concept map entry in category clojure

This is an excerpt from Manning's book The Joy of Clojure, Second Edition. Login to get full access to this book.

Vectors are probably the most frequently used collection type in Clojure code. They’re used as literals for argument lists and let bindings, for holding large amounts of application data, as stacks, and as map entries. We’ll also address efficiency considerations, including growing on the right end, subvectors, and reversals, and finally we’ll discuss cases in which vectors aren’t an optimal solution.

5.2.6. Vectors as map entries

Clojure’s hash map, just like hash tables or dictionaries in many other languages, has a mechanism to iterate through the entire collection. Clojure’s solution for this iterator is, unsurprisingly, a seq. Each item of this seq needs to include both the key and the value, so they’re wrapped in a map entry. When printed, each entry looks like a vector:^[10]