Add support for parsing implicit fun with ?MODULE (#1509)

Also add support for parsing variables in implicit funs.
erlang-ls · Apr 30, 2024 · acea603 · acea603
1 parent 908d9e8
commit acea603
Show file tree

Hide file tree

Showing 3 changed files with 96 additions and 4 deletions.
diff --git a/apps/els_lsp/src/els_implementation_provider.erl b/apps/els_lsp/src/els_implementation_provider.erl
@@ -46,11 +46,14 @@ find_implementation(Document, Line, Character) ->
 implementation(
     Document,
     #{
-        kind := application,
+        kind := Kind,
         id := {_M, F, A},
         data := #{mod_is_variable := true}
     } = POI
-) ->
+) when
+    Kind =:= application;
+    Kind =:= implicit_fun
+->
     %% Try to handle Mod:function() by assuming it is a behaviour callback.
     implementation(Document, POI#{kind => callback, id => {F, A}});
 implementation(Document, #{kind := application, id := MFA}) ->

diff --git a/apps/els_lsp/src/els_parser.erl b/apps/els_lsp/src/els_parser.erl
@@ -831,9 +831,36 @@ implicit_fun(Tree) ->
             throw:syntax_error ->
                 undefined
         end,
+
     case FunSpec of
         undefined ->
-            [];
+            NameTree = erl_syntax:implicit_fun_name(Tree),
+            case try_analyze_implicit_fun(Tree) of
+                {{ModType, Mod}, {FunType, Function}, Arity} ->
+                    ModTree = erl_syntax:module_qualifier_argument(NameTree),
+                    FunTree = erl_syntax:arity_qualifier_body(
+                        erl_syntax:module_qualifier_body(NameTree)
+                    ),
+                    Data = #{
+                        name_range => els_range:range(erl_syntax:get_pos(FunTree)),
+                        mod_range => els_range:range(erl_syntax:get_pos(ModTree)),
+                        mod_is_variable => ModType =:= variable,
+                        fun_is_variable => FunType =:= variable
+                    },
+                    [poi(erl_syntax:get_pos(Tree), implicit_fun, {Mod, Function, Arity}, Data)];
+                {Function, Arity} ->
+                    ModTree = erl_syntax:module_qualifier_argument(NameTree),
+                    FunTree = erl_syntax:arity_qualifier_body(
+                        erl_syntax:module_qualifier_body(NameTree)
+                    ),
+                    Data = #{
+                        name_range => els_range:range(erl_syntax:get_pos(FunTree)),
+                        mod_range => els_range:range(erl_syntax:get_pos(ModTree))
+                    },
+                    [poi(erl_syntax:get_pos(Tree), implicit_fun, {Function, Arity}, Data)];
+                _ ->
+                    []
+            end;
         _ ->
             NameTree = erl_syntax:implicit_fun_name(Tree),
             Data =
@@ -854,6 +881,44 @@ implicit_fun(Tree) ->
             [poi(erl_syntax:get_pos(Tree), implicit_fun, FunSpec, Data)]
     end.
 
+-spec try_analyze_implicit_fun(tree()) ->
+    {{atom(), atom()}, {atom(), atom()}, arity()}
+    | {atom(), arity()}
+    | undefined.
+try_analyze_implicit_fun(Tree) ->
+    FunName = erl_syntax:implicit_fun_name(Tree),
+    ModQBody = erl_syntax:module_qualifier_body(FunName),
+    ModQArg = erl_syntax:module_qualifier_argument(FunName),
+    case erl_syntax:type(ModQBody) of
+        arity_qualifier ->
+            AqBody = erl_syntax:arity_qualifier_body(ModQBody),
+            AqArg = erl_syntax:arity_qualifier_argument(ModQBody),
+            case {erl_syntax:type(ModQArg), erl_syntax:type(AqBody), erl_syntax:type(AqArg)} of
+                {macro, atom, integer} ->
+                    M = erl_syntax:variable_name(erl_syntax:macro_name(ModQArg)),
+                    F = erl_syntax:atom_value(AqBody),
+                    A = erl_syntax:integer_value(AqArg),
+                    case M of
+                        'MODULE' ->
+                            {F, A};
+                        _ ->
+                            undefined
+                    end;
+                {ModType, FunType, integer} when
+                    ModType =:= variable orelse ModType =:= atom,
+                    FunType =:= variable orelse FunType =:= atom
+                ->
+                    M = node_name(ModQArg),
+                    F = node_name(AqBody),
+                    A = erl_syntax:integer_value(AqArg),
+                    {{ModType, M}, {FunType, F}, A};
+                _Types ->
+                    undefined
+            end;
+        _Type ->
+            undefined
+    end.
+
 -spec macro(tree()) -> [els_poi:poi()].
 macro(Tree) ->
     Anno = macro_location(Tree),

diff --git a/apps/els_lsp/test/els_parser_SUITE.erl b/apps/els_lsp/test/els_parser_SUITE.erl
@@ -39,7 +39,8 @@
     unicode_clause_pattern/1,
     latin1_source_code/1,
     record_comment/1,
-    pragma_noformat/1
+    pragma_noformat/1,
+    implicit_fun/1
 ]).
 
 %%==============================================================================
@@ -539,6 +540,29 @@ pragma_noformat(_Config) ->
     ?assertMatch({ok, _}, els_parser:parse(Text)),
     ?assertMatch({ok, _}, els_parser:parse_text(Text)).
 
+implicit_fun(_Config) ->
+    ?assertMatch(
+        [#{id := {foo, 0}}],
+        parse_find_pois(<<"fun foo/0">>, implicit_fun)
+    ),
+    ?assertMatch(
+        [#{id := {foo, foo, 0}}],
+        parse_find_pois(<<"fun foo:foo/0">>, implicit_fun)
+    ),
+    ?assertMatch(
+        [#{id := {'Var', foo, 0}, data := #{mod_is_variable := true}}],
+        parse_find_pois(<<"fun Var:foo/0">>, implicit_fun)
+    ),
+    ?assertMatch(
+        [#{id := {foo, 'Var', 0}, data := #{fun_is_variable := true}}],
+        parse_find_pois(<<"fun foo:Var/0">>, implicit_fun)
+    ),
+    ?assertMatch(
+        [#{id := {foo, 0}}],
+        parse_find_pois(<<"fun ?MODULE:foo/0">>, implicit_fun)
+    ),
+    ok.
+
 %%==============================================================================
 %% Helper functions
 %%==============================================================================