Source file builtins_eval.ml

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(*****************************************************************************

  Liquidsoap, a programmable audio stream generator.
  Copyright 2003-2023 Savonet team

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details, fully stated in the COPYING
  file at the root of the liquidsoap distribution.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA

 *****************************************************************************)

let raise exn =
  let bt = Printexc.get_raw_backtrace () in
  Lang.raise_as_runtime ~bt ~kind:"eval" exn

let _ =
  Lang.add_builtin ~category:`Liquidsoap "_eval_"
    ~descr:"Parse and evaluate a string." ~flags:[`Hidden]
    [("type", Value.RuntimeType.t, None, None); ("", Lang.string_t, None, None)]
    (Lang.univ_t ())
    (fun p ->
      let ty = Value.RuntimeType.of_value (List.assoc "type" p) in
      let scheme = Typing.generalize ~level:(-1) ty in
      let ty = Typing.instantiate ~level:(-1) scheme in
      let s = Lang.to_string (List.assoc "" p) in
      try Runtime.eval ~ignored:false ~ty s with exn -> raise exn)