let's go to the restaurant to eat something中的不定式to eat something是什么成分

问题描述:

let's go to the restaurant to eat something中的不定式to eat something是什么成分
是做目的状语还是做后置定语修饰前面的名词restaurant?
it's a good place to have fun.在这个句子里,不定式to have fun是做定语修饰place。

是作目的状语,因为去饭店的目的是吃东西,句意很明显.