It's the kind of thing that is more useful in an image-based language. It can be very useful for debugging a running instance you've invested a lot of effort i

It's the kind of thing that is more useful in an image-based language. It can be very useful for debugging a running instance you've invested a lot of effort in. I've never used it in production code though. You could compare it to using a debugger to change the value of a variable in C or C++ in order to proceed with a program's run. For instance, you might notice that a your program should have updated a variable to correspond to some other data that was updated, so you make a mental note to add some code that will do that, manually change the variable yourself, and proceed. Edit: this post is probably a response to the recent post on the same topic: https://news.ycombinator.com/item?id=9928485 https://news.ycombinator.com/item?id=9928485