[B] Merge pull request ocaml#1778 from voodoos/find-command-opt

Add a `find_command_opt` alternative to `find_command` that does not raise

CHANGES.md

@@ -6,6 +6,8 @@ unreleased
     - Addition of a `merlin-lib.commands` library which disassociates the
       execution of commands from the `new_protocol`, from the binary, allowing
       it to be invoked from other projects (#1758)
+    - `merlin-lib.commands`: Add a `find_command_opt` alternative to
+      `find_command` that does not raise (#1778)
 
 merlin 4.15
 ===========

src/commands/new_commands.ml

@@ -81,12 +81,11 @@ let marg_completion_kind f = Marg.param "completion-kind"
           str
     )
 
-let rec find_command name = function
-  | [] -> raise Not_found
-  | (Command (name', _, _, _, _) as command) :: xs ->
-    if name = name' then
-      command
-    else find_command name xs
+let command_is ~name (Command (name', _, _, _, _)) = String.equal name name'
+
+let find_command name = List.find ~f:(command_is ~name)
+
+let find_command_opt name = List.find_opt ~f:(command_is ~name)
 
 let run pipeline query =
   Logger.log ~section:"New_commands" ~title:"run(query)"
@@ -236,9 +235,9 @@ Otherwise, Merlin looks for the documentation for the entity under the cursor (a
     ]
     ~default: `None
     begin fun buffer pos ->
-      match pos with 
+      match pos with
       | `None -> failwith "-position <pos> is mandatory"
-      | #Msource.position as pos -> 
+      | #Msource.position as pos ->
         run buffer (Query_protocol.Syntax_document pos)
     end
   ;

src/commands/new_commands.mli

@@ -35,4 +35,10 @@ type command =
 
 val all_commands : command list
 
+(** [find_command name cmds] returns the command with name [name] in the list
+    [cmds] if it exists. Raises [Not_found] if it does not. *)
 val find_command : string -> command list -> command
+
+(** [find_command name cmds] optionaly returns the command with name [name] if
+    it is in the list [cmds]. *)
+val find_command_opt : string -> command list -> command option