Say I have a map {:x 1}.
I noticed that I can lookup :x either by applying it to the map:
(:x {:x 1})
;=> 1
或通过将地图应用于关键字：
({:x 1} :x)
;=> 1
两种形式有什么区别？
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Say I have a map {:x 1}.
I noticed that I can lookup :x either by applying it to the map:
(:x {:x 1})
;=> 1
或通过将地图应用于关键字：
({:x 1} :x)
;=> 1
两种形式有什么区别？
Both maps and keywords implement
IFnand therefor can be used as functions. The function they implement isget. So it basically always translates to(get map key default).因此，有一些自己可以弥补的经验法则；要考虑的一些事情：
({"a" 1} "a"))(nil {:a 1})fails, but({:a 1} nil)works); if you are unsure about both: useget