Adding a bit of context - as Clj data structures are immutable, changing something that is deeply nested cannot be done in-place (like in a Java set of nested

Adding a bit of context - as Clj data structures are immutable, changing something that is deeply nested cannot be done in-place (like in a Java set of nested objects - navigate until you find the one you need, call setFoo() on it, you're done). So it gets painful real quick. Specter is like search-and-replace - first you find all the elments you need, then you can replace / change them at the touch of a fn.