onlurking

Programming as Theory Building

Peter Naur

Peter Naur's classic 1985 essay "Programming as Theory Building" argues that a program is not its source code. A program is a shared mental construct (he uses the word theory) that lives in the minds of the people who work on it. If you lose the people, you lose the program. The code is merely a written representation of the program, and it's lossy, so you can't reconstruct

maacl

(ns pms.core
  (:require [clojure.spec.alpha :as s]
            [clojure.spec.gen.alpha :as gen]
            [clojure.spec.test.alpha :as stest]))

(comment "This is a small experiment inspired by Oskar Wickströms
  excellent work at
  https://haskell-at-work.com/episodes/2018-01-19-domain-modelling-with-haskell-data-structures.html. I
  wanted to see what would be involved in building the equivalent
  functionality in reasonably ideomatic Clojure. It is also my first

lazywithclass

Looking at the most beautiful program ever written - part 1

I am going to have a look at what William Byrd presented as The most beautiful program ever written.

Beauty here refers to computer programs, specifically about Lisp. There might be errors as this is something I wrote to make sense of that interpreter, proceed at your own risk.

Thanks a lot to Carl J. Factora for the help.

The program

halgari

The question was asked why I (as a programmer who prefers dynamic languages) don't consider static types "worth it". Here
is a short list of what I would need from a type system for it to be truely useful to me: 

1) Full type inference. I would really prefer to be able to write: 

(defn concat-names [person]
  (assoc person :full-name (str (:first-name person)
                                (:second-name person))))

And have the compiler know that whatever type required and produced from this function was acceptible as long as the 

kevin-smets

Default

Powerlevel10k

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs