Sorry, for some reason I completely overlooked that you were doing this with `use`. I would second the recommendation to avoid that approach. Since `use` is a special form, it’s likely you can’t do what you’re trying to do here anyway. The bigger issue is that it’s very unidiomatic - while it might save you one extra line of code versus an explicit macro, it’s very different from how most libraries expose this kind of functionality, and much less composable.
Ultimately though, I think you’ll be limited by the fact that `use` is a special form (IIRC, I haven’t confirmed that you _can’t_ do what you’re trying to do, but I suspect that’s the thing tripping you up). On Mon, Aug 9, 2021, at 12:42 AM, Yordis Prieto wrote: > aditya7, I dont disagree with you. > > There is always a balance between magic and verbosity. The reason I don't > mind "magic" in Elixir is that everything is explicit and macros are expanded > at compile time. So my intention is to make the code as simple as possible at > the cost of hidden complexity that I am OK with it at the moment. Everything > with balance, this is one of those cases where it is just a bag of data and > few things, the easier the better. > > In the worst case, I will end up doing a version of what you proposed, I am > trying to avoid having to import a module and having to call yet another > function at the moment. > On Monday, August 9, 2021 at 12:35:26 AM UTC-4 Yordis Prieto wrote: >> Hey Paul, >> >> I can't remove the comma from it thou, I get the following error, `use` >> macro expects 2 arguments as far as I can tell >> >> ``` >> ** (ArgumentError) invalid arguments for use, expected a compile time atom >> or alias, got: Command[[aggregate_identifier: :id]] >> (elixir 1.11.2) lib/kernel.ex:5006: anonymous fn/3 in >> Kernel."MACRO-use"/3 >> (elixir 1.11.2) lib/enum.ex:1399: Enum."-map/2-lists^map/1-0-"/2 >> (elixir 1.11.2) expanding macro: Kernel.use/2 >> ``` >> >> On Sunday, August 8, 2021 at 8:59:03 PM UTC-4 Paul Schoenfelder wrote: >>> __ >>> It looks to me like the error is due to a stray comma: `use Command, >>> [aggregate_identifier: :id] do` should be `use Command >>> [aggregate_identifier: :id] do`, which should work as you’d expect. >>> >>> As an aside, you might be interested in >>> https://github.com/bitwalker/strukt, which looks like it has a lot of >>> overlap with what you’re building (though what you are shooting for may be >>> totally different, I just see some similarities) >>> >>> Paul >>> >>> On Sun, Aug 8, 2021, at 7:54 PM, Adi wrote: >>>> I am not sure if supporting use/* is the right way forward here. The >>>> `Kernel.use/2` macro is reserved for invoking a module's `__using__/1` >>>> macro. To be honest, I don't like the fact that you're setting the module >>>> attributes and defining the `embedded_schema` in the same macro. You can >>>> easily just define the `@primary_key` in the `__using__/1` macro and >>>> explicitly define the `embedded_schema` in `CreateRecurringTransfer` >>>> itself, but that's my preference. >>>> >>>> Either way, if you have defined a `__using__/3` macro, you can always >>>> invoke it explicitly. Although I would rename it to avoid any confusion >>>> for developers reading the code in the future and potentially thinking it >>>> has something to do with `Kernel.use/2`. >>>> >>>> defmodule Command do >>>> defmacro aggregate_schema(opts \\ [], do: block) do >>>> unless Keyword.has_key?(opts, :aggregate_identifier) do >>>> raise ArgumentError, "Missing :aggregate_identifier key" >>>> end >>>> >>>> aggregate_identifier = Keyword.fetch!(opts, :aggregate_identifier) >>>> >>>> quote do >>>> use Ecto.Schema >>>> @primary_key { @aggregate_identifier_key, :binary_id, autogenerate: >>>> true } >>>> @derive Jason.Encoder >>>> embedded_schema unquote(block) >>>> end >>>> end >>>> end >>>> >>>> defmodule CreateRecurringTransfer do >>>> require Command >>>> Command.aggregate_schema [aggregate_identifier: :id] do >>>> field(:dtstart, :naive_datetime) >>>> field(:dtend, :naive_datetime) >>>> embeds_one(:amount, PositiveAmount) >>>> embeds_one(:rrule, Rrule) >>>> embeds_one(:owned_by, CustomerIdentity) >>>> embeds_one(:from_account, TransferAccount) >>>> embeds_one(:to_account, TransferAccount) >>>> end >>>> end >>>> >>>> On Sunday, 8 August 2021 at 16:15:59 UTC-4 [email protected] wrote: >>>>> I am trying to do the following, >>>>> >>>>> defmodule Command do >>>>> defmacro __using__(opts \\ [], do: block) do >>>>> unless Keyword.has_key?(opts, :aggregate_identifier) do >>>>> raise ArgumentError, "Missing :aggregate_identifier key" >>>>> end >>>>> >>>>> aggregate_identifier = Keyword.fetch!(opts, :aggregate_identifier) >>>>> >>>>> quote do >>>>> use Ecto.Schema >>>>> @primary_key { @aggregate_identifier_key, :binary_id, autogenerate: >>>>> true } >>>>> @derive Jason.Encoder >>>>> embedded_schema unquote(block) >>>>> end >>>>> end >>>>> end >>>>> >>>>> >>>>> Just so I can do something like, >>>>> >>>>> defmodule CreateRecurringTransfer do >>>>> use Command, [aggregate_identifier: :id] do >>>>> field(:dtstart, :naive_datetime) >>>>> field(:dtend, :naive_datetime) >>>>> embeds_one(:amount, PositiveAmount) >>>>> embeds_one(:rrule, Rrule) >>>>> embeds_one(:owned_by, CustomerIdentity) >>>>> embeds_one(:from_account, TransferAccount) >>>>> embeds_one(:to_account, TransferAccount) >>>>> end >>>>> end >>>>> >>>>> But I get `** (CompileError) iex:3: undefined function use/3` which I >>>>> assume what I am trying to do is not supported. >>>>> >>>>> I am curious to understand why it doesn't work (beside maybe not being >>>>> supported), and what would be the problem by trying to support it >>>> >>>> >>>> -- >>>> 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 [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/elixir-lang-core/46c25948-b96e-4982-b710-0ebeae1b5e96n%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/elixir-lang-core/46c25948-b96e-4982-b710-0ebeae1b5e96n%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 [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/9c80199c-ed64-427a-9d67-12847f9ef8efn%40googlegroups.com > > <https://groups.google.com/d/msgid/elixir-lang-core/9c80199c-ed64-427a-9d67-12847f9ef8efn%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. 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