someone who believes in and follows very traditional rules or ideas about a subject

Although purists may object to split infinitives, like "to boldly go", the fact is, they are commonly used. 尽管讲究语言规范的人会反对分离不定式，比如 to boldly go，可事实是这种用法很普遍。

Purists eat smoked salmon with nothing more than lemon and black pepper. 讲究口味纯正的人吃熏鲑鱼时除了柠檬和黑胡椒什么也不加。