I think you mean s-expressions instead of lisp and if you do, I'm with you. They are really neat and underused. Now, if you want to carry a whole language runtime for the structured data format you'll probably end up with the "which lisp" kind of problem in which each app end up using something different and then the structured data files are no longer exactly portable (until you devise a portable standard yadayadayada)
I have to admit, once you've seen S-expressions, XML looks insanely bloated and verbose.
The advantage XML would have in that situation is that, because it's so verbose, if you get a malformed XML, you can eyeball-parse it and often figure out how to hand-edit it to make it valid. If it is valid, you can also see exactly how the schema you were sent differs from the schema you expected. An S-expression, having less redundancy, also is potentially more brittle.
If malforming is regular (like someone printf’d or typed in bad xmls), then the same is true for any human-readable format, since you know data and what it should look like. If not, (like in randomly broken packet), then you solve the problem at the wrong level. By-hand error-correcting verbosity is hardly a selling point of the application level protocol.
> By-hand error-correcting verbosity is hardly a selling point of the application level protocol.
It's a selling point while you're trying to figure out how to get it working. Once you have it working, it's not - but by then, you have it working, so why change it?
