dpritchett

Programming as Theory Building

Peter Naur, 1985

(copied from http://alistair.cockburn.us/ASD+book+extract%3A+%22Naur,+Ehn,+Musashi%22)

Introduction

The present discussion is a contribution to the understanding of what programming is. It suggests that programming properly should be regarded as an activity by which the programmers form or achieve a certain kind of insight, a theory, of the matters at hand. This suggestion is in contrast to what appears to be a more common notion, that programming should be regarded as a production of a program and certain other texts.

dpritchett

irb(main):002:0> User.all
  User Load (1.0ms)  SELECT `users`.* FROM `users`
=> []
irb(main):003:0> Store.departments
  Store Load (0.0ms)  SELECT `stores`.* FROM `stores` WHERE `stores`.`is_store` = 0
=> []
irb(main):007:0> User.includes(:store).merge(Store.departments)
  User Load (1.0ms)  SELECT `users`.`id` AS t0_r0, `users`.`email` AS t0_r1,
  `users`.`encrypted_password` AS t0_r2, `users`.`password_salt` AS t0_r3,
  `users`.`remember_token` AS t0_r4, `users`.`created_at` AS t0_r5,

dpritchett

daniel@hubertus-bigend ~/s/order_contents> diff ./*
9,16c9,11
<     def add(variant, quantity = 1, currency = nil, shipment = nil)
<       line_item = add_to_line_item(variant, quantity, currency, shipment)
<       reload_totals
<       shipment.present? ? shipment.update_amounts : order.ensure_updated_shipments
<       PromotionHandler::Cart.new(order, line_item).activate
<       ItemAdjustments.new(line_item).update
<       reload_totals
<       line_item

dpritchett

Loading development environment (Rails 4.1.9)
Spree::Taxon.find(4966).self_and_descendants.to_sql #=> "SELECT `spree_taxons`.* FROM `spree_taxons`  WHERE (`spree_taxons`.`lft` >= 447) AND (`spree_taxons`.`lft` < 500)  ORDER BY `spree_taxons`.`lft`"
Loading development environment (Rails 4.2.0)
>> Spree::Taxon.roots[0].self_and_descendants.to_sql #=> "SELECT `spree_taxons`.* FROM `spree_taxons` WHERE (`spree_taxons`.`lft` < 500)" 

dpritchett

USE musiclender;

-- CREATE TABLE products_50k;
SELECT * FROM products_400k LIMIT 10000 INTO products_50k;
INSERT INTO products_50k SELECT * FROM products_400k LIMIT 10000 OFFSET 50000;
INSERT INTO products_50k SELECT * FROM products_400k LIMIT 10000 OFFSET 100000;
INSERT INTO products_50k SELECT * FROM products_400k LIMIT 10000 OFFSET 200000;
INSERT INTO products_50k SELECT * FROM products_400k LIMIT 10000 OFFSET 300000;

dpritchett

FROM rails:4.2.2                                                                 
MAINTAINER dpritchett@railsdog.com                                               
                                                                                 
# first pass of gem caching                                                      
RUN mkdir /webapp                                                                
ADD ./data/docker-gemcache/* /webapp/                                                                                     
                                                                                 
WORKDIR /webapp                                                                  
RUN bundle install -j4                                                           
                                                                                 

dpritchett

#!/usr/bin/env sh

# take the current folder name as the app name
APPNAME=${PWD##*/}

# start a new persistent postgres container named appname_pg that listens on local port 5432
docker run -p 5432:5432 --name ${APPNAME}_pg postgres

dpritchett

require "logger"

# build a persistent logger that we can send stuff to at will
def logger
  @_logger ||= Logger.new("nicole.log")
end

# sample command that would be hard to figure out if it wasn't logged
# note: this is going to die
def probably_broken_command

dpritchett

Rails.application.routes.draw do
  get '*path', :to => redirect('http://zombo.com')

  # all of your actual routes are still in place below
end

dpritchett

> git push -f heroku master
Fetching repository, done.
Counting objects: 5433, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (4627/4627), done.
Writing objects: 100% (5433/5433), 2.68 MiB | 231.00 KiB/s, done.
Total 5433 (delta 1711), reused 1773 (delta 501)

-----> Node.js app detected