Episode 77 - links instead of a for loop

Question

In episode 77 Joel and Jeff were discussing using links instead of a for loop. I looked in Stack Overflow, Google, and Wikipedia but couldn't find any reference to a links construct. The closest thing I could find was a self referencing linked list which would presumably loop indefinitely. Is links a feature of the Links programming language? If not, what was meant by links in this context.

Answer 1

Yes, I'm pretty sure they said LINQ.

In .Net it's a pretty useful feature allowing you essentially "select" items from an object collection using syntax that looks suspiciously like SQL:

List<Person> personList = // maybe passed into a method or whatever
IEnumerable<Person> filteredList = from p in personList
                                   where p.Age > ageThreshold
                                   select p
return filteredList.ToList<Person>();

There's a great Manning book on it: "LINQ in Action" and they have some sample downloadable chapters if you want to learn more.

Answer 2

I'm sure that they were talking about using LINQ (Language INtegrated Query), not links, to replace foreach loops.

var stuff = list.Where( l => l.StartsWith( "a" ) ).ToList();

or

var stuff = (from l in list
            where l.StartsWith("a")
            select l).ToList();

vs

var stuff = new List<string>();
foreach (var item in list)
{
    if (item.StartsWith("a"))
    {
         stuff.Add( a );
    }
}