When I was first starting out a very long time ago, I wrote a lot of Fortran (mainly for digital signal processing applications), and a couple of times I had to

When I was first starting out a very long time ago, I wrote a lot of Fortran (mainly for digital signal processing applications), and a couple of times I had to work around the lack of recursion by building my own stacks for intermediate results, with arrays and a position to keep track of where I was. It was ugly.