Add completion for binary type specifiers

apps/els_lsp/src/els_completion_provider.erl

@@ -44,6 +44,7 @@ trigger_characters() ->
  <<"-">>,
  <<"\"">>,
  <<"{">>,
+ <<"/">>,
  <<" ">>
  ].
 
@@ -198,6 +199,24 @@ find_completions(
  #{trigger := <<"-">>, document := Document, column := 1, line := Line}
 ) ->
  attributes(Document, Line);
+find_completions(
+ Prefix,
+ ?COMPLETION_TRIGGER_KIND_CHARACTER,
+ #{trigger := <<"/">>}
+) ->
+ Tokens = lists:reverse(els_text:tokens(Prefix)),
+ case in_binary_heuristic(Tokens) of
+ true ->
+ binary_type_specifier();
+ false ->
+ []
+ end;
+find_completions(
+ Prefix,
+ ?COMPLETION_TRIGGER_KIND_CHARACTER,
+ #{trigger := <<"-">>}
+) ->
+ binary_type_specifiers(Prefix);
 find_completions(
  _Prefix,
  ?COMPLETION_TRIGGER_KIND_CHARACTER,
@@ -308,6 +327,18 @@ find_completions(
  %% Check for "-anything"
  [{atom, _, _}, {'-', _}] ->
  attributes(Document, Line);
+ %% Check for "[...] -"
+ [{'-', _} | _] ->
+ binary_type_specifiers(Prefix);
+ %% Check for "[...] -"
+ [{'/', _} | _] ->
+ Tokens = lists:reverse(els_text:tokens(Prefix)),
+ case in_binary_heuristic(Tokens) of
+ true ->
+ binary_type_specifier();
+ false ->
+ []
+ end;
  %% Check for "-export(["
  [{'[', _}, {'(', _}, {atom, _, export}, {'-', _}] ->
  unexported_definitions(Document, function);
@@ -476,6 +507,115 @@ complete_atom(Name, Tokens, Opts) ->
  end
  end.
 
+-spec binary_type_specifiers(binary()) -> [completion_item()].
+binary_type_specifiers(Prefix) ->
+ %% in_binary_heuristic will only consider current line
+ %% TODO: make it work for multi-line binaries too.
+ Tokens = lists:reverse(els_text:tokens(Prefix)),
+ case
+ in_binary_heuristic(Tokens) andalso
+ in_binary_type_specifier(Tokens, [])
+ of
+ {true, TypeListTokens} ->
+ HasType = lists:any(
+ fun(T) ->
+ lists:member(T, binary_types())
+ end,
+ TypeListTokens
+ ),
+ HasEndianess = lists:any(
+ fun(T) ->
+ lists:member(T, binary_endianness())
+ end,
+ TypeListTokens
+ ),
+ HasSignedness = lists:any(
+ fun(T) ->
+ lists:member(T, binary_signedness())
+ end,
+ TypeListTokens
+ ),
+ HasUnit = lists:member(unit, TypeListTokens),
+ [binary_type_specifier(unit) || not HasUnit] ++
+ [binary_type_specifier(Label) || Label <- binary_types(), not HasType] ++
+ [binary_type_specifier(Label) || Label <- binary_endianness(), not HasEndianess] ++
+ [binary_type_specifier(Label) || Label <- binary_signedness(), not HasSignedness];
+ false ->
+ []
+ end.
+
+-spec in_binary_heuristic([any()]) -> boolean().
+in_binary_heuristic([{'>>', _} | _]) ->
+ false;
+in_binary_heuristic([{'<<', _} | _]) ->
+ true;
+in_binary_heuristic([_ | T]) ->
+ in_binary_heuristic(T);
+in_binary_heuristic([]) ->
+ false.
+
+-spec in_binary_type_specifier([any()], [atom()]) -> {true, [atom()]} | false.
+in_binary_type_specifier([{integer, _, _}, {':', _}, {atom, _, unit} | T], Spec) ->
+ in_binary_type_specifier(T, [unit | Spec]);
+in_binary_type_specifier([{atom, _, Atom} | T], Spec) ->
+ case lists:member(Atom, binary_type_specifiers()) of
+ true ->
+ in_binary_type_specifier(T, [Atom | Spec]);
+ false ->
+ false
+ end;
+in_binary_type_specifier([{'-', _} | T], Spec) ->
+ in_binary_type_specifier(T, Spec);
+in_binary_type_specifier([{'/', _} | _], Spec) ->
+ {true, Spec};
+in_binary_type_specifier([], _Spec) ->
+ false.
+
+-spec binary_type_specifiers() -> [atom()].
+binary_type_specifiers() ->
+ binary_types() ++ binary_signedness() ++ binary_endianness() ++ [unit].
+
+-spec binary_signedness() -> [atom()].
+binary_signedness() ->
+ [signed, unsigned].
+
+-spec binary_types() -> [atom()].
+binary_types() ->
+ [integer, float, binary, bytes, bitstring, bits, utf8, utf16, utf32].
+
+-spec binary_endianness() -> [atom()].
+binary_endianness() ->
+ [big, little, native].
+
+-spec binary_type_specifier() -> [completion_item()].
+binary_type_specifier() ->
+ Labels = binary_type_specifiers(),
+ [binary_type_specifier(Label) || Label <- Labels].
+
+-spec binary_type_specifier(atom()) -> completion_item().
+binary_type_specifier(unit) ->
+ case snippet_support() of
+ true ->
+ #{
+ label => <<"unit:N">>,
+ kind => ?COMPLETION_ITEM_KIND_TYPE_PARAM,
+ insertTextFormat => ?INSERT_TEXT_FORMAT_SNIPPET,
+ insertText => <<"unit:${1:N}">>
+ };
+ false ->
+ #{
+ label => <<"unit:">>,
+ kind => ?COMPLETION_ITEM_KIND_TYPE_PARAM,
+ insertTextFormat => ?INSERT_TEXT_FORMAT_PLAIN_TEXT
+ }
+ end;
+binary_type_specifier(Label) ->
+ #{
+ label => atom_to_binary(Label),
+ kind => ?COMPLETION_ITEM_KIND_TYPE_PARAM,
+ insertTextFormat => ?INSERT_TEXT_FORMAT_PLAIN_TEXT
+ }.
+
 -spec complete_record_field(map(), list()) -> items().
 complete_record_field(_Opts, [{atom, _, _}, {'=', _} | _]) ->
  [];