javascript sequential stdin reader.

reader.js

var reader = new Reader(10);
var input = {};
reader.read(function(line) {
  var vars = line.split(' ')
  input.m = parseInt(vars[0]);
  input.n = parseInt(vars[1]);
}).then(reader.read(function(line) {
  input.o = line;
})).then(function() {
  input.xs = [];
  var promise = Promise.resolve();
  for (var i = 0; i < input.m; i++) {
    promise = promise.then(reader.read(function(line) {
        input.xs.push(line);
      }));
  }
  return promise;
}).then(function() {
  reader.close();
  console.log('input: ');
  console.log(input); // main process
}).catch(function(e) {
  console.error(e);
});

function Reader(maxLines) {
  var lines = [];

  for (var i = 0; i < maxLines; i++) {
    var line = {
      resolve: null,
      setLine: function(line) { this.resolve(line); }
    }
    line.promise = new Promise(function(resolve) {
      line.resolve = resolve;
    })

    lines.push(line);
  }

  var reader = require('readline').createInterface({
      input: process.stdin,
      output: process.stdout
  });

  var initr = 0
  reader.on('line', function (line) {
    lines[initr].setLine(line);
    initr++;
  });

  var itr = 0
  this.read = function(func) {
    line = lines[itr];
    itr++;
    return line.promise.then(func)
  }
  this.close = function() {
    reader.close();
  }
}

$ node reader.js
3 2
foo
a
b
c
input:
{ m: 3, n: 2, o: 'foo', xs: [ 'a', 'b', 'c' ] }