first draft

lib/nushell.ml

@@ -0,0 +1,82 @@
+open Parser
+
+(* Map a param name/type hint to a nushell type *)
+let nushell_type_of_param = function
+  | "FILE" | "file" | "PATH" | "path" | "DIR" | "dir" | "DIRECTORY"
+  | "FILENAME" | "PATTERNFILE" -> "path"
+  | "NUM" | "N" | "COUNT" | "NUMBER" | "int" | "INT" | "COLS" | "WIDTH"
+  | "LINES" | "DEPTH" | "depth" -> "int"
+  | _ -> "string"
+
+(* Escape a nushell string: wrap in double quotes, escape inner quotes *)
+let escape_nu s =
+  let buf = Buffer.create (String.length s + 2) in
+  String.iter (fun c ->
+    match c with
+    | '"' -> Buffer.add_string buf "\\\""
+    | '\\' -> Buffer.add_string buf "\\\\"
+    | _ -> Buffer.add_char buf c
+  ) s;
+  Buffer.contents buf
+
+(* Format a single flag for nushell extern *)
+let format_flag entry =
+  let buf = Buffer.create 64 in
+  Buffer.add_string buf "    ";
+  (* Flag name *)
+  (match entry.switch with
+   | Both (s, l) ->
+     Buffer.add_string buf (Printf.sprintf "--%s(-%c)" l s)
+   | Long l ->
+     Buffer.add_string buf (Printf.sprintf "--%s" l)
+   | Short s ->
+     Buffer.add_string buf (Printf.sprintf "-%c" s));
+  (* Type annotation *)
+  (match entry.param with
+   | Some (Mandatory name) ->
+     Buffer.add_string buf ": ";
+     Buffer.add_string buf (nushell_type_of_param name)
+   | Some (Optional name) ->
+     Buffer.add_string buf ": ";
+     Buffer.add_string buf (nushell_type_of_param name)
+   | None -> ());
+  (* Description as comment *)
+  if String.length entry.desc > 0 then begin
+    (* Pad to align comments *)
+    let current_len = Buffer.length buf in
+    let target = max (current_len + 1) 40 in
+    for _ = current_len to target - 1 do
+      Buffer.add_char buf ' '
+    done;
+    Buffer.add_string buf "# ";
+    Buffer.add_string buf entry.desc
+  end;
+  Buffer.contents buf
+
+(* Generate nushell extern definition for a command *)
+let generate_extern cmd_name result =
+  let buf = Buffer.create 1024 in
+  (* Main extern with flags *)
+  Buffer.add_string buf (Printf.sprintf "export extern \"%s\" [\n" (escape_nu cmd_name));
+  List.iter (fun entry ->
+    Buffer.add_string buf (format_flag entry);
+    Buffer.add_char buf '\n'
+  ) result.entries;
+  Buffer.add_string buf "]\n";
+  (* Subcommand externs *)
+  List.iter (fun (sc : subcommand) ->
+    Buffer.add_string buf
+      (Printf.sprintf "\nexport extern \"%s %s\" [  # %s\n]\n"
+         (escape_nu cmd_name) (escape_nu sc.name) (escape_nu sc.desc))
+  ) result.subcommands;
+  Buffer.contents buf
+
+(* Generate a complete nushell module *)
+let generate_module cmd_name result =
+  Printf.sprintf "module %s-completions {\n%s}\n"
+    cmd_name (generate_extern cmd_name result)
+
+(* Generate from manpage entries (no subcommands) *)
+let generate_extern_from_entries cmd_name entries =
+  let result = { entries; subcommands = [] } in
+  generate_extern cmd_name result