There are a handful of other valid uses, but there are many invalid ones. I recall, a couple of years ago, hearing about a Rails vulnerability caused by some API method calling 'eval' on one of its arguments if it happened to be a string, just as a convenience for some use case. The fact that it did so wasn't even documented. I was left with the impression that most programmers don't understand how to use 'eval', or rather, how and why not to use it.