Function lineStartSmart

static/editor.md/lib/codemirror/lib/codemirror.js:8392–8402

(cm, pos)

    return Pos(lineN == null ? lineNo(line) : lineN, ch);
  }
  function lineStartSmart(cm, pos) {
    var start = lineStart(cm, pos.line);
    var line = getLine(cm.doc, start.line);
    var order = getOrder(line);
    if (!order || order[0].level == 0) {
      var firstNonWS = Math.max(0, line.text.search(/\S/));
      var inWS = pos.line == start.line && pos.ch <= firstNonWS && pos.ch;
      return Pos(start.line, inWS ? 0 : firstNonWS);
    }
    return start;
  }

  function compareBidiLevel(order, a, b) {
    var linedir = order[0].level;