I recently wrote a small 16-bit Forth for 8086 PCs running DOS. I built the basic one-liner loop words that can trivially be built with just "branch if zero" and "goto": begin, while, repeat, until, again. But I held off on implementing do / loop at first. It didn't seem like too much of a hardship. In a previous Forth I'd built, I'd implemented do / loop using the return stack, but it was... ugly. The code to implement it was ugly, the code it generated was ugly (and large!), and I didn't fi...
