aureooms/js-integer-little-endian

/**
 * Function template for number parsing.
 * Endianess provided by the iterator function
 * iterator function must be reverse ordered
 *
 * @param {int} t to radix
 * @param {int} f from radix
 * @param {function} iter iterator function
 */


export function parse_t ( t , f , iter ) {

    if(t >= f){

        if(f > 36) throw new Error('f > 36 not implemented');

        var z = 0, log = t;
        while(log >= f){
            if (log % f) break;
            log /= f;
            ++z;
        }

        if (log !== 1) throw new Error('log(f) does not divide log(t) not implemented');

        // immediate log(t) divides log(f)
        return function(s, si, sj, a, ai, aj){
            var len = sj - si, k = sj - z, n = Math.ceil(len / z);
            var block = function(i){
                a[i] = parseInt(s.slice(Math.max(0, k), k + z), f);
                k -= z;
            };

            iter(aj - n, aj, block);

        };

    }
    else throw new Error('f > t not implemented');


}