Why is the LINQ "apply-to-all" method named Select?

Question

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.

Map

Answer 1

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

is translated to:

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

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

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

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.

Answer 2

One of the major reasons Select comes last is to make Intellisense work. By putting the source of the sequence first (from statement), Intellisense can work properly.