Driver: include occurrences count in the search index

Signed-off-by: Paul-Elliot <peada@free.fr>

Author: panglesd

doc/driver.mld

@@ -783,7 +783,7 @@ Some more details about the json format:
 Search engines written in OCaml can also call the [Odoc_model.Fold.unit] and  [Odoc_model.Fold.page] function, in conjunction with [Odoc_search.Entry.entry_of_item] in order to get an OCaml value of each element to be indexed.
 
 {[
-let index_generate ?(ignore_output = false) () =
+let index_generate ?(ignore_output = false) occurrence_file =
   let open Cmd in
   let files =
     OS.Dir.contents (Fpath.v ".")
@@ -796,7 +796,7 @@ let index_generate ?(ignore_output = false) () =
   let index_map = Fpath.v "index.map" in
   let () = Bos.OS.File.write_lines index_map files |> get_ok in
   let cmd =
-    odoc % "compile-index" % "-o" % "html/index.json" % "--file-list"
+    odoc % "compile-index" % "-o" % "html/index.json" % "--occurrences" % p occurrence_file % "--file-list"
     % p index_map
   in
   let lines = run cmd in
@@ -855,7 +855,9 @@ The following code executes all of the above, and we're done!
 {[
 let compiled = compile_all () in
 let linked = link_all compiled in
-let () = index_generate () in
+let occurrence_file = Fpath.v "occurrences-odoc_and_deps.odoc" in
+let _ = count_occurrences occurrence_file in
+let () = index_generate occurrence_file in
 let _ = js_index () in
 let _ = count_occurrences (Fpath.v "occurrences-from-odoc.odoc") in
 generate_all linked

src/occurrences/table.ml

@@ -76,7 +76,7 @@ let rec get t id =
   | `SourcePage _ | `Page _ | `LeafPage _ | `CoreType _ | `SourceLocation _
   | `CoreException _ | `Label _ | `SourceLocationMod _ | `Result _
   | `AssetFile _ | `SourceDir _ | `SourceLocationInternal _ ->
-      assert false
+      None
 
 let rec iter f tbl =
   H.iter