How to use infinity in your code

You’ll sometimes have to use the notion of infinity in your Ruby code. There isn’t any way to directly use infinity in Ruby, at least none that I know of… But there’s a tip to get it.

Let’s say that you have a next_row method which has to return next line of an infinite array – rows are added on the fly by another process.

In practice you’ll certainly use #loop but we’re going to use #each for the sake of demo.

def each
  0.upto(1.0/0.0) { yield next_row }
end

A quick test in IRB tells use that 1.0 / 0.0 is interpreted as Infinity:

>> 1.0/0.0
=> Infinity

To use Infinity directly without this trick you can use:

>> Float::INFINITY
=> Infinity

Now our #each implementation will loop forever. It’s definitively not the right solution to loop over elements but I thought it was interesting to know this little Ruby secret.