Source file query.ml

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     This file is part of Merlin, an helper for ocaml editors

     Copyright (C) 2013 - 2024  Xavier Van de Woestyne <xaviervdw(_)gmail.com>
                                Arthur Wendling <arthur(_)tarides.com>


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type t = { words : string list; type_expr : Type_expr.t option }

let equal { words = words_a; type_expr = type_expr_a }
    { words = words_b; type_expr = type_expr_b } =
  List.equal String.equal words_a words_b
  && Option.equal Type_expr.equal type_expr_a type_expr_b

let to_string { words; type_expr } =
  let words = String.concat "; " words in
  let type_expr =
    type_expr
    |> Option.map Type_expr.to_string
    |> Option.value ~default:"<no type-query>"
  in
  "[" ^ words ^ "] " ^ type_expr

let balance_parens len str =
  let rec aux i open_parens close_parens =
    if i >= len then (open_parens, close_parens)
    else
      match str.[i] with
      | '(' -> aux (succ i) (succ open_parens) close_parens
      | ')' when open_parens > 0 -> aux (succ i) (pred open_parens) close_parens
      | ')' -> aux (succ i) open_parens (succ close_parens)
      | _ -> aux (succ i) open_parens close_parens
  in
  let o, c = aux 0 0 0 in
  let o = String.make c '(' and c = String.make o ')' in
  o ^ str ^ c

let naive_of_string str =
  str |> String.split_on_char ' '
  |> List.filter (fun s -> not (String.equal s String.empty))

let guess_type_search len str =
  len >= 1
  && (Char.equal str.[0] '\''
     || String.contains str '-' || String.contains str '(')

let from_string str =
  let len = String.length str in
  let words, type_expr =
    match String.index_opt str ':' with
    | None ->
      if guess_type_search len str then
        let str = balance_parens len str in
        ("", Type_expr.from_string str)
      else (str, None)
    | Some loc ->
      let str_name = String.sub str 0 loc
      and str_type = String.sub str (succ loc) (len - loc - 1) in
      let len = String.length str_type in
      let str_type = balance_parens len str_type in
      (str_name, Type_expr.from_string str_type)
  in
  let words = naive_of_string words in
  { words; type_expr }

let distance_for { words; type_expr } ~path candidate =
  let type_cost =
    type_expr
    |> Option.map (fun query -> Type_distance.compute ~query ~entry:candidate)
    |> Option.value ~default:0
  in
  let name_cost = Name_cost.best_distance words path in
  name_cost + type_cost