caml_utils.ml

(* Copyright (C) 2015-2016 Bloomberg Finance L.P.
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * In addition to the permissions granted to you by the LGPL, you may combine
 * or link a "work that uses the Library" with a publicly distributed version
 * of this file to produce a combined library or application, then distribute
 * that combined work under the terms of your choosing, with no requirement
 * to comply with the obligations normally placed on you by section 4 of the
 * LGPL version 3 (or the corresponding section of a later version of the LGPL
 * should you choose to use a 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)






(** *)

(* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/imul *)


let repeat : int -> string -> string [@bs] = [%bs.raw{| (String.prototype.repeat && function (count,self){return self.repeat(count)}) ||
                                                  function(count , self) {
        if (self.length == 0 || count == 0) {
            return '';
        }
        // Ensuring count is a 31-bit integer allows us to heavily optimize the
        // main part. But anyway, most current (August 2014) browsers can't handle
        // strings 1 << 28 chars or longer, so:
        if (self.length * count >= 1 << 28) {
            throw new RangeError('repeat count must not overflow maximum string size');
        }
        var rpt = '';
        for (;;) {
            if ((count & 1) == 1) {
                rpt += self;
            }
            count >>>= 1;
            if (count == 0) {
                break;
            }
            self += self;
        }
        return rpt;
    }
|} ]



(*we need an attribute like this to prevent it get inlined *)