The tradition in the lisp world is to write a metacircular evaluator, which is approximately the most braindead thing that you could actually call a 'compiler'.

The tradition in the lisp world is to write a metacircular evaluator, which is approximately the most braindead thing that you could actually call a 'compiler'. Similar concepts apply in day to day work, if you want to have some fun with compilers. You can almost certainly use a parser in your day to day work. You've got log files, config files, some sort of routine tedious job that involves taking free text and turning it into useful data structures of some kind. They don't have to be complex - it's entirely possible to write a few-line validator and transformer for (say) CSV user input.