Source file payload.ml

(*****************************************************************************)
(* Open Source License                                                       *)
(* Copyright (c) 2021 Valentin Chaboche                                      *)
(* Copyright (c) 2021 Nomadic Labs, <contact@nomadic-labs.com>               *)
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open Ppxlib
module E = Error

let rec pbt_from_attribute x =
  match x.attr_payload with
  | PStr structure -> pbt_from_structure structure
  | _ ->
      E.case_unsupported
        ~loc:x.attr_loc
        ~case:"Common.Attribute.pbt_from_payload"
        ()

and pbt_from_structure_item stri =
  match stri.pstr_desc with
  | Pstr_eval (expr, _) -> pbt_from_expression expr
  | _ ->
      E.case_unsupported
        ~loc:stri.pstr_loc
        ~case:"Common.Attribute.pbt_from_structure_item"
        ()

and pbt_from_structure structure =
  (* TODO: This function should be property based tested,
     forall structure : List.length (pbt_from_structure structure) = 1 *)
  List.map pbt_from_structure_item structure |> List.hd

and pbt_from_expression expression =
  match expression.pexp_desc with
  | Pexp_constant constant -> pbt_from_constant constant
  | _ ->
      E.case_unsupported
        ~loc:expression.pexp_loc
        ~case:"Common.Attribute.pbt_from_expression"
        ()

and pbt_from_constant = function
  | Pconst_string (str, _, _) -> str
  | _ -> E.case_unsupported ~case:"Common.Attribute.pbt_from_constant" ()