charles-cooper

Keybase proof

I hereby claim:

• I am charles-cooper on github.
• I am charlescooper (https://keybase.io/charlescooper) on keybase.
• I have a public key ASBc3MIg-ZmRXFd8_NXIsH6FfxvXAzpf8lEZLwVBNnf3mgo

To claim this, I am signing this object:

charles-cooper

QUERY PLAN                                                                                                                                                                                                                                                                                                                                        
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Nested Loop  (cost

charles-cooper

#!/bin/sh

# This script, intended to be run as a cron job, checks if there are any logins or recent logins and shuts down if there are none. It is not intended to be portable and was written on a Ubuntu 16.04 machine.

last_login_time=$(grep "systemd-logind" /var/log/auth.log | perl -pe "s/ ip.*//" | tail -1 | date --file=/dev/stdin +%s)

if [ $(($cur_time - $last_login_time)) -ge 3600 ] && [ $(who | wc -l) -eq 0 ]
then
  init 0
else

charles-cooper

# ~/.profile: executed by the command interpreter for login shells.
# This file is not read by bash(1), if ~/.bash_profile or ~/.bash_login
# exists.
# see /usr/share/doc/bash/examples/startup-files for examples.
# the files are located in the bash-doc package.

# the default umask is set in /etc/profile; for setting the umask
# for ssh logins, install and configure the libpam-umask package.
#umask 022

charles-cooper

module Main where

import System.Process
import Control.Concurrent

main :: IO ()
main = do
  (_, _, _, p) <- createProcess ((shell "sleep 1") { create_group = True })
  forkIO $ waitForProcess p >>= print
  threadDelay 10

charles-cooper

{-# LANGUAGE DeriveFunctor #-}

module Main where
import Data.Monoid
import Control.Comonad
import Data.Fix
import Data.Foldable as Foldable

newtype Cell a b = Cell { runCell :: Either () ((,) a b) } deriving (Functor)

charles-cooper

{-# LANGUAGE TypeFamilies, DataKinds, PolyKinds, TypeOperators #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# OPTIONS_GHC -fwarn-unticked-promoted-constructors #-}

import Prelude hiding (lookup)
import qualified Data.Map as Map

type family Equal a b :: Bool where
  Equal a a = 'True

charles-cooper

-- These are straightforward. Just map or zipWith all operations.
-- The only interesting one is fromInteger, typically when people
-- do an operation on a vector and a scalar, they mean to run it
-- over the vector. E.g. [1,2,3] * 1.

instance Num a => Num [a] where
  (+)          = zipWith (+)
  (*)          = zipWith (*)
  abs          = map abs
  signum       = map signum

charles-cooper

data Val a = Val Int deriving Show
instance Functor Val where
  fmap _ (Val x) = Val x
coerce :: Val a -> Val b
coerce = fmap undefined

data Void

x :: Val Int
x = Val 1

charles-cooper

$ cat turing.hs 

-- this is a finite memory tape with dereference and assign

import Control.Monad.State
import qualified Data.Map as Map
import Data.Word

type Ptr = Word64
-- a C-like array (char *) which maps int64 to int8