为什么LINQ“全部应用"?名为Select的方法? [英] Why is the LINQ "apply-to-all" method named Select?

问题描述

当我阅读使用Select的代码时，我认为是全选". 当我阅读使用Map的代码时，我会认为此到那个"或全部应用". 我不能成为唯一一个感到Select这个名字令人困惑的人.

When I read code that uses Select I think "select-all-where". When I read code that uses Map I think "this-to-that" or "apply-to-all". I can't be the only person that feels the name Select is confusing.

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推荐答案

它与功能语言中的映射完全相同.之所以命名为Select，是因为它被设计为LINQ的一部分，而LINQ使用的是类似SQL的关键字.

It's really identical to map from functional languages. The reason it's named Select is that it's designed to be used as a part of LINQ which uses SQL-like keywords.

from item in collection
where item.Value == someValue
select item.Name

被翻译为:

collection.Where(item => item.Value == someValue)
          .Select(item => item.Name)

如果Select被命名为Map，将会有点不一致；像这样:

it would be a little inconsistent if Select was named Map; something like:

collection.Filter(item => item.Value == someValue)
          .Map(item => item.Name)

实际上，许多人完全不使用函数式编程就使用LINQ.对于他们来说，LINQ是一种检索数据对象并轻松查询它们的方法(就像SQL查询一样).对于他们来说，Select和Where是很有意义的.比Map和Filter多得多.

In fact, many people use LINQ without having heard of functional programming at all. To them, LINQ is a method to retrieve data objects and query them easily (like SQL queries are). To them, Select and Where make perfect sense. Much more than Map and Filter.

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