hphp/hack/src/server/ffpAutocompleteService.ml

   1 (**
   2  * Copyright (c) 2017, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under the MIT license found in the
   6  * LICENSE file in the "hack" directory of this source tree.
   7  *
   8 *)
   9
  10 module PositionedSyntax = Full_fidelity_positioned_syntax
  11 module SourceText = Full_fidelity_source_text
  12 module SyntaxKind = Full_fidelity_syntax_kind
  13 module SyntaxTree = Full_fidelity_syntax_tree.WithSyntax(PositionedSyntax)
  14 module TokenKind = Full_fidelity_token_kind
  15
  16 open Core_kernel
  17 open AutocompleteTypes
  18
  19 let empty_autocomplete_token = "PLACEHOLDER"
  20
  21 let make_keyword_completion (replace_pos:Ide_api_types.range) (keyword_name:string) =
  22   {
  23     res_pos = Pos.none |> Pos.to_absolute;
  24     res_replace_pos = replace_pos;
  25     res_base_class = None;
  26     res_ty = "keyword";
  27     res_name = keyword_name;
  28     res_kind = Keyword_kind;
  29     func_details = None;
  30   }
  31
  32 let handle_empty_autocomplete (pos: File_content.position) file_content =
  33   let open File_content in
  34   let offset = File_content.get_offset file_content pos in
  35   let prev_char = File_content.get_char file_content (offset-1) in
  36   let next_char = File_content.get_char file_content offset in
  37   let is_whitespace = function ' ' | '\n' | '\r' | '\t' -> true | _ -> false in
  38   if is_whitespace prev_char && is_whitespace next_char then
  39     let edits = [{range = Some {st = pos; ed = pos}; text = empty_autocomplete_token}] in
  40     File_content.edit_file_unsafe file_content edits
  41   else
  42     file_content
  43
  44 let auto_complete
  45   (tcopt:TypecheckerOptions.t)
  46   (file_content:string)
  47   (pos:File_content.position)
  48   ~(basic_only:bool)
  49   ~(filter_by_token:bool) : result =
  50   let open File_content in
  51   (* The part of the line from the far left end to the point where the caret is. *)
  52   let new_file_content = handle_empty_autocomplete pos file_content in
  53   let dummy_path = Relative_path.(create Dummy "<autocomplete>") in
  54   let source_text = SourceText.make dummy_path new_file_content in
  55   let offset = SourceText.position_to_offset source_text (pos.line, pos.column) in
  56   let syntax_tree = SyntaxTree.make source_text in
  57   let positioned_tree = SyntaxTree.root syntax_tree in
  58   let replace_pos =
  59     let syntax = List.hd_exn (PositionedSyntax.parentage positioned_tree offset) in
  60     let (start_line, start_col) =
  61       SourceText.offset_to_position source_text (PositionedSyntax.start_offset syntax)
  62     in
  63     let (end_line, end_col) =
  64       SourceText.offset_to_position source_text (PositionedSyntax.end_offset syntax)
  65     in
  66     {
  67       Ide_api_types.st = {
  68         Ide_api_types.line = start_line;
  69         column = start_col;
  70       };
  71       ed = {
  72         Ide_api_types.line = end_line;
  73         column = end_col;
  74       }
  75     }
  76   in
  77
  78   let (context, stub) = FfpAutocompleteContextParser.get_context_and_stub positioned_tree offset in
  79   (* If we are running a test, filter the keywords and local variables based on
  80   the token we are completing. *)
  81   let stub = if file_content <> new_file_content then
  82       String_utils.rstrip stub empty_autocomplete_token
  83     else
  84       stub
  85   in
  86   let filter_results res = List.filter res ~f:begin fun res ->
  87     if filter_by_token
  88     then String_utils.string_starts_with res.res_name stub
  89     else true
  90   end in
  91   (* Delegate to each type of completion to determine whether or not that
  92      type is valid in the current context *)
  93   let keyword_completions =
  94     FfpAutocompleteKeywords.autocomplete_keyword context
  95     |> List.map ~f:(make_keyword_completion replace_pos)
  96   in
  97   let type_based_completions =
  98     FfpAutocompleteTypeCheck.run ~context ~file_content ~stub ~pos ~tcopt ~basic_only
  99   in
 100   let global_completions =
 101     FfpAutocompleteGlobals.get_globals context stub positioned_tree replace_pos
 102   in
 103   [keyword_completions; type_based_completions; global_completions]
 104   |> List.concat_no_order
 105   |> filter_results
 106   |> List.sort ~compare:(fun a b -> compare a.res_name b.res_name)
 107   |> List.remove_consecutive_duplicates ~equal:(fun a b -> a.res_name = b.res_name)