjpK8zm9YMYw53MQ%40mail.gmail.com.
