1const Readable = require("stream").Readable;
 2
 3module.exports = function streamFromArrayTxt(ma) {
 4    const  rs = Readable();
 5
 6    let curIndex = getFirstIdx(ma);
 7
 8    rs._read = function() {
 9        let res;
10        res = objFromIdx(ma, curIndex);
11        curIndex = nextIdx(curIndex);
12        if (res!==null) {
13            rs.push(res + "\n");
14        } else {
15            rs.push(null);
16        }
17    };
18
19
20    return rs;
21
22
23    function getFirstIdx(ma) {
24        if (typeof ma.push !== "function" ) return [];
25        return [0, ...getFirstIdx(ma[0])];
26    }
27
28    function nextIdx(idx) {
29        if (idx == null) return null;
30        if (idx.length == 0) return null;
31
32        const parentIdx = idx.slice(0,-1);
33
34        const itObj = objFromIdx(ma, parentIdx);
35        const newLastIdx = idx[idx.length-1]+1;
36        if (newLastIdx < itObj.length) {
37            const resIdx = idx.slice();
38            resIdx[resIdx.length-1] = newLastIdx;
39            return [...resIdx, ...getFirstIdx(itObj[newLastIdx])];
40        } else {
41            return nextIdx(parentIdx);
42        }
43    }
44
45    function objFromIdx(ma, idx) {
46        if (idx == null) return null;
47        if (idx.length == 0) return ma;
48        if (ma.length == 0) return "";
49        return objFromIdx(ma[idx[0]], idx.slice(1));
50    }
51};