readAsync from WinRT socket

gistfile1.txt

readLineAsync = function(reader, timeout, buffer) {
      var byte;
      if (buffer == null) {
        buffer = "";
      }
      logger.trace("readLineAsync: reader.unconsumedBufferLength=" + reader.unconsumedBufferLength + " buffer=" + buffer);
      while (reader.unconsumedBufferLength) {
        byte = reader.readByte();
        if (byte === 0) {
          logger.trace("End of stream reached, " + reader.unconsumedBufferLength + " left on reader");
          return WinJS.Promise.as(buffer);
        }
        buffer += String.fromCharCode(byte);
      }
      logger.trace("readLineAsync: reading 4096 bytes");
      return WinJS.Promise.timeout(timeout, reader.loadAsync(4096)).then(function(readBytes) {
        logger.trace("readLineAsync: more " + readBytes + " read");
        if (readBytes === 0) {
          logger.trace("readLineAsync: 0 bytes read, returning " + buffer);
          return WinJS.Promise.as(buffer);
        } else {
          logger.trace("readLineAsync: call again with " + buffer + " and " + reader.unconsumedBufferLength + " left on reader");
          return WinJS.Promise.timeout().then(function() {
            return readLineAsync(reader, timeout, buffer);
          });
        }
      }, function(error) {
        if (error.name === "Canceled") {
          error.timeout = true;
          logger.trace("readLineAsync: Canceled or timed-out");
        } else {
          logger.trace("readLineAsync: error", error);
        }
        return WinJS.Promise.wrapError(error);
      });
    }; 
    
  lastLinePattern = /^\|0?18\|05\|00\|02\|\|$/;
    readXmlAsync = function(reader, timeout) {
      var done, xml;
      xml = "";
      done = false;
      return new WinJS.Promise(function(c, e, p) {
        var runner;
        runner = function() {
          if (done) {
            return c(hex2a(xml));
          } else {
            return readLineAsync(reader, timeout).then(function(line) {
              p(line);
              if (lastLinePattern.test(line)) {
                return done = true;
              } else {
                return xml += line;
              }
            }).then(runner, e, p);
          }
        };
        return runner();
      });
    };