Ocaml中字符串的简单解析

而 Str 可能会做这个把戏,鲜为人知的 Genlex module char 流到令牌流中,您可以更轻松地解析这些令牌流。我认为 lsblk

let lexer = Genlex.make_lexer [ "=" ]

let test = "NAME=\"/dev/sda\" TYPE=\"disk\" MODEL=\"KINGSTON SV300S3\""
let test_stream = Stream.of_string test
let test_stream_token = lexer test_stream

let info =
  let l = ref [] in
  try
    while true do
      let kw = Stream.next test_stream_token in
      let eq = Stream.next test_stream_token in
      let v = Stream.next test_stream_token in
      let kw =
        match kw with Ident s -> s | _ -> failwith "Unrecognized pattern"
      in
      let () = match eq with Kwd "=" -> () | _ -> failwith "Expected '='" in
      let v = match v with String s -> s | _ -> failwith "Expected string" in
      l:=(kw,v)::!l
    done;
    assert false
  with Stream.Failure -> List.rev !l

基本上,主循环认为输入中包含的信息是表单项的序列 <key>="<value>" ,由 -生成lexer。

[("NAME", "/dev/sda"); ("TYPE", "disk"); ("MODEL", "KINGSTON SV300S3")]

let extract s = Scanf.sscanf s "NAME=%S TYPE=%S MODEL=%S" (fun x y z -> x, y ,z);;
;; extract {|NAME="/dev/sda" TYPE="disk" MODEL="KINGSTON SV300S3"|}

产量

(“/dev/sda”,“磁盘”,“金斯顿SV300S3”)

一如预期。

知道了:

let re = Str.regexp "NAME=\"\\(.*\\)\" TYPE=\"\\(.*\\)\" MODEL=\"\\(.*\\)\"" in
  match Str.string_match re line 0 with
  | false -> [`Null]
  | true  ->
     let name = Str.matched_group 1 line in
     let typ = Str.matched_group 2 line in
     let model = Str.matched_group 3 line in
     Printf.printf "%s, %s, %s\n" name typ model