js_dump_property.ml

(* Copyright (C) 2017 Authors of BuckleScript
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * In addition to the permissions granted to you by the LGPL, you may combine
 * or link a "work that uses the Library" with a publicly distributed version
 * of this file to produce a combined library or application, then distribute
 * that combined work under the terms of your choosing, with no requirement
 * to comply with the obligations normally placed on you by section 4 of the
 * LGPL version 3 (or the corresponding section of a later version of the LGPL
 * should you choose to use a later version).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)


module P = Ext_pp
module L = Js_dump_lit 

(**
   https://stackoverflow.com/questions/9367572/rules-for-unquoted-javascript-object-literal-keys
   https://mathiasbynens.be/notes/javascript-properties
   https://mathiasbynens.be/notes/javascript-identifiers

   Let's not do smart things
   {[
     { 003 : 1} 
   ]}
   becomes 
   {[
     { 3 : 1}
   ]}
*)

let obj_property_no_need_quot s = 
  let len = String.length s in 
  if len > 0 then 
    match String.unsafe_get s 0 with 
    | '$' | '_'
    | 'a'..'z'| 'A' .. 'Z' ->
      Ext_string.for_all_from  s
        1 
        (function 
          | 'a'..'z'|'A'..'Z'
          | '$' | '_' 
          | '0' .. '9' -> true
          | _ -> false)

    | _ -> false
  else 
    false 
(** used in printing keys 
    {[
      {"x" : x};;
      {x : x }
        {"50x" : 2 } GPR #1943
]}
    Note we can not treat it in the same way when printing
    [x.id] vs [{id : xx}]
    for example, id can be number in object literal
*)

(** used in property access 
    {[
      f.x ;;
      f["x"];;
    ]}
*)
let property_access f s = 
  if obj_property_no_need_quot s then 
    begin 
      P.string f L.dot;
      P.string f s; 
    end
  else
    begin 
      P.bracket_group f 1 (fun _ ->
      (* avoid cases like 
        "0123", "123_456"
      *)
      match string_of_int (int_of_string s ) with 
      | s0 when s0 = s -> 
        P.string f s 
      | _  ->
        Js_dump_string.pp_string f s
      | exception _ -> 
        Js_dump_string.pp_string f s
    )
    end

let property_key f (s : J.property_name) =     
  match s with 
  | Lit s ->
    if obj_property_no_need_quot s then 
      P.string f s 
    else Js_dump_string.pp_string f s  
 | Symbol_name -> 
    P.string f 
       {|[Symbol.for("name")]|}