aureooms/js-integer-little-endian

/**
 * @param {int} r base (radix)
 */
export function bsub_t (r){

    /**
     * Subtracts two big endian arrays, k >= i >= j
     * wraps
     *
     * @param {array} a first operand
     * @param {int} ai a left
     * @param {int} aj a right
     * @param {array} b second operand
     * @param {int} bi b left
     * @param {int} bj b right
     * @param {array} c result, must be 0 initialized
     * @param {int} ci c left
     * @param {int} cj c right
     */

    return function(a, ai, aj, b, bi, bj, c, ci, cj){
        var T, C = 0;

        while(--bj >= bi){
            --aj; --cj;
            T = C;
            C = a[aj] < b[bj] + T;
            c[cj] = a[aj] - b[bj] + (C*r - T);
        }

        while(--aj >= ai){
            --cj;
            T = C;
            C = a[aj] < T;
            c[cj] = a[aj] + (C*r - T);
        }

        if(C){
            while(--cj >= ci){
                c[cj] = r - 1;
            }
        }

    };
}


/**
 * @param {int} r base (radix)
 */
export function lsub_t (r){

    /**
     * Subtracts two little endian arrays, k >= i >= j
     * wraps
     *
     * @param {array} a first operand
     * @param {int} ai a left
     * @param {int} aj a right
     * @param {array} b second operand
     * @param {int} bi b left
     * @param {int} bj b right
     * @param {array} c result, must be 0 initialized
     * @param {int} ci c left
     * @param {int} cj c right
     */

    return function(a, ai, aj, b, bi, bj, c, ci, cj){
        var T, C = 0;

        while(bi < bj){
            T = C;
            C = a[ai] < b[bi] + T;
            c[ci] = a[ai] - b[bi] + (C*r - T);
            ++ai; ++bi; ++ci;
        }

        while(ai < aj){
            T = C;
            C = a[ai] < T;
            c[ci] = a[ai] + (C*r - T);
            ++ai; ++ci;
        }

        if(C){
            while(ci < cj){
                c[ci] = r - 1;
                ++ci;
            }
        }

    };
}