aureooms/js-integer-little-endian

export function bdiv_t (lt, sub){

    /**
     * Computes quotient and remainder of two big endian arrays.
     * <p>
     * Computes quotient and remainder of two big endian arrays
     * using long division algorithm (the one teached in
     * european primary schools).
     *
     * /!\ This algorithm modifies its first operand.
     *
     * HYP : q is at least as large as r
     *       b is not zero
     *
     * @param {array} r dividend and remainder
     * @param {int} ri r left
     * @param {int} rj r right
     * @param {array} b divisor
     * @param {int} bi b left
     * @param {int} bj b right
     * @param {array} q quotient, must be 0 initialized
     * @param {int} qi q left
     */

    // /!\ There are implicit hypotheses
    //     made on the size of the operands.
    //     Should clarify.

    var div = function(r, ri, rj, b, bi, bj, q, qi){
        var k, t = ri + 1;

        do {

            // trim leading zeros
            //     - maybe could try to put this procedure inside the sub loop
            //     - or assume that the number is trimed at the begining
            //       and put this statement at the end of the main loop
            while (ri < rj && r[ri] === 0) ++ri;

            // search for a remainder block interval
            // greater than the divisor
            //     - maybe could try binary search on the lt function
            //     for another implementation
            k = ri + 1;
            while (k <= rj && lt(r, ri, k, b, bi, bj)) ++k;

            // remainder smaller than divisor --> end
            if (k > rj) break;

            // divide current block interval by quotient
            do{

                // increment quotient block corresponding
                // to current ls block of remainder interval
                ++q[qi + k - t];

                // subtract divisor from current remainder
                // block interval
                sub(r, ri, k, b, bi, bj, r, ri, k);

            } while(!lt(r, ri, k, b, bi, bj));


        } while(true);

    };

    return div;

}