Implement emitting code lenses for functions.

Author: zth

analysis/src/Cli.ml

@@ -11,7 +11,8 @@ API examples:
   ./rescript-editor-analysis.exe references src/MyFile.res 10 2
   ./rescript-editor-analysis.exe rename src/MyFile.res 10 2 foo
   ./rescript-editor-analysis.exe diagnosticSyntax src/MyFile.res
-  /rescript-editor-analysis.exe inlayHint src/MyFile.res 0 3 25
+  ./rescript-editor-analysis.exe inlayHint src/MyFile.res 0 3 25
+  ./rescript-editor-analysis.exe codeLens src/MyFile.res
 
 Dev-time examples:
   ./rescript-editor-analysis.exe dump src/MyFile.res src/MyFile2.res
@@ -70,6 +71,10 @@ Options:
 
     ./rescript-editor-analysis.exe inlayHint src/MyFile.res 0 3 25
 
+  codeLens: get all code lens entries for file src/MyFile.res
+
+    ./rescript-editor-analysis.exe codeLens src/MyFile.res
+
   test: run tests specified by special comments in file src/MyFile.res
 
     ./rescript-editor-analysis.exe test src/src/MyFile.res
@@ -98,6 +103,7 @@ let main () =
     Commands.inlayhint ~path
       ~pos:(int_of_string line_start, int_of_string line_end)
       ~maxLength ~debug:false
+  | [_; "codeLens"; path] -> Commands.codeLens ~path ~debug:false
   | [_; "codeAction"; path; line; col; currentFile] ->
     Commands.codeAction ~path
       ~pos:(int_of_string line, int_of_string col)

analysis/src/Commands.ml

@@ -32,6 +32,10 @@ let inlayhint ~path ~pos ~maxLength ~debug =
   let result = Hint.inlay ~path ~pos ~maxLength ~debug |> Protocol.array in
   print_endline result
 
+let codeLens ~path ~debug =
+  let result = Hint.codeLens ~path ~debug |> Protocol.array in
+  print_endline result
+
 let hover ~path ~pos ~currentFile ~debug =
   let result =
     match Cmt.fullFromPath ~path with
@@ -391,6 +395,9 @@ let test ~path =
             let line_end = 6 in
             print_endline ("Inlay Hint " ^ path ^ " " ^ string_of_int line_start ^ ":" ^ string_of_int line_end);
             inlayhint ~path ~pos:(line_start, line_end) ~maxLength:"25" ~debug:false)
+          | "clens" ->
+            print_endline ("Code Lens " ^ path);
+            codeLens ~path ~debug:false
           | _ -> ());
           print_newline ())
     in

analysis/src/Hint.ml

@@ -119,4 +119,58 @@ let inlay ~path ~pos ~maxLength ~debug =
                | Some value ->
                  if String.length label > value then None else Some result
                | None -> Some result)
-             | None -> None)))
+             | None -> None)))
+
+let codeLens ~path ~debug =
+  let lenses = ref [] in
+  let push loc =
+    let range = Utils.cmtLocToRange loc in
+    lenses := range :: !lenses
+  in
+  (* Code lenses are only emitted for functions right now. So look for value bindings that are functions,
+     and use the loc of the value binding itself so we can look up the full function type for our code lens. *)
+  let value_binding (iterator : Ast_iterator.iterator)
+      (vb : Parsetree.value_binding) =
+    (match vb with
+    | {
+     pvb_pat = {ppat_desc = Ppat_var _; ppat_loc};
+     pvb_expr = {pexp_desc = Pexp_fun _};
+    } ->
+      push ppat_loc
+    | _ -> ());
+    Ast_iterator.default_iterator.value_binding iterator vb
+  in
+  let iterator = {Ast_iterator.default_iterator with value_binding} in
+  (if Filename.check_suffix path ".res" then
+   let parser =
+     Res_driver.parsingEngine.parseImplementation ~forPrinter:false
+   in
+   let {Res_driver.parsetree = structure} = parser ~filename:path in
+   iterator.structure iterator structure |> ignore);
+  !lenses
+  |> List.filter_map (fun (range : Protocol.range) ->
+         match Cmt.fullFromPath ~path with
+         | None -> None
+         | Some full -> (
+           match
+             References.getLocItem ~full
+               ~pos:(range.start.line, range.start.character + 1)
+               ~debug
+           with
+           | Some {locType = Typed (_, typeExpr, _)} ->
+             Some
+               (Protocol.stringifyCodeLens
+                  {
+                    range;
+                    command =
+                      Some
+                        {
+                          (* Code lenses can run commands. An empty command string means we just want the editor
+                             to print the text, not link to running a command. *)
+                          command = "";
+                          (* Print the type with a huge line width, because the code lens always prints on a
+                             single line in the editor. *)
+                          title = typeExpr |> Shared.typeToString ~lineWidth:400;
+                        };
+                  })
+           | _ -> None))