Fuzzy goto (#1559)

If we don't have a precise match, try to find a close match for goto definition, e.g. if we have a(q,w,e) but only a/4 defined jump there.

Fixes #1250 .

Author: plux

apps/els_lsp/src/els_code_navigation.erl

@@ -204,11 +204,15 @@ find_in_document([Uri | Uris0], Document, Kind, Data, AlreadyVisited) ->
     Defs = [POI || #{id := Id} = POI <- POIs, Id =:= Data],
     {AllDefs, MultipleDefs} =
         case Data of
-            {_, any_arity} when Kind =:= function ->
+            {_, any_arity} when
+                Kind =:= function;
+                Kind =:= define;
+                Kind =:= type_definition
+            ->
                 %% Including defs with any arity
                 AnyArity = [
                     POI
-                 || #{id := {F, _}} = POI <- POIs, Kind =:= function, Data =:= {F, any_arity}
+                 || #{id := {F, _}} = POI <- POIs, Data =:= {F, any_arity}
                 ],
                 {AnyArity, true};
             _ ->
@@ -232,7 +236,8 @@ find_in_document([Uri | Uris0], Document, Kind, Data, AlreadyVisited) ->
             case MultipleDefs of
                 true ->
                     %% This will be the case only when the user tries to
-                    %% navigate to the definition of an atom
+                    %% navigate to the definition of an atom or a
+                    %% function/type/macro of wrong arity.
                     [{Uri, POI} || POI <- SortedDefs];
                 false ->
                     %% In the general case, we return only one def

apps/els_lsp/src/els_definition_provider.erl

@@ -28,14 +28,69 @@ handle_request({definition, Params}) ->
             IncompletePOIs = match_incomplete(Text, {Line, Character}),
             case goto_definition(Uri, IncompletePOIs) of
                 null ->
-                    els_references_provider:handle_request({references, Params});
+                    FuzzyPOIs = make_fuzzy(POIs),
+                    case goto_definition(Uri, FuzzyPOIs) of
+                        null ->
+                            els_references_provider:handle_request({references, Params});
+                        GoTo ->
+                            {response, GoTo}
+                    end;
                 GoTo ->
                     {response, GoTo}
             end;
         GoTo ->
             {response, GoTo}
     end.
 
+-spec make_fuzzy([els_poi:poi()]) -> [els_poi:poi()].
+make_fuzzy(POIs) ->
+    lists:flatmap(
+        fun
+            (#{kind := application, id := {M, F, _A}} = POI) ->
+                [
+                    POI#{id => {M, F, any_arity}, kind => application},
+                    POI#{id => {M, F, any_arity}, kind => type_application}
+                ];
+            (#{kind := type_application, id := {M, F, _A}} = POI) ->
+                [
+                    POI#{id => {M, F, any_arity}, kind => type_application},
+                    POI#{id => {M, F, any_arity}, kind => application}
+                ];
+            (#{kind := application, id := {F, _A}} = POI) ->
+                [
+                    POI#{id => {F, any_arity}, kind => application},
+                    POI#{id => {F, any_arity}, kind => type_application},
+                    POI#{id => {F, any_arity}, kind => macro},
+                    POI#{id => F, kind => macro}
+                ];
+            (#{kind := type_application, id := {F, _A}} = POI) ->
+                [
+                    POI#{id => {F, any_arity}, kind => type_application},
+                    POI#{id => {F, any_arity}, kind => application},
+                    POI#{id => {F, any_arity}, kind => macro},
+                    POI#{id => F, kind => macro}
+                ];
+            (#{kind := macro, id := {M, _A}} = POI) ->
+                [
+                    POI#{id => M},
+                    POI#{id => {M, any_arity}}
+                ];
+            (#{kind := macro, id := M} = POI) ->
+                [
+                    POI#{id => {M, any_arity}}
+                ];
+            (#{kind := atom, id := Id} = POI) ->
+                [
+                    POI#{id => {Id, any_arity}, kind => application},
+                    POI#{id => {Id, any_arity}, kind => type_application},
+                    POI#{id => Id, kind => macro}
+                ];
+            (_POI) ->
+                []
+        end,
+        POIs
+    ).
+
 -spec goto_definition(uri(), [els_poi:poi()]) -> [map()] | null.
 goto_definition(_Uri, []) ->
     null;