Every --- Doing Something Occasionally

Every — Doing Something Occasionally

I recently had a need for a class I wrote a long time ago in C++. But I was working in C#, so I had to recreate it. Fortunately. with lambdas and closures. the C# version was much easier than the last one.

Sometimes, when looping through a large collection, you need to do something – like pagination or a progress message, not on every iteration, but only after a number of them. Normally, we’d do something like this:

 int counter = 0;
 foreach(var item in MyLongList)
 {
       DoSomethingWith(item);
       ++counter;
       if (counter % 100 == 0)
       {
            Console.WriteLine($"We've completed {counter} items.");
       }
 }

For that, we have the Every class.

Basic usage:

   var progress = new Every(100, (total) => Console.WriteLine($"We've completed {total} items.");
   foreach(var item in MyLongList)
   {
          Process(item);
          ++progress;
   }

In that example, every 100th time ++progress is called, our reassuring message is printed, with the total number of item processed.

That’s pretty much the lot of it. You can write ++progress or progress++ or if you prefer something a bit more verbose, progress.Next(). All three are equivalent.

There’s a CallNow() method, which does exactly that. (Use it after the loop, to, say, print the total number processed.)

And Reset() starts the count over from the beginning.

The constructor takes the number of iterations between calls the the Action, and a Action<int> (normally a lambda, but it could be a named method also) and takes an int (which will be equal to the total number of calls), and does whatever you need.

Full source code on my Githib: https://github.com/jamescurran/Every