Data commit

Task/Inverted-index/OCaml/inverted-index.ocaml

@@ -0,0 +1,81 @@
+TYPE_CONV_PATH "Inverted_index"
+
+type files = string array with sexp
+type inverted_index = (string * int list) list with sexp
+
+type t = files * inverted_index with sexp
+
+open Sexplib
+
+let data_file = "data.inv"
+let data_path = Filename.concat Filename.temp_dir_name data_file
+
+let get_inv_index() =
+  if Sys.file_exists data_path
+  then t_of_sexp(Sexp.load_sexp data_path)
+  else ([| |], [])
+
+let load_file f =
+  let ic = open_in f in
+  let n = in_channel_length ic in
+  let s = String.create n in
+  really_input ic s 0 n;
+  close_in ic;
+  (s)
+
+let array_push ar v =
+  let len = Array.length ar in
+  Array.init (succ len) (fun i ->
+    if i < len then Array.unsafe_get ar i else v), len
+
+let uniq lst =
+  let h = Hashtbl.create (List.length lst) in
+  List.iter (fun x -> Hashtbl.replace h x ()) lst;
+  Hashtbl.fold (fun x () xs -> x :: xs) h []
+
+let combine words i inv_index =
+  let h = Hashtbl.create (List.length inv_index) in
+  List.iter (fun (w, from) -> Hashtbl.replace h w from) inv_index;
+  List.iter (fun w ->
+    let from =
+      try Hashtbl.find h w
+      except Not_found -> []
+    in
+    Hashtbl.replace h w (i::from)
+  ) words;
+  Hashtbl.fold (fun w from acc -> (w, from) :: acc) h []
+
+let words_of_file in_file =
+  let str = load_file in_file in
+  let words = Str.split (Str.regexp "[ \r\n\t,;.?!:'/\034()]") str in
+  let words = uniq words in
+  (words)
+
+let index_file in_file =
+  let words = words_of_file in_file in
+  let files, inv_index = get_inv_index() in
+  let files, i = array_push files in_file in
+  let inv_index = combine words i inv_index in
+  let se = sexp_of_t (files, inv_index) in
+  Sexp.save data_path se
+
+let search_word word =
+  let files, inv_index = get_inv_index() in
+  try
+    let is_in = List.assoc word inv_index in
+    List.iter (fun i -> print_endline files.(i)) is_in
+  with Not_found ->
+    print_endline "# Not Found"
+
+let usage() =
+  Printf.printf "Usage: %s \
+    --index-file <file.txt> / \
+    --search-word <some-word>\n%!" Sys.argv.(0);
+  exit 1
+
+let () =
+  let cmd, arg = try (Sys.argv.(1), Sys.argv.(2)) with _ -> usage() in
+  match cmd, arg with
+  | "--index-file", in_file -> index_file in_file
+  | "--search-word", word -> search_word word
+  | _ -> usage()