Clojure:从匿名函数返回一个向量 [英] Clojure: returning a vector from an anonymous function

问题描述

我编写了一个小型匿名函数，用于 map 调用.该函数返回一个向量，其中包含来自 SQL 结果集查询的列名和列值.

I wrote a small anonymous function to be used with a map call. The function returns a vector containing a column name and column value from a SQL result set query.

这里是函数(输入的是列名):

Here is the function (input is the column name):

(fn [name] [(keyword name) (.getObject resultset name)])

这很好用，但是当我尝试使用匿名函数的简化"版本时，出现错误:

This works fine, however when I tried to use a "simplified" version of the anonymous function, I got an error:

#([(keyword %) (.getObject resultset %)])

java.lang.IllegalArgumentException: Wrong number of args (0) passed to: PersistentVector

这是map调用:

(into {} (map (fn [name] [(keyword name) (.getObject resultset name)]) column-names))

是否可以对这个函数使用简化的语法?如果是这样，如何?

Is it possible to use the simplified syntax for this function? If so, how?

谢谢.

推荐答案

你的问题是简单的语法试图将向量作为函数调用来求值.

Your problem is that the simple syntax is trying to evaluate the vector as a function call.

你可以插入一个identity"函数来让它工作，因为这只是一个简单的函数，它将返回不变的向量:

You can insert an "identity" function to make it work, as this is just a simple function that will return the vector unchanged:

#(identity [(keyword %) (.getObject resultset %)])

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