evanrinehart

function just(x){ return {just: x}; }
var nothing = {nothing: null};
function maybe(d, f, m){
  if('nothing' in m){
    return d;
  }
  else if('just' in m){
    return f(m.just);
  }
  else{

evanrinehart

(ns atomic-playground.sheets
  (:import [com.google.api.client.http GenericUrl]
           [com.google.api.services.drive.model File]
           [com.google.api.client.googleapis.auth.oauth2 GoogleCredential GoogleCredential$Builder]

           [com.google.api.client.http HttpTransport]
           [com.google.api.services.drive Drive Drive$Builder]

           [com.google.api.services.drive DriveScopes]

evanrinehart

{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE AllowAmbiguousTypes #-}
import Test.QuickCheck
import Control.Monad

{-
This defines a "continuous space" I and a continuous function from I to itself.
You can interpret this space as a really low resolution continuous line segment

It consists of 5 "open subspaces":

evanrinehart

// code is for 16MHz adafruit trinket (atmel ATtiny85)
int red   = 0;
int green = 1;
int blue  = 2;

void setup() {
  // put your setup code here, to run once:
  pinMode(red,   OUTPUT);
  pinMode(green, OUTPUT);
  pinMode(blue,  OUTPUT);

evanrinehart

module Foo where

import Data.Attoparsec.ByteString
import Data.Attoparsec.ByteString.Char8
import Data.Attoparsec.Combinator
import Control.Applicative
import Data.Time
import Data.ByteString
import qualified Data.ByteString as BS
import Control.Monad

evanrinehart

withShader :: ShType -> Src -> (GLuint -> IO (Either String a)) -> IO (Either String a)
withShader ty src action = mask $ \restore -> do
  eithv <- loadShader ty src
  case eithv of
    Left err -> return (Left err)
    Right v -> restore (action v) `finally` deleteShader v

evanrinehart

d/dt enemies = keep <> new <> gone where
  keep = mapWithKey (Ok . enemyAI) enemies
  new = on buttonA newK (Create newEnemy)
  gone = on buttonB target (Delete (enemies ! target))
  on but k act = unDelta (\d -> if d < 0 then singleton k act else mempty) (d/dt but)
  ks = keys enemies
  newK = maximum ks + 1

evanrinehart

d/dt x = v
d/dt v = a
a = -x

evanrinehart

Let's say you have these equations:
a = -x
d/dt v = a
d/dt x = v

x and v are state variables and their initial values are a free choice.
Let's say x = 1 and v = 0 are the chosen starting state.

According to Wolfram Alpha, the solution to these equations and these initial values is:
x(t) =  cos(t)

evanrinehart

/* The cord switch is attached to CORD_IN, and we're using internal pullups.
   so normally the value reads HIGH. when cord is pulled and connects to ground, reads LOW. */
/* In so many words, we're using the debounce protocol
   described at university of utah "debouncing.pdf" section "software debouncers" */
/* return 1 if cord pull is detected, else 0 */
/* If 1 is returned, it will only be returned once (until cord is released and cycled). */
#define DEBOUNCE_TIME 100
int debounceState = HIGH;
int debounceTimer = DEBOUNCE_TIME;
int checkCordIn() {