C'mon zippers are not that hard, and really useful.
Lets say you want to do processing of some xml file.
Normally you'd walk the tree and do manipulations in place.
With zippers however, you can inspect every intermediary tree result, you can rethink you problem so that you walk the tree once to extract interesting information, then compute a changeset for the tree, maybe merge it with a differently computed changeset, and then apply the union of them.
I build a ocr system in clojure on zippers and it was a lot of fun. You could for example extract a list of all the words, with line wraps removed, then do the correction on that view/lense of your data, and reapply the changes without having to worry to reintroduce the pesky linewraps, because they were never removed from the original document.
Lets say you want to do processing of some xml file. Normally you'd walk the tree and do manipulations in place. With zippers however, you can inspect every intermediary tree result, you can rethink you problem so that you walk the tree once to extract interesting information, then compute a changeset for the tree, maybe merge it with a differently computed changeset, and then apply the union of them.
I build a ocr system in clojure on zippers and it was a lot of fun. You could for example extract a list of all the words, with line wraps removed, then do the correction on that view/lense of your data, and reapply the changes without having to worry to reintroduce the pesky linewraps, because they were never removed from the original document.