返回键，具有动态键名称的值对象

在PEG.js中，我有以下规则

In PEG.js I have the following rule

label  = l:[a-zA-Z\$\#\% ]*  { return word(l); } 
block  = "[" l:label "]" { return l; }
option = "\n"* key:block value:label "\n"? {return {key : value}; } 

如果解析[hello] world，则结果为:

{"key": "world"}.

我希望它回来

{"hello": "world"}.

这可能吗?如何确保对象键接受动态值.

Is this possible? How can I make sure the object key accepts a dynamic value.