问题描述
在CoffeeScript中，有时我需要调用;然而，参数的不幸排序意味着初始/默认值在reduce函数本身之后，这意味着我必须使用大量的括号，这看起来比CoffeeScript要难得多。
In CoffeeScript sometimes I need to call Array.reduce(...) with a default value; however, the unfortunate ordering of the arguments means the initial/default value goes after the reduce function itself, which means I've got to use a lot of parens, which seems much uglier than CoffeeScript wants to be.
例如：
items = [ (id:'id1', name:'Foo'), (id:'id2', name:'Bar') ] # ...
itemsById = items.reduce(((memo, item) -> # <-- Too many parens!
memo[item.id] = item
memo), {}) # Ugly!
在CS中有更多惯用的方法吗？
Is there a more idiomatic way to do this in CS?
推荐答案
我自己和其他函数一起运行。如果它真的做了一些东西（或者它只是真的困扰我），我可能声明函数在其他地方（也许在该行之上），然后传递函数作为参数，像这样：
I've run in to this myself with other functions. In cases where its really made a mess of things (or it just really bothers me), I might declare the function elsewhere (perhaps above that line), and then pass the function as a parameter, something like so:
reduce_callback = (memo, item) ->
memo[item.id] = item
memo
itemsById = items.reduce reduce_callback, {}
不幸的是，你需要垂直扩展，这可能是可能的，也可能不是。这只是一个一般的建议。
Unfortunately, you expand a whole lot vertically, which may or may not be desirable. This is merely a general suggestion.
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