[time_management]

Clojure uses {} for maps, #{} for sets, and [] for vectors, and vectors are used in function definitions, let statements, etc. This slight decrease in regularity makes a lot of functionality more visible. For example:

SBCL:

(defun f (x y) (let ((z (gethash x :a))) (+ z y))

Clojure

(defn f [x y] (let [z (get x :a)] (+ x y)))

Having syntax for maps is a huge win. Like ML's pattern matching, it's one of those things that changes your coding style entirely for the better, in a way that you wouldn't predict just by looking at the feature.

The only think I miss from CL when I work in Clojure is keyword arguments to functions. There, the Clojure way is a bit worse:

(defun f (x &key y z) (list x y z)) (f 2 :z 3) => (2 nil 3)

(defn f [x {y :y z :z}] (list x y z)) (f 2 {:z 3}) => (2 nil 3)

[anamax]

> (defun f (x y) (let ((z (gethash x :a))) (+ z y))

vs

> (defn f [x y] (let [z (get x :a)] (+ x y)))

The CL defn of f is a function that is called with two arguments. That function is called like "(f a b)" If the Clojure definition is comparable, that is, the call looks like "(f a b)", why are []s used in the definition and the let?

> This slight decrease in regularity makes a lot of functionality more visible.

What functionality? x,y aren't part of a vector and neither is z. (x,y may come from a vector in the caller, but I'll assume that the defn works if they don't, so that shouldn't matter.)