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How to compile a simple command line OCaml script in Javascript

I have a simple command line OCaml application that does the calculation on Sys.argv.(1)and prints the result to stdout. I can compile it in Javascript using js_of_ocaml, but this gives me a lot of errors about caml_ml_output_charhow undefined. I fixed these errors by removing printfs, so it starts, but it freezes firefox while it works.

How can I compile a simple command line OCaml script on a Javascript based web page; without saving the forked version or freezing the browser?

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2 answers

, -, , Javascript , . OCaml, OCaml Sys

(* JsHeader.ml *)
let output_buffer_ = Buffer.create 1000
let flush x=let module J = Js.Unsafe in let () = J.call 
        (J.variable "postMessage") (J.variable "self")
        [|J.inject (Js.string (Buffer.contents output_buffer_))|]
     in Buffer.clear output_buffer_

let print_string = Buffer.add_string output_buffer_
let print_char = Buffer.add_char output_buffer_
let print_newline () = print_char '\n'
let print_endline s = print_string (s^"\n"); flush ()
let caml_ml_output_char = print_char
let printf fmt = Printf.bprintf output_buffer_ fmt
module Printf = struct
    include Printf
    let printf fmt = Printf.bprintf output_buffer_ fmt
end

- URL-, -. Ocaml Sys, ?argv .

module Sys = struct
    let char_split delim s = (*Str.split is overkill*)
        let hd = ref "" in let l = ref [] in 
        String.iter (fun c -> 
            if c = delim
            then  (l := (!hd)::(!l); hd := "")
            else hd := (!hd) ^ (String.make 1 c)
        ) s;
        List.rev ((!hd)::(!l)) 
    let getenv x = List.assoc x Url.Current.arguments
    let argv = Array.of_list (char_split '\x00' (getenv "?argv"))
    let executable_name = argv.(0)
end

, , OCaml:

(* cli.ml *)
let _ = print_string (Array.fold_left (^) "" (Array.make 40 (String.lowercase (Sys.argv.(1)^"\n"))) )

, . , Javascript , . , .

(* JsFooter.ml *)
let _ = flush stdout; print_endline "\x00"

:

 cat JsHeader.ml cli.ml JsFooter.ml > merged.ml
 ocamlbuild -use-menhir -menhir "menhir" \
   -pp "camlp4o -I /opt/local/lib/ocaml/site-lib js_of_ocaml/pa_js.cmo" \
   -cflags -I,+js_of_ocaml,-I,+site-lib/js_of_ocaml -libs js_of_ocaml \
   -lflags -I,+js_of_ocaml,-I,+site-lib/js_of_ocaml merged.byte
 js_of_ocaml merged.byte

, merged.js, javascript -, :

<html>
<head>
<meta http-equiv="Content-Type" content="text/xhtml+xml; charset=UTF-8" />
<title>ml2js sample_cli</title>
<script type="text/javascript">
<!--
var worker;
function go () {
  var output=document.getElementById ("output");
  var argv = encodeURIComponent("/bin/sample_cli\0"+document.getElementById ("input").value);
  if (worker) {
    worker.terminate();
  }
  worker = new Worker ("sample_cli.js?argv="+argv);
  document.getElementById ("output").value="";
  worker.onmessage = function (m) {
    if (typeof m.data == 'string') {
    if (m.data == "\0\n") {
        output.scrollTop = output.scrollHeight
    } else {
        output.value+=m.data;
    }
    }
  }
}
//-->
</script>
</head>

<body onload=go()>
<textarea id="input" rows="2" cols="60" onkeyup="go()" onchange="go()" style="width:90%">SAMPLE_INPUT</textarea> 
<button onclick="go()">go</button><br>
<textarea id="output" rows="0" cols="60" style="width:100%;height:90%" readonly onload=go()>
Your browser does not seem to support Webworkers.
Try Firefox, Chrome or IE10+. 
</textarea>
</body>

</html>

. http://www.dansted.org/app/bctl-plain.html https://github.com/gmatht/TimeLogicUnify/blob/master/ATL/js/webworker/ml2js.sh script, , ..

+3

js_of_ocaml ? caml_ml_output_char. node sys.argv. Sys.argv [| "a.out" |]. , GitHub https://github.com/ocsigen/js_of_ocaml/issues/new, .

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