Make atdgen -v produce constructors whose label do not contain "field_prefix"

[kit-ty-kate]

If we take the following example atd file:

type new_pull = { 
  title: string;
  ?body: string option;
  base: string;
  head: string;
} <ocaml field_prefix="new_pull_">

and want to get the "constructor" (create_new_pull function) using atdgen -v, we will get the following function:

val create_new_pull :
  new_pull_title: string ->
  ?new_pull_body: string ->
  new_pull_base: string ->
  new_pull_head: string ->
  unit -> new_pull
  (** Create a record of type {!type:new_pull}. *)

Instead i would've expected the following more concise version:

val create_new_pull :
  title: string ->
  ?body: string ->
  base: string ->
  head: string ->
  unit -> new_pull
  (** Create a record of type {!type:new_pull}. *)

I'm fairly new to atdgen so maybe i'm missing some known option or attribute to be able to get the right version that i wasn't able to find in the documentation.

---

Atdgen version: 2.16.0

[ahrrv]

It must be possible to use <ocaml_json field_prefix=...> to specify the field prefix just for the JSON generator.
You may also want to check this out:

atd/atdgen/src/ocaml.ml

Lines 132 to 143 in 7f78693

	let path_of_target (target : target) =
	match target with
	| Default -> [ "ocaml" ]
	| Biniou -> [ "ocaml_biniou"; "ocaml" ]
	| Json -> [ "ocaml_json"; "ocaml" ]
	| Melange -> [
	(* kept for backwards compatibility with BuckleScript *)
	"ocaml_bs";
	"ocaml_mel";
	"ocaml"
	]
	| Validate -> [ "ocaml_validate"; "ocaml" ]

[kit-ty-kate]

If i try to use ocaml_json i get:

Invalid or misplaced annotation <ocaml_json ... field_prefix... >

Also the documentation says ocaml_json is obsolete and i'm also not sure it is the correct intent. I want to have the field be their original names in json, but be prefixed in OCaml (except for the constructors). So basically in -t mode but not in -v or -j, if i understand roughly the different modes.

[kit-ty-kate]

Also this example i'm describing is part of an existing large atdgen codebase so the smaller the change, the better it'll be for me

[mjambon]

Also this example i'm describing is part of an existing large atdgen codebase so the smaller the change, the better it'll be for me

Could you just remove <ocaml field_prefix=...>? This feature used to be useful before type-driven field name disambiguation. We couldn't have two record types defined back-to-back in the same module if they shared some field names, so a solution was to prefix the field names with something. But now we can do this:

type a = { x : int }
type b = { x : int }

let get_x (p : a) = p.x

(* also works here: *)
let create_a () : a =
  { x = 0 }

(* this case is pretty annoying: need to annotate the anonymous function argument
   even though the type of the list argument of map is known to be 'a list' *)
let f (xs : a list) =
  List.map (fun (x : a) -> x.x) xs

[mjambon]

I'm fairly new to atdgen so maybe i'm missing some known option or attribute to be able to get the right version that i wasn't able to find in the documentation.

No, we don't have something like this.

[kit-ty-kate]

Could you just remove <ocaml field_prefix=...>?

no i don't think that's possible. The codebase is too large (ocaml-github), this would break everyone and i'm pretty sure there would be actual conflicts. Also i don't personally think disambiguated fields are nice to use in that context