问题描述
我是否遗漏了 Array 文档中的某些内容?我有一个数组，其中最多包含一个满足某个标准的对象.我想有效地找到那个对象.我从文档中得到的最好的想法是:
Am I missing something in the Array documentation? I have an array which contains up to one object satisfying a certain criterion. I'd like to efficiently find that object. The best idea I have from the docs is this:
candidates = my_array.select { |e| e.satisfies_condition? }
found_it = candidates.first if !candidates.empty?
但我不满意有两个原因:
But I am unsatisfied for two reasons:
那个select 让我遍历了整个数组，尽管我们本可以在第一次命中后放弃.我需要一行代码(带有条件)来扁平化候选人.
That select made me traverse the whole array, even though we could have bailed after the first hit.
I needed a line of code (with a condition) to flatten the candidates.
这两种操作都是浪费的，因为预先知道有 0 或 1 个令人满意的对象.
Both operations are wasteful with foreknowledge that there's 0 or 1 satisfying objects.
我想要的是这样的:
array.find_first(block)
它返回 nil 或该块计算为真的第一个对象，结束对该对象的遍历.
which returns nil or the first object for which the block evaluates to true, ending the traversal at that object.
我必须自己写吗?Array 中所有其他很棒的方法让我觉得它就在那里，我只是没有看到它.
Must I write this myself? All those other great methods in Array make me think it's there and I'm just not seeing it.
推荐答案
要么我不明白你的问题，要么 Enumerable#find 就是你要找的东西.
Either I don't understand your question, or Enumerable#find is the thing you were looking for.