shapr

# Edit this configuration file to define what should be installed on
# your system.  Help is available in the configuration.nix(5) man page
# and in the NixOS manual (accessible by running ‘nixos-help’).

{ config, pkgs, ... }:

{
  imports =
    [ # Include the results of the hardware scan.
      ./hardware-configuration.nix

shapr

[root@nixos:~]# nixos-rebuild switch
building Nix...
building the system configuration...
Warning: do not know how to make this configuration bootable; please enable a boot loader.
activating the configuration...
setting up /etc...
setting up tmpfiles

shapr

• dining philosophers problem - many threads accessing the same memory lead to problems like deadlock / livelock
• locks? hard to think about, don’t compose, priority inversion
  • thread-safe hash table doesn’t mean you can atomically move an entry from one hash table to another
• transactions in memory! ACI from ACID (memory isn’t durable)
• transactional memory does compose!
• but wait, rolling back a transaction can get really expensive, how is this a benefit?
  • only allowed to perform operations that can be rolled back / undone
  • Haskell already does this in the type system, non-issue there
• optimistic concurrency
  • no work completed while waiting for a lock

shapr

{-# LANGUAGE OverloadedStrings #-}
module Main where
import           Control.Applicative
import           Data.Attoparsec.Text hiding (take)
import           Data.Maybe
import           Data.Monoid
import qualified Data.Sequence as S
import qualified Data.Text.IO as TIO

main :: IO ()

shapr

# for long running commands
function try () {
    tally $* && fin || die; # cargo install tally, replacement for time
}

function play_sound () {
    aplay -N -q $HOME/.bin/$1.au
}

function fin () {

shapr

[alias]
	# Checkout a pull request branch on an upstream project. It
	# handles PRs that get rebased as well.
	#
	# git pr 3
	pr = "!f() { git checkout master; git branch -D pr/$1 || true; git fetch origin refs/pull/$1/head:pr/$1 && git checkout pr/$1; }; f"

	dpr = "!f() { git checkout develop; git branch -D pr/$1 || true; git fetch upstream refs/pull/$1/head:pr/$1 && git checkout pr/$1; }; f"

	pur = "!f() { git checkout master; git branch -D pr/$1 || true; git fetch upstream refs/pull/$1/head:pr/$1 && git checkout pr/$1; }; f"

shapr

{-# LANGUAGE OverloadedStrings #-}
module Main where

import Data.Text (Text)
import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import Data.Attoparsec.Text

main :: IO ()
main = do input <- TIO.readFile "input3.txt"

shapr

#+name: layout
#+RESULTS: layout-calc
| q | w | e | r | t | y | u | i | o | p |
|   | a | s | d | f | g | h | j | k |   |
|   | z | x | c | v | b | n | m |   |   |

#+name: layout-calc
#+BEGIN_SRC emacs-lisp :var table=layout
  (message table)
#+END_SRC

shapr

;; Added by Package.el.  This must come before configurations of
;; installed packages.  Don't delete this line.  If you don't want it,
;; just comment it out by adding a semicolon to the start of the line.
;; You may delete these explanatory comments.
(package-initialize)

;; make sure use-package is installed
(require 'package)
(add-to-list 'package-archives
	     '("melpa" . "https://melpa.org/packages/")

shapr

"""
Pablo buys popsicles for his friends.
The store sells single popsicles for$1 each, 3-popsicle boxes for$2, and 5-popsicle boxes for$3.
What is the greatest number of popsicles that Pablo can buy with$8?
"""
from z3 import *

box1pop, box3pop, box5pop =Ints('box1pop box3pop box5pop')
pop_total=Int('pop_total')
cost_total=Int('cost_total')