Exercism: "Grade School in Clojure"

This is my solution to the Grade School problem in Clojure:

The first working version:

	(ns school)
	(defn grade [school grade-num]
	(get school grade-num []))
	(defn add [school name grade-num]
	(assoc
	school
	grade-num
	(conj (grade school grade-num) name)))
	(defn sorted [school]
	(into {}
	(map
	(fn [[grade students]]
	[grade (sort students)])
	(sort-by key school))))

view raw school1.clj hosted with ❤ by GitHub

Trying to improve its readability I introduced two local helpers in the sorted function:
sort-by-grades and sort-students-by-name.

This is the resulting version:

	(ns school)
	(defn grade [school grade-num]
	(get school grade-num []))
	(defn add [school name grade-num]
	(assoc
	school
	grade-num
	(conj (grade school grade-num) name)))
	(defn sorted [school]
	(let
	[sort-by-grades
	(partial sort-by key)
	sort-students-by-name
	(partial map
	(fn [[grade students]]
	[grade (sort students)]))]
	(into
	{}
	(sort-students-by-name
	(sort-by-grades school)))))

view raw school2.clj hosted with ❤ by GitHub

Finally, I experimented with the -> macro to see its effect on readability and got to this last version:

	(ns school)
	(defn grade [school grade-num]
	(get school grade-num []))
	(defn add [school name grade-num]
	(assoc
	school
	grade-num
	(conj (grade school grade-num) name)))
	(defn sorted [school]
	(let
	[sort-by-grades
	(partial sort-by key)
	sort-students-by-name
	(partial map
	(fn [[grade students]]
	[grade (sort students)]))]
	(into
	{}
	(->
	school
	sort-by-grades
	sort-students-by-name))))

view raw school3.clj hosted with ❤ by GitHub

I think the -> macro is great.

You can nitpick my solution here or see all the exercises I've done so far in this repository.