事实上，真正发生的事情是：在函数语言中，就像变量和常量一样，函数是一级概念，所以语法上也是一样地处理。

In fact, this is precisely what's taking place: in a functional language, functions are first-class concepts, like variables and constants, and so are syntactically treated as such.

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函数式语言中的函数称为一级函数，这意味着函数可在任何其他语言结构(比如变量)可能出现的地方出现。

Functions in a functional language are considered first class, meaning that functions can appear anywhere that any other language construct (such as variables) can appear.

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