miniblog.

Test code is total: we require it to always terminate or it's a failure! It also typically has 100% line and branch coverage. I feel way less nervous about refactoring tests, you can always just run them.

When a tool supports both regular expressions and literal strings, which should be the default? If you default to regex, users can match more strings than they realise (e.g. `foo.txt`) or less (e.g. `foo(bar)`). I typically see regex as the default, but I prefer the opposite.

ASTs typically discard comments, and that's usually what you want. The only time (AFAICS) that preserving comments is useful is for writing a code formatter. Could you write a formatter in terms of a list of lexemes? A CST is a non-trivial bit of code for one use case.