Function runInOp

static/js/codemirror/codemirror.js:1305–1311

(cm, f)

    };
  }
  function runInOp(cm, f) {
    var withOp = !cm.curOp, result;
    if (withOp) startOperation(cm);
    try { result = f(); }
    finally { if (withOp) endOperation(cm); }
    return result;
  }

  function regChange(cm, from, to, lendiff) {
    if (from == null) from = cm.doc.first;