Case transforming macros
Casey transforms the case of given input idents.
Niche but maybe useful in other macros.
```rust
use casey::{pascal, lower, shouty, snake, upper};
lower!(ABC); // renders: abc
upper!(abc); // ABC
snake!(ABC); // a_b_c
pascal!(abc); // AbC
shouty!(ab_c); // A_B_C
```
Casey macros can operate on TokenStreams e.g.
rust
snake!(
struct MockStruct {}
impl MockStruct {
fn test() -> bool { true }
}
);
assert!(mock_struct::test());
All ident tokens in the stream will have the case transformation applied.