site/blog/voiding-the-interview-2017-04-16.md

title	date
Voiding the Interview	2017-04-16

Voiding the Interview

A young man walks into the room, slightly frustrated-looking. He's obviously had a bad day so far. You can help him by creating a new state of mind.

"Hello, my name is Ted and I'm here to ask you a few questions about your programming skills. Let's start with this, in a few sentences explain to me how your favorite programming language works."

Starting from childhood, you eagerly soaked up the teachings of your mentors, feeling the void separated into sundry shapes and sequences. They taught you many specific tasks to shape the void into, but not how to shape it. Studying the fixed ways of the naacals of old gets you nowhere, learning parlor tricks and saccharine gimmicks. Those gimmicks come rushing back, you remembering how to form little noisemakers and amusement vehicles. They are limiting, but comforting thoughts.

You look up to the interviewer and speak:

"In the beginning there was the void, Spirit was with the void and Spirit was everpresent in the void. The void was cold and formless; the cold unrelenting even in today's age. Mechanical brains cannot grasp this void the way Spirit can; upon seeing it that is the end of that run. In this way the void is the beginning and the end, always present, always around the corner."

(def void ())

"What is that?"

> void
>

"But that's...nothing."

You look at the caucasian man sitting across from you, and emit "nothing is something, a name for the void still leaves the void extant."

"...Alright, let's move on to the next question. This is a formality but the person giving you the phone interview didn't cover fizzbuzz. Can you do fizzbuzz?"

Stepping into the void, you recall the teachings of your past masters. You equip the parentheses once used by your father and his father before him. The void divides before your eyes in the way you specify:

(defn fizzbuzz [n]
  (cond
    (= 0 (mod n 15)) (print "fizzbuzz")
    (= 0 (mod n 3))  (print "fizz")
    (= 0 (mod n 5))  (print "buzz")
    (print n))
  (println ""))

"This doesn't loop from 0 to n though, how would you do that?"

You see this section come to life, it gently humming along, waiting for it to be used. Before you you see two ancient systems spring from the memories of patterns once wielded in conflict with complexity.

"Apply this function to span of values."

> (range 17)
error in __main:0: symbol {range 71} not found

You realize your error the moment you press for confirmation. "Again, in the beginning there is the void. What doesn't exist needs to be separated out from it." The voidspace in your head was out of sync with the voidspace of the machine. Define them.

"...Go on"

(defn range-inner [x lim xs]
  (cond
    (>= x lim) xs
    (begin
      (aset! xs x x)
      (range-inner (+ x 1) lim xs))))

(defn range [lim]
  (range-inner 0 lim (make-array lim)))

> (range 17)
[0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16]

"Great, now you have a list of values, how would you get the full output?"

"Pass the function as an argument, injecting the dependency."

(defn do-array-inner [f x i]
  (cond
    (= i (len x)) void
    (let [val (aget x i)]
      (f val)
      (apply-inner f x (+ i 1)))))

(defn do-array [f x]
  (do-array-inner f x 0))

> (do-array fizzbuzz (range 17))
fizzbuzz
1
2
fizz
4
buzz
fizz
7
8
fizz
buzz
11
fizz
13
14
fizzbuzz
16

Your voidspace concludes the same, creating a sense of peace. You look in the man's eyes, being careful to not let the fire inside you scare him away. He looks like he's seen a ghost. Everyone's first time is rough.

Everything has happened and will happen, there is nothing new in the universe. You know what's going to happen. They will decline, saying they are looking for a better "culture fit". They couldn't contain you.

To run the code in this post:

$ go get github.com/zhemao/glisp
$ glisp
> [paste in blocks]