Type search custom request

.github/workflows/build-and-test.yml

@@ -53,8 +53,8 @@ jobs:
           allow-prerelease-opam: true
 
       # Remove this pin once a compatible version of Merlin has been released
-      # - name: Pin dev Merlin
-      #   run: opam pin https://github.com/ocaml/merlin.git#master
+      - name: Pin dev Merlin
+        run: opam pin https://github.com/ocaml/merlin.git#main
 
       - name: Build and install dependencies
         run: opam install .

CHANGES.md

@@ -15,6 +15,9 @@
 
 - Add a code-action for syntactic and semantic movement shortcuts based on Merlin's Jump command (#1364)
 
+- Add custom
+  [`ocamllsp/typeSearch`](/ocaml-lsp-server/docs/ocamllsp/typeSearch-spec.md) request (#1369)
+
 ## Fixes
 
 - Kill unnecessary ocamlformat processes with sigterm rather than sigint or

ocaml-lsp-server/docs/ocamllsp/typeSearch-spec.md

@@ -0,0 +1,52 @@
+# TypeSearch Request
+
+## Description
+
+This custom request allows clients to perform a type search at a specific position within a text document based on finding functions or types that match a specific query pattern.
+
+## Server capability
+
+- property name: `handleTypeSearch`
+- property type: `boolean`
+
+## Request
+
+```js
+export interface TypeSearchParams extends TexDocumentPositionParams
+{
+    query: string;
+    limit: int;
+    with_doc: bool;
+}
+```
+- method: `ocamllsp/typeSearch`
+- params:
+    - `TextDocumentPositionParams`: This is an existing interface that includes:
+            - `TextDocumentIdentifier`: Specifies the document uri for which the request is sent.
+            - `Position`: Specifies the cursor position.
+        More details can be found in the [TextDocumentPositionParams - LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocumentPositionParams).
+    - `query`: The search pattern.
+    - `limit`: The number of results to return
+    - `with_doc`: If to return documentation information or not
+
+## Response
+
+```js
+result: TypeSearch | null
+export interface TypeSearch {
+    type t = Query_protocol.type_search_result list
+}
+```
+- `t`: A list of types that match the query.
+    ```
+    type Query_protocol.type_search_result =
+    {
+        name : string; // The fully qualified name of this result.
+        typ : string;  // The signature of this result.
+        loc : Range.t; // The location of the definition of this result in the source code.
+        doc : string option; // Optional documentation associated with this result.
+        cost : int; // A numeric value representing the "cost" or distance between this result and the query.
+        constructible : string; // A constructible form or template that can be used to invoke this result
+    }
+    ```
+- A response with null result is returned if no entries are found.

ocaml-lsp-server/src/custom_requests/custom_request.ml

@@ -6,3 +6,4 @@ module Typed_holes = Req_typed_holes
 module Type_enclosing = Req_type_enclosing
 module Wrapping_ast_node = Req_wrapping_ast_node
 module Get_documentation = Req_get_documentation
+module Type_search = Req_type_search

ocaml-lsp-server/src/custom_requests/custom_request.mli

@@ -8,3 +8,4 @@ module Typed_holes = Req_typed_holes
 module Type_enclosing = Req_type_enclosing
 module Wrapping_ast_node = Req_wrapping_ast_node
 module Get_documentation = Req_get_documentation
+module Type_search = Req_type_search

ocaml-lsp-server/src/custom_requests/req_type_search.ml

@@ -0,0 +1,92 @@
+open Import
+module TextDocumentPositionParams = Lsp.Types.TextDocumentPositionParams
+
+let meth = "ocamllsp/typeSearch"
+let capability = "handleTypeSearch", `Bool true
+
+module TypeSearchParams = struct
+  type t =
+    { text_document : TextDocumentIdentifier.t
+    ; position : Position.t
+    ; limit : int
+    ; query : string
+    ; with_doc : bool
+    }
+
+  let t_of_yojson json =
+    let open Yojson.Safe.Util in
+    let textDocumentPosition = Lsp.Types.TextDocumentPositionParams.t_of_yojson json in
+    let query = json |> member "query" |> to_string in
+    let limit = json |> member "limit" |> to_int in
+    let with_doc = json |> member "with_doc" |> to_bool in
+    { position = textDocumentPosition.position
+    ; text_document = textDocumentPosition.textDocument
+    ; query
+    ; limit
+    ; with_doc
+    }
+  ;;
+
+  let yojson_of_t { text_document; position; query; limit; with_doc } =
+    `Assoc
+      (("textDocument", TextDocumentIdentifier.yojson_of_t text_document)
+       :: ("position", Position.yojson_of_t position)
+       :: ("limit", `Int limit)
+       :: ("with_doc", `Bool with_doc)
+       :: [ "query", `String query ])
+  ;;
+end
+
+module TypeSearch = struct
+  type t = string Query_protocol.type_search_result list
+
+  let yojson_of_t (t : t) =
+    let yojson_of_type_search_result (res : string Query_protocol.type_search_result) =
+      `Assoc
+        [ "name", `String res.name
+        ; "typ", `String res.typ
+        ; "loc", Range.yojson_of_t (Range.of_loc res.loc)
+        ; ( "doc"
+          , match res.doc with
+            | Some d -> `String d
+            | None -> `Null )
+        ; "cost", `Int res.cost
+        ; "constructible", `String res.constructible
+        ]
+    in
+    `List (List.map ~f:yojson_of_type_search_result t)
+  ;;
+end
+
+type t = TypeSearch.t
+
+module Request_params = struct
+  type t = TypeSearchParams.t
+
+  let yojson_of_t t = TypeSearchParams.yojson_of_t t
+
+  let create text_document position limit query with_doc : t =
+    { text_document; position; limit; query; with_doc }
+  ;;
+end
+
+let dispatch merlin position limit query with_doc =
+  Document.Merlin.with_pipeline_exn merlin (fun pipeline ->
+    let position = Position.logical position in
+    let query = Query_protocol.Type_search (query, position, limit, with_doc) in
+    let results = Query_commands.dispatch pipeline query in
+    TypeSearch.yojson_of_t results)
+;;
+
+let on_request ~params state =
+  Fiber.of_thunk (fun () ->
+    let params = (Option.value ~default:(`Assoc []) params :> Yojson.Safe.t) in
+    let TypeSearchParams.{ text_document; position; limit; query; with_doc } =
+      TypeSearchParams.t_of_yojson params
+    in
+    let uri = text_document.uri in
+    let doc = Document_store.get state.State.store uri in
+    match Document.kind doc with
+    | `Other -> Fiber.return `Null
+    | `Merlin merlin -> dispatch merlin position limit query with_doc)
+;;

ocaml-lsp-server/src/custom_requests/req_type_search.mli

@@ -0,0 +1,14 @@
+open Import
+
+module Request_params : sig
+  type t
+
+  val yojson_of_t : t -> Json.t
+  val create : TextDocumentIdentifier.t -> Position.t -> int -> string -> bool -> t
+end
+
+type t
+
+val meth : string
+val capability : string * [> `Bool of bool ]
+val on_request : params:Jsonrpc.Structured.t option -> State.t -> Json.t Fiber.t

ocaml-lsp-server/src/ocaml_lsp_server.ml

@@ -539,6 +539,7 @@ let on_request
        ; Req_type_enclosing.meth, Req_type_enclosing.on_request
        ; Req_get_documentation.meth, Req_get_documentation.on_request
        ; Req_wrapping_ast_node.meth, Req_wrapping_ast_node.on_request
+       ; Req_type_search.meth, Req_type_search.on_request
        ; ( Semantic_highlighting.Debug.meth_request_full
          , Semantic_highlighting.Debug.on_request_full )
        ; ( Req_hover_extended.meth

ocaml-lsp-server/test/e2e-new/dune

@@ -62,6 +62,7 @@
     test
     type_enclosing
     documentation
+    type_search
     with_pp
     with_ppx
     workspace_change_config))))