Ryan Frazier's Blog

Some COVID Numbers

Wed, 22 Dec 2021 15:29:06 -0700

The following is an email I wrote to the COVID response team at my workplace. I have since had many conversations with people and wanted to show them the research I have done and the numbers I could and, more importantly, could not find.

I have yet to hear a decent refutation of these numbers. The usual response is something like, "I trust the CDC and 3 years of data is good enough."

This email was written sometime around April/June of 2021 so some of the numbers are incomplete. Updated numbers as of today (Dec. 22, 2021) has not really changed my assessment.

[ EMAIL START ]

Hi COVID response team,

Thanks for your work. As engineers and scientists we are taught to be skeptical. I have therefore tried to dig around in the numbers I could find.

I found this paper written by 3 economists very interesting comparing mortality rates between Denmark, Finland, Norway, and Sweden https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3674138 (and a summary here https://www.aier.org/article/swedens-high-covid-death-rates-among-the-nordics-dry-tinder-and-other-important-factors/). They propose the dry tinder theory. The reason I find that interesting is that Sweden’s charts over the last several years look very similar to our own. We had a very mild flue season the last 2 years and then we were hit fairly hard by COVID.

Research that I would like to do but can’t find the numbers is to look at the last 150 years of mortality deaths and compare them. Most news bites and the CDC (https://www.cdc.gov/nchs/nvss/vsrr/covid19/excess_deaths.htm see chart below) seem to only show the public what has happened in the last 4 years which feels very misleading to me because I’m not sure how you can draw an accurate trendline based on 4 years of data. You should be looking at 100+ years. If you are going to make the claim that this is worse or comparable to the Spanish Flu then I need some numbers to back those claims.

COVID19 Excess Deaths. source https://www.cdc.gov/nchs/nvss/vsrr/covid19/excess_deaths.htm accessed Sept. 2021

I did my best by going to data.gov and plotting all mortality numbers by week. The best I could do was go back to 2014. Sources:

https://catalog.data.gov/dataset/weekly-counts-of-deaths-by-state-and-select-causes-2014-2018 https://catalog.data.gov/dataset/weekly-counts-of-deaths-by-state-and-select-causes-2019-2020

I combined the data into one spreadsheet which I have attached.

US deaths from all causes generated from data.gov data

If we slice each year by the mortality valley, which appears to be around August I made the following table.

Aug-July	Total	% Change
2014-2015	2,699,118
2015-2016	2,692,140	-0.00259
2016-2017	2,783,134	0.0338
0.018689018	2,835,147	0.018689
2018-2019	2,823,934	0.108804
2019-2020*	1,571,180
average	2,827,443

*Short 7+ months due to insufficient data

The US life expectancy curve has flattened in the last 5 years, so it would stand to reason that total mortality rates would also increase. It seems that if the life expectancy has gone down and death rates haven’t increased then we were ripe for a disease to come through and bring the numbers back up to the trend line. Source: https://www.macrotrends.net/countries/USA/united-states/life-expectancy (filter the years between 1950 and 2019)

US life expectancy source https://www.macrotrends.net/countries/USA/united-states/life-expectancy

So the most I can say about this data is that there is definitely a spike, but it is only the worst since 2014 because I don’t have the data. I would really like a comparison to the swine flu, SARS, Spanish flu, all in one graph. Is this a 1 in 10 year disease, 1 in 25, 1 in 100?

What I would like to see is a chart like the one I was able to gather about Sweden. Source: https://www.scb.se/en/finding-statistics/statistics-by-subject-area/population/population-composition/population-statistics/pong/tables-and-graphs/yearly-statistics--the-whole-country/population-and-population-changes/ I have also attached the spreadsheet with my chart in it.

Sweden Total Deaths 1850-2019 generated from scb.se data

You can indeed find the catastrophic spike from the 1918 Spanish Flu. I replicated this based on a graphic I saw on a podcast. It has more annotations and a bit more detail but I was able to reproduce it pretty close so I trust it. Source: https://youtu.be/3BEfkKCXSOQ around 39:19

Labeled Sweden deaths from podcast

I don’t have the week by week data but Sweden has a precipitous drop off in 2019 which probably account for the bad COVID spike.

Sweden Deaths/Population 2014-2019 from scb.se data

Here is a comparison with the US for those same years. I didn’t have the total population, but this chart would slope downward if it did. It looks very similar. We had less deaths in 2018 than 2014 with more people to draw from. There is a huge cliff in deaths in the years 2018 to 2019.

US Deaths/Population 2014-2019 from data.gov data

I’m trying to go to the original source because if you play with the numbers long enough you can tell any story you want. I suppose the purpose of this email is to question if the hysteria is actually warranted. I am having difficulty coming up with the data to support the hysteria (e.g. lockdowns, mandatory masks, …). It seems we have forgotten all we know about virus transmission from the last hundred years in favor of a myopic view of the last 4 years.

Help finding the US total mortality numbers for the last 100+ years would be much appreciated.

[ EMAIL END ]

Microbit Asteroids

Tue, 21 Dec 2021 14:24:22 -0700

We will be using the Mu Editor.

Here is the final version of this simple game.

Your browser does not support this video.

Here is our plan of attack.

create controllable rocket
make asteroid fall from the sky
check if game over (asteroid collides with our rocket)

TLDR;

Go to the bottom and copy and paste my code into your microbit.

Light up an LED

First we need to know how to light up individual lights on the 5x5 grid. We can use the function display.set_pixel(x,y,b).

from microbit import *
display.set_pixel(0,0,9)

Lighting LED 0,0 on the grid

The LED grid

The 5x5 grid can be addressed with the cartesian coordinates with the origin starting at the top left.

The LED cartesian grid start at the top right

As an exercise try to light up each of the four corners of the grid.

What happens if you try to light up an LED that isn't on the grid like (0,5)?

Button Input

We are going to need to control our rocket with the A and B buttons. So let's make a simple program where a pixel lights up if we just push a button.

from microbit import *
if button_a.is_pressed():
display.set_pixel(0,0,9)

The LED cartesian grid start at the top right

Now if you run this you likely won't see anything happen. This is because the code is only run once. What we actually want to happen is for the microbit to keep checking if we have pushed a button and then respond to it. So we really need the code to always be running our code. The way we do that is with an event loop.

We also need to tell the microbit to turn the light off if we are not pushing the button. We'll use display.clear(). Otherwise once the light is turned on it will stay on whether we press the button again or not.

from microbit import *
# event loop hack
while True:
if button_a.is_pressed():
display.set_pixel(0,0,9)
else:
display.clear()

Making our rocket

Now we need to be able to control our rocket (the pixel) with the buttons. We want our rocket to be on the bottom so the available positions of our rocket will be (0,4), (1,4), (2,4), (3,4), and (4,4).

If you'll notice the Y position stays the same and the X position moves. So we should make a variable in our code for the part that changes. We'll combine what we know about checking for buttons and drawing pixels to the grid.

from microbit import *
# this part changes based on button pushes
rocketX = 0
# this doesn't change
rocketY = 4
while True:
if button_a.is_pressed():
# move the rocket to the left by 1
rocketX = rocketX - 1
if button_b.is_pressed():
# move the rocket to the right by 1
rocketX = rocketX + 1
# draw the rocket
display.clear()
display.set_pixel(rocketX,rocketY,9)

The program kind of works but it has some problems. Can you find them? There are 2.

Problem 1

The program runs really fast so when we push a button our rocket shoots of the screen and then there is an error. We can fix this by slowing down our event loop with the sleep function. Since we are only checking the buttons every so often now we should switch to checking if there have been any button presses with button_a.get_presses()

from microbit import *
rocketX = 0
rocketY = 4
while True:
sleep(200)
if button_a.get_presses():
rocketX = rocketX - 1
if button_b.get_presses():
rocketX = rocketX + 1
display.clear()
display.set_pixel(rocketX,rocketY,9)

Problem 2

Ok. So we've fixed that but we can still run our rocket off the screen.

Your browser does not support this video.

We need a way to make sure that you can't move your rocket off the screen and crash our program. In order to do that we need to guarantee that rocketX is never greater than 4 or less than 0.

from microbit import *
rocketX = 0
rocketY = 4
while True:
sleep(200)
if button_a.get_presses() and rocketX > 0:
rocketX = rocketX - 1
if button_b.get_presses() and rocketX < 4:
rocketX = rocketX + 1
display.clear()
display.set_pixel(rocketX,rocketY,9)

Your browser does not support this video.

Asteroids

Now that we have a controllable rocket we need some asteroids to dodge.

The idea is that an asteroid will start at a random place on the top and fall towards the bottom.

Try to draw a random pixel to the screen.

from microbit import *
from random import randint
rocketX = 0
rocketY = 4
asteroidX = randint(0, 4)
asteroidY = 0
while True:
sleep(200)
if button_a.get_presses() and rocketX > 0:
rocketX = rocketX - 1
if button_b.get_presses() and rocketX < 4:
rocketX = rocketX + 1
display.clear()
display.set_pixel(rocketX, rocketY, 9)
# draw the asteroid
display.set_pixel(asteroidX, asteroidY, 9)

Try reseting the microbit several times with the button on the back and notice how the asteroid starts at different positions.

Now we need the asteroid to fall down and then when it goes off the screen start over at the top again. We also need to make sure that the asteroid doesn't try to draw off screen or our program will crash just like our rocket crashed our program before.

from microbit import *
from random import randint
rocketX = 0
rocketY = 4
asteroidX = randint(0, 4)
asteroidY = 0
while True:
sleep(200)
if button_a.get_presses() and rocketX > 0:
rocketX = rocketX - 1
if button_b.get_presses() and rocketX < 4:
rocketX = rocketX + 1
if asteroidY < 4:
asteroidY = asteroidY + 1
else:
# reset the asteroid
asteroidY = 0
asteroidX = randint(0,4)
display.clear()
display.set_pixel(rocketX, rocketY, 9)
display.set_pixel(asteroidX, asteroidY, 9)

You'll notice now that we almost have a working game. We now need to detect if the asteroid crashed into your rocket.

Game Over

To do that we need to check if the asteroid is occupying the same space as our rocket.

from microbit import *
from random import randint
rocketX = 0
rocketY = 4
asteroidX = randint(0, 4)
asteroidY = 0
while True:
sleep(200)
if button_a.get_presses() and rocketX > 0:
rocketX = rocketX - 1
if button_b.get_presses() and rocketX < 4:
rocketX = rocketX + 1
if asteroidY < 4:
asteroidY = asteroidY + 1
else:
asteroidY = 0
asteroidX = randint(0,4)
# check the game over condition
if asteroidX == rocketX and asteroidY == rocketY:
display.scroll('GAME OVER')
else:
display.clear()
display.set_pixel(rocketX, rocketY, 9)
display.set_pixel(asteroidX, asteroidY, 9)

Bonus

There are a bunch of other features you could add to this game. Here are some ideas.

connect up a speaker and make music/sound on asteroid collision
keep score (either a timer or number of asteroids missed)
add multiple asteroids
allow the rocket to shoot with A+B button presses
use the microbit internal tilt sensor to control the rocket

Add sound

Microbit verion 2 has better support for sounds, I only have version 1 so I'll make due with playing some music on game over.

import music
...
# check the game over condition
if asteroidX == rocketX and asteroidY == rocketY:
music.play(music.BADDY)
display.scroll('GAME OVER')

Keep Score

To keep score we'll count the asteroids that go by. For this we need another variable to count the asteroids.

score = 0
while True:
...
if asteroidX == rocketX and asteroidY == rocketY:
# report the score to the player
display.scroll('GAME OVER! SCORE: ' + score)
# reset the score on game over
score = 0
else:
score = score + 1
display.clear()
display.set_pixel(rocketX, rocketY, 9)
display.set_pixel(asteroidX, asteroidY, 9)

Multiple Asteroids

Multiple asteroids becomes trickier because we don't just want to copy and paste the asteroid code and keep track of all those variables. We need a way to abstract out the idea of an asteroid. We'll use a class. This is a more advanced topic so beware.

from microbit import *
import music
from random import randint
# base class
class Point:
x = 0
y = 0
brightness = 9
def update(self):
pass
def draw(self):
display.set_pixel(self.x, self.y, self.brightness)
def __eq__(self, other):
return self.x == other.x and self.y == other.y
class Rocket(Point):
brightness = 9
def __init__(self):
self.x = 2
self.y = 4
def update(self):
if button_a.get_presses() and self.x > 0:
self.x -= 1
if button_b.get_presses() and self.x < 4:
self.x += 1
class Asteroid(Point):
def __init__(self):
self.brightness = randint(3, 7)
self.x = randint(0, 4)
self.y = 0
def update(self):
if self.y < 4:
self.brightness += randint(-2, 2)
if self.brightness > 9:
self.brightness = 9
if self.brightness < 2:
self.brightness = 2
self.y += 1
else:
self.__init__()
def init():
global rocket
global asteroids
global counter
global num_asteroids
global speed
rocket = Rocket()
asteroids = []
counter = 0
num_asteroids = 1
speed = 200
init()
while True:
# throttle the event loop
sleep(speed)
counter += 1
# gradually add more asteroids
if counter % 2 == 0 and len(asteroids) < num_asteroids:
asteroids.append(Asteroid())
if counter % 3 == 0 and len(asteroids) < num_asteroids:
asteroids.append(Asteroid())
# difficulty adjustment
if counter > 13:
num_asteroids = 2
if counter > 37:
num_asteroids = 3
if counter > 53:
speed = 170
if counter > 71:
speed = 150
if counter > 93:
speed = 120
if counter > 111:
num_asteroids = 4
rocket.update()
[x.update() for x in asteroids]
# check the game over condition
if True in [rocket == x for x in asteroids]:
display.show(Image.ANGRY)
music.play(music.BADDY)
display.scroll(str(counter))
# reset the game variables
init()
else:
display.clear()
rocket.draw()
[x.draw() for x in asteroids]

What Is Functional Programming

Tue, 20 Oct 2020 09:55:15 -0600

In my day to day work as a software engineer I do not have the luxury of using a functional language like Haskell or Elm, however I have learned a lot from Elm that has changed how I program in JavaScript or Python. Here is a run-down of some of the concepts I have learned from writing 3000+ lines of Elm code.

Here are some of my projects written entirely in Elm.

Know Your Theory - a music theory drill app
Elm Piano Teacher - a midi keyboard interactive tool
Music Scale Explorer - interactive graph of musical scales
Circle of 5ths Explorer - interactive circle of 5ths with key signatures and keyboard
Uke Chord Finder - interactive Ukulele chord finder

FP Vocabulary

Here is a list of common terms that come up when learning functional programming (FP). I will discuss many of them in this article.

Pure Function
Side Effect
Referential Transparency
Mutable/Immutable
Currying
Monad
Algebraic Data Types
Variant
Lambda Calculus

Pure Functions

What is a pure function?

A function is said to be pure if 1) given the same arguments it always returns the same result and 2) the function has no side effects.

function add(a,b) {
return a + b;
}
function impureAdd(a,b) {
return a + b + c;
}
console.log(add(1,2)) // 3
// console.log(impureAdd(1,2)) // EXPLOSION!!!
c = 1
console.log(impureAdd(1,2)) // 4
c = 2
console.log(impureAdd(1,2)) // 5

What is a side effect?

A side effect is something that occurs as a result of a function call that does not get returned from the function.

Referential Transparency

An expression is said to be referentially transparent if the evaluation of the function can be replaced with its return value and not effect the program's behavior.

result = add(2,3) + 5 // result == 10
result = 5 + 5 // result == 10

By contrast, if the function call cannot be replaced by the output then the function is said to be referentially opaque.

No For Loops?

In a pure functional language like Haskell or Elm, you will notice there are no for loops. You must process all lists with map, reduce, and filter (among others).

list = [1,2,3,4]
// Imperative
listTimesThree = []
for(i = 0; i < list.length; i++) {
listTimesThree.push(list[i] * 3)
}
// Declarative
listTimesThree = list.map(x => x * 3)

What are all the things that could go wrong in a for loop?

mental burden of parsing a for loop (What does it do? Is it correct?)
thread mutate the processing list
mutate the iterator variable i
out of range list access

Currying

currying is the technique of converting a function that takes multiple arguments into a sequence of functions that each take a single argument.

Wikipedia Currying

add = a => b => a + b
addOne = add(1) // What does this return?

add(1)(2) // 3

list.map(x => addOne(x)) // [2,3,4,5]

How is currying useful?

How about providing different ways to render a list? Currying makes it easy to make functions from other functions.

list = ['Fries', 'Hamburger', 'Shake']
latexListHead = x => `\\begin\{itemize\}\n${x}\n\\end\{itemize\}`
latexItem = x => `\\item ${x}`
htmlListHead = x => `<ul>\n${x}\n</ul>`
htmlItem = x => `<li>${x}</li>`
mdListHead = x => x // The identity function
mdItem = x => `- ${x}`
renderList = headFn => itemFn => list => headFn(list.map(x => itemFn(x)).join('\n'))
latexList = renderList(latexListHead)(latexItem) // LaTeX render function
webList = renderList(htmlListHead)(htmlItem) // HTML render function
mdList = renderList(mdListHead)(mdItem) // Markdown render function

console.log(webList(list))
console.log(latexList(list))
console.log(mdList(list))

Now what if you wanted several styles of lists, like a fancy web list.

htmlListHead = classes => x => `<ul class='${classes.join(' ')}'>\n${x}\n</ul>`
bigBlueListHead = htmlListHead(['big', 'blue'])
smallRedListHead = htmlListHead(['small', 'red'])
webList = renderList(bigBlueListHead)(htmlItem)
console.log(webList(list))

There are other uses for currying like generating a range of math plots. See my post on creating beautiful math homework. And here is the python file

Exception Throwing is a Side Effect

The reasoning is that I consider exceptions to be no better than “goto’s”, considered harmful since the 1960s, in that they create an abrupt jump from one point of code to another. In fact they are significantly worse than goto’s

They are invisible in the source code.

They create too many possible exit points for a function.

Joel Spolsky at Joel on Software

I wrote about this topic in a previous blog post Exceptions Considered Harmful.

JavaScript helper libraries

JavaScript is notorious for an inconstant API. What functions are immutable? For example, map() creates a new array whereas sort() and reverse() mutate the array in place and returns the mutated array. This inconsistency is a mental burden. Therefore there is a need for libraries like Ramda.

list = [4,2,3,1]
sortedList = list.sort()
console.log(list) // [4,2,3,1] or [1,2,3,4]?

Compare with Ramda's sort.

JS Libraries

TypeScript Libraries

Other Resources

My Side Projects

Thu, 13 Aug 2020 00:00:00 +0000

KnowYourTheory

The app: https://knowyourtheory.com

This is the music learning platform I have been working on since fall of 2018. The front end is all in Elm.

I gave a talk at Elm Conf 2019 about how I built this app.

I am currently working and planning out the backend. My current plan is the following:

netlify identity for authorization and authentication
PouchDB/CouchDB for storing user data using IBM's cloudant
netlify functions for glueing everything together

And here are some of my ideas for my next features.

Frazier Piano Studio

This is my piano teaching website https://frazierpianostudio.com. I post my teaching resources and blog a little bit.

I also put up my coding music experiments and visualizations on this site. Here are some of them.

Music Scale Explorer

Circle of Fifths Explorer

Elm Piano Teacher

This little app is built in Elm to demonstrate music concepts for my Elm Conf 2019 talk.

You will need a midi keyboard plugged into your computer and use a browser, like Chrome, that supports the web midi api.

I needed an audio and visual way to talk about music stuffs with a keyboard. It uses the WebMIDI api available in Chrome. It also uses a lot of the tooling like note and keyboard rendering I have built up for knowyourtheory.com.

The things I added were

sound with Tone.js
midi with WebMidi.js

I then added decoders and encoders for all the midi messages so I could handle everything else in Elm.

Lilypond in Markdown

This projects generates music SVG from a markdown file using GNU Lilypond. I made a custom Nunjucks tag to process the markup and inject Lilypond's SVG output into the resulting HTML file.

More about the process can be found in this blog post

I also extended this to generate music files and play them in the browser using the output MIDI from Lilypond.

It uses

LilyPond markup and compiler to generate music SVG
TiMidity++ to transform the midi files
FFmpeg to process the audio for the web
Howler.js to manage the audio in the browser

I then stitch all the sound and audio stuff together using vanilla JavaScript.

Popcorn Cove Subscriptions

I built an app to help manage subscription boxes for a popcorn candy store my sister and brother-in-law run in Washington.

GitHub: https://github.com/pianomanfrazier/popcorncove_subscriptions

The app is built with the following

deployed on Heroku
python flask
PostgresDB
VueJS with Vuetify for the UI

Lemmings Clone

GitHub: https://github.com/pianomanfrazier/lemmings-clone

I built this for my game development class in vanilla javascript. It uses no game engine so we had to program the game loop ourselves. I learned a lot about sprite sheets and managing game state.

The levels that you see in the game were described in CSV. My goal for this was to have users be able to create their own levels and upload them. I never got that far.

Dr Doug's Pediatrics

The website: https://drdougspediatrics.com/

This was my first freelance web project. My kid's dentist's old website was broken for mobile so I built them a new website.

The dependecies are really minimal for this project. I didn't use a framework. I stitched together some things to make it work.

Tachyons for the CSS
Swiper.js for mobile image swipers
Zepto because I was into JQuery at the time and wanted something lighter
particles.js for the bubble effect on the landing splash image

Introduction to Algebraic Data Types

Tue, 14 Jul 2020 00:00:00 +0000

The demo code:

Elm on ellie-app
TypeScript on TypeScript playground

One of the concepts in functional programming that trips up beginners is Algebraic Data Types (ADT). I am going to go through some examples and relate it to some concepts that would be familiar to Object Oriented Programming (OOP).

For this introduction I will be using TypeScript for the OOP examples and Elm for the functional examples.

Let's start with an example.

type Animal = Cat | Dog

An Animal can be either a Cat or a Dog, but you can't just be an animal. You need to be a type of an animal, the classic "is a" relationship. This is a bit similar to abstract classes in OOP languages.

abstract class Animal {
abstract speak(): string;
}
class Cat extends Animal {
speak(): string {
return "meow";
}
}
class Dog extends Animal {
speak(): string {
return "bark";
}
}
// can't make an abstract Animal
// const myAnimal = new Animal();
const myCat = new Cat();
console.log(myCat.speak());

Now you could make a function that generically takes any type of Animal as an argument.

function feedAnimal(animal: Animal): string {
return "thanks for the food! " + animal.speak();
}
console.log(feedAnimal(myCat));

Similarly, let's translate this to Elm.

animalSpeak : Animal -> string
animalSpeak animal =
case animal of
Cat ->
"meow"
Dog ->
"bark"

feedAnimal : Animal -> string
feedAnimal animal =
"thanks for the food! " ++ animalSpeak(animal)

Why are they useful?

Easier refactors. You can catch problems at compile time.
Can constrain the problem domain by the type system. See Making Impossible States Impossible.

When working on a new feature or a refactor with a strongly typed language I will often start by changing the data structures and then let the compiler tell me where my code fails to compile. When my code compiles again my job is mostly done.

You can do this by leveraging classes and using them as types but it is a lot easier and compact to have a robust type system built into the language. There is usually a lot of boiler code needed to get some better type safety in languages like Java or TypeScript. See this stackoverflow question.

Animal Names

Since there are no classes or member variables in a language like Elm we use records instead.

type alias AnimalRecord =
{ type_ : Animal
, name : String
}
felix = AnimalRecord Cat "Felix"

When I write TypeScript I actually prefer using interfaces instead of defining classes. The reason for this preference is that I like to separate the structure of the data from the operations on that data.

I will, in fact, claim that the difference between a bad programmer and a good one is whether he considers his code or his data structures more important. Bad programmers worry about the code. Good programmers worry about data structures and their relationships.

Linux Torvalds, see https://lwn.net/Articles/193245/

So it would look like this:

interface AnimalRecord {
type_ : Animal;
name : string;
}
const felix : AnimalRecord = {
type_: new Cat(),
name : "Felix",
};

Immutability

One core idea of functional programming is immutability. You can get more immutability in TypeScript by declaring class members or interfaces as immutable.

for classes https://www.typescriptlang.org/docs/handbook/classes.html#readonly-modifier
for interfaces https://www.typescriptlang.org/docs/handbook/utility-types.html#readonlyt

An example with error handling

I wrote about this in another post Exceptions considered harmful.

Let's use the Either type from purify-ts to deal with errors in our code. The TypeScript compiler can help us if we give it the right information.

Below is the type signature for Either (almost). See https://github.com/gigobyte/purify/blob/master/src/Either.ts#L3 Neverthrow's Result type signature is a bit easier to read but has less functionality.

type Either<E, T> = Left<E, T> | Right<T, E>

An Either can be one of Left which holds the error or it can be Right which holds the successful return value.

// might be one of an Error or a result string
function getUsernameFromDB(id : number) : Either<Error, string> {
const username : string;
const error : Error;
try {
username = DB.getUserById(id);
} catch(e) {
error = e;
}
if (error) {
return Left(error); // error values are always Left
 } else {
return Right(username); // Right is "right" or the correct value
 }
// could use Either.encase instead
 // see https://gigobyte.github.io/purify/adts/Either#encase
 // return Either.encase(() => DB.getUserByID(id));
}
const result = getUsernameFromDB(1);
// now the compiler forces you to deal with the error
result.caseOf({
Left: error => error.toString(),
Right: value => value,
})

Here are the docs of caseOf statements for

When I first encountered ADT in Elm it looked so foreign. Once I got used to them I wished that every language I used had them. The compiler now becomes your best friend.

You can get fancier with TypeScript that I did in this post to get something closer to Elms ADTs using union types. See https://www.typescriptlang.org/docs/handbook/advanced-types.html#union-types TypeScript also has type guards that aid in handling these types.

My First 5 Day Fast

Fri, 10 Jul 2020 00:00:00 +0000

My experience with fasting

In my faith as a member of The Church of Jesus Christ of Latter-Day Saints we fast once a month. This is a 24 hour fast of no water and no food, commonly known as a black fast or a Jewish fast. I have been doing this monthly fast since I was about 8 years old. We then donate the money we saved on food and contribute to a fund to help the poor and needy. See Gospel Topics - Fast, Fasting.

A couple of years ago I started experimenting with intermittent fasting and extended fasting. My intermittent fasting routine now is either eat one meal a day (OMAD) or eat my first meal around 2-3 and dinner around 6. I will usually do OMAD for 2 or 3 days a week. Sometimes I cheat and eat Sunday breakfast, but that is my usual routine.

Once a month I usually do a longer 2-3 day fast. Because once a month my faith does a one day fast as a group, I don't really feel it much of a sacrifice to do a 24 hour fast anymore so I do at least 2 days. I'm not trying to compete with those around me, I just don't feel it much of a sacrifice. I might have already done 3 or 4 OMAD days earlier that week.

The purpose of the extended fast

I am already pretty lean so my purpose in fasting is not to lose weight.

There are many benefits to extended fasting such as increased mental clarity, autophagy, cancer prevention, and more. See Dr. Fung's amazing work The Complete Guide to Fasting. You can also find him on YouTube.

Fasting is an ancient practice. You can read about extended fasts in the bible. We have accounts of Jesus, Moses, and Elijah fasting for 40 days.

And he [Moses] was there with the Lord forty days and forty nights; he did neither eat bread, nor drink water. And he wrote upon the tables the words of the covenant, the ten commandments.

KJV Bible, Exodus 34:28

And he [Elijah] arose, and did eat and drink, and went in the strength of that meat forty days and forty nights unto Horeb the mount of God.

KJV Bible, 1 Kings 19:8

Then Jesus was led by the Spirit into the wilderness ... After fasting forty days and forty nights, He was hungry.

KJV Bible, Mathew 4:2

In Judaism the number 40 has some significance, so they probably didn't actually fast for a full 40 days. But I'm sure it was longer than 1 day. The number 40 occurs a lot in the Bible.

See scripture search "forty days", Wikipedia 40 Number - Judaism, and also Ask the Rabbi - The Number 40.

Preparation

I had been thinking about trying a 5 day fast, so last few weeks I have not been doing my daily fasts like I usually do. I also tried to up some of my portions. I've tried in the past to do 5 days but I get to the 3 day mark and feel like I need to end the fast.

The only thing I had on this fast other than tap water was sea salt and a bit of lemon juice. See my version of ketorade recipe.

Day 1 - Sunday July 5, 2020

Like I said earlier I am very comfortable doing one meal a day. I have built up to doing OMAD for the last few years.

Day 1 felt about like a normal day, although I don't usually go to bed hungry.

Day 2 - Monday July 6, 2020

Surprisingly, day 2 was the hardest day of the fast. I felt tired and my brain was pretty foggy. It was a bit hard to concentrate at work.

Another thing I noticed was that occasionally my heart would race. My pulse would increase to around 90 bpm. This is actually pretty common for me for a day 2 or 3 fast. My problem might be dehydration which I talk more about in days 3 and 4 of this post.

I did take some pink Himalayan salt and a bit of lemon juice mixed with water. That seemed to help a bit.

By the end of the day I was feeling a lot better and not sluggish and foggy. I went to bed at my normal time around midnight.

Day 3 - Tuesday July 7, 2020

I woke up a bit earlier than usual feeling very refreshed around 6:30 a.m. I went for an hour morning walk. I usually go on a half hour walk every morning. I was feeling great so I went a bit longer than usual.

At this point in the fast I started feeling really great. I had a lot of mental clarity and was really productive throughout the day.

I wasn't even that hungry anymore. I did occasionally have the desire to eat because I saw what the rest of my family was eating, but I didn't really feel hungry.

It made me think of my relationship with food. Sometimes I eat because I want to eat as entertainment or eat to be social, which is different than the body saying I need to eat. I feel like I didn't learn what true hunger was until I had done several 3 day fasts.

I felt especially more light headed than day 2. From what I've read is that the body sheds salt as it burns through your glycogen stores. At this point I was probably well into full ketosis.

On breaks from work (I work at home due to COVID 19 quarantine) I would go outside and weed my garden. When I would stand up I got really light headed. I figured eventually my body would adjust so I pushed through.

I had a lot of energy and stayed up a bit later than usual and went to bed around 12:45 a.m.

Day 4 - Wednesday July 8, 2020

I woke up again a bit before my 7 o'clock alarm and felt pretty good. I notice that I sleep really well on a fast and that I need less sleep than usual.

I felt a bit dehydrated although my pee was pretty clear. I drank a big glass of ketorade (lemon juice, lime juice, pink Himalayan salt) and then went for an hour walk.

I was not really that hungry although I felt like I was moving a bit slow.

I did get a metallic taste on the roof of my mouth on and off throughout the day.

The first couple of times I did a fast longer than 2 days I would get a strong metal mouth taste, especially in the mornings. I have done this enough times now that I rarely get metal mouth anymore.

I was again experiencing a lot of light headedness so I did some reading online and most people suggested take in more salt to retain more water. I think I was a bit dehydrated and my blood pressure was low. So I mixed up 1 teaspoon of sea salt in about 2 cups of water and drank that.

T.M.I. alert! Be careful not to overdo the salt because it will flush out your bowels. I didn't know salt water had this effect. The salt water flush (SFW) is part of The Master Cleanse.

Anyway I confirmed that my bowels were indeed empty.

I felt much better after the salt and I could sit and stand without feeling light headed.

I again went to bed late around 12:45 a.m.

Day 5 - Thursday July 9, 2020

Considering I went to bed late I did not expect to be done sleeping around 5:45 a.m. I felt fully refreshed and I didn't get drowsy throughout the day.

Again I had a large glass of ketorade.

I had some extra time in the morning so I went for a hike in the mountains before work. Where I live I have access to two canyons full of trails about a 5 min drive away.

I went on an hour and a half long hike. I had plenty of energy, although I was a bit winded more than usual going up the first hill of that hike.

I felt really great the rest of the day. I felt like I could have taken the fast a couple more days. I am already quite lean and I don't want to waste away so I am only going to day 5. I was surprised how good I felt.

Breaking the fast

For me one of the hardest parts of fasting is breaking the fast properly. Choosing not to eat is pretty simple. Not always easy but really simple. When you go back into eating food it's really tempting to just eat until you can't eat anymore.

For a 1 or 2 day fast I haven't had too many troubles just eating dinner like normal, but for anything longer than that I have had to be more careful. The digestive system shuts down and needs a bit of time to get going again.

If I do too much too fast I experience lots of intestinal distress like bloating and diarrhea and I often don't sleep very well that night.

So it is a good idea to have a plan when breaking your fast. Plan out what you will eat, how much, and when.

First meal

I broke my fast with a small meal around 4:00 p.m.

a small bowl of fermented asparagus
small handful of raw almonds and walnuts
bowl of fresh chicken broth with boiled onions and garlic (I just made some boiled shredded chicken for dinner)
1 slice of Dubliner cheese (my favorite cheese)
watermelon (1-2 Cups)

Watermelon is like cheating coming off a fast. It is mostly water but you feel like you have eaten a lot. It is pretty low carb so it will not spike your insulin (as much). I haven't tried it but you could probably gorge yourself on watermelon without any adverse effects.

A note about fermented foods. I have found coming off the fast I do especially well when I can eat something fermented. When you fast and the digestive system shuts down and I surmise that a lot of the gut flora also decreases. When you eat fermented foods at the break of the fast you replenish the gut with new bacteria.

I love fermenting vegetables. I have fermented jalapeños, carrots, onions, garlic, Brussels sprouts, cabbage (Saurekraut) and of course cucumbers. They are all yummy. My kids also like most of it too.

Second meal

The 4 o'clock meal settled really well so I had a somewhat normal portioned dinner around 7 o'clock. We had a picnic at the park. I tried to keep the carbs really low so I skipped the bread or any tortilla chips. We had fresh made chicken salad sandwiches. My wife even made fresh rolls (she is a master bread maker). So I had the sandwich without the bread 😞.

Chicken Salad -- shredded chicken, mayo, home made yogurt (no sugar added, extra cream added), dill pickles, a few raisins, course ground mustard, walnuts
cheddar cheese
tomato
greens (Spring mix)

This meal might not have been strictly keto, but it was pretty close (I probably had a total of 8 raisins in the chicken salad). I slept really well that night and I felt great the next morning.

Eating a keto-like diet coming off the fast keeps your insulin low and eases your body back out of the fast. My rule is to avoid breads, chips, cookies and the like. I choose instead a small portion of meat, cheese, any vegetable.

The day after breaking the fast

Beware not to overdo it the next day as well. I have experienced some gut problems the next day if I eat too much or a bunch of junk. I had a bunch of kettle corn the second day after a fast one year on July 24^th (Pioneer Day in Utah) and my guts were not very happy.

I try to get back on my normal eating routine the day after I break the fast. I don't try to make up for the lost weight immediately.

Case Statement in Typescript

Wed, 24 Jun 2020 12:33:03 -0600

One of my favorite features of functional languages like Elm is pattern matching. Here is an example:

type State
= Loading
| Error
| Ok
stateToString : State -> String
stateToString state =
case state of
Loading ->
"Loading ..."
Error ->
"Something went wrong."
Ok ->
"It's all good"

I found a simple way to provide an action for every case of a TypeScript enum.

enum State {
Loading,
Error,
Ok,
}
const STATE_MAP = {
[State.Loading] : () => "Loading ...",
[State.Error] : () => "Something went wrong.",
[State.Ok] : () => "It's all good",
}
function stateToString(state : State) : string {
return STATE_MAP[state]();
}

Link to TypeScript playground

Usually TypeScript won't allow bracket notation to access properties of an object. In this case the compiler knows that all cases of State are accounted for and can thus be used to index into the object.

Try removing one of the states from STATE_MAP and the TypeScript compiler will yell at you.

Element implicitly has an 'any' type because expression of type 'State' can't be used to index type '{ 0: () => string; 1: () => string; }'.
Property '[State.Ok]' does not exist on type '{ 0: () => string; 1: () => string; }'.

Exceptions Considered Harmful

Fri, 05 Jun 2020 13:32:21 -0600

The reasoning is that I consider exceptions to be no better than “goto’s”, considered harmful since the 1960s, in that they create an abrupt jump from one point of code to another. In fact they are significantly worse than goto’s

They are invisible in the source code.

They create too many possible exit points for a function.

Joel Spolsky at Joel on Software

How do we deal with uncertainty in our code?

If something goes wrong in our code we need to know about it, preferably without crashing our program. When I come back to the code months later or I am using someone elses code I want the compiler to help me handle errors gracefully.

Here are several patterns that I have seen, my own code included.

Pattern 1 - return true or false

function doWork() : boolean {
// do some SIDE EFFECT
 let result = doWork();
this.some_member_variable = result;
let success = result !== null;
if (success) {
return true;
} else {
return false;
}
}

Side effect's make it harder to reason about what your code does. Pure functions, side effect free functions, are also easier to test. Also if there was a failure you can't send a message to the function caller.

Pattern 2 - return null if failed

In the next examples, let's assume that our database stuff are synchronous to make things a bit simpler.

Instead of returning true or false we could return the value or a null value.

import DB from 'my-synchronous-database';
function getUser(id : UserID) : User | null {
const user = DB.getUserById(id);
if (user) {
return user;
} else {
return null;
}
}

This is slightly better, now that we don't have a side effect. However we still have no error message and we better make sure to handle that returned null value or our program will explode.

This eliminates the side effect but now creates a new problem.

I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W). My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler. But I couldn't resist the temptation to put in a null reference, simply because it was so easy to implement. This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years.

Tony Hoare at QCon London 2009, see wikipedia

Pattern 3 - throw exception

Our other choice is to throw an exception.

import DB from 'my-synchronous-database';
function getUser(id : UserID) : User {
const user = DB.getUserById(id);
if (user) {
return user;
} else {
throw new Error(`Cannot find the user by id ${id}`);
}
}

Now we have an error message but now we introduced another side effect: the exception. If you don't catch the exception, in most cases, your program will crash.

In JavaScript there is no way I can tell by using a function if it will throw or not. Java helps because the tooling will warn you that you are using a throwable function. Still no one likes seeing a nullExceptionPointer in Java land. Not fun.

Pattern 4 - return a result type

What if we wanted to both return an error message if something goes wrong and also not introduce side effects.

This is the Result type. This is also called the Maybe type.

This thing is baked into the standard library of newer programming languages like Rust and Elm. We have std::result in Rust and the Result Type in Elm. Some newer languages don't implement exceptions and treat errors as data like Go, Rust, and Elm.

Since this article is using TypeScript, I'm going to use the library neverthrow but there are others to choose from. This will also work in plain JavaScript too.

Let's look at neverthrow's Result type.

From the neverthrow docs:

type Result<T, E> = Ok<T, E> | Err<T, E>

Ok<T, E>: contains the success value of type T

Err<T, E>: contains the failure value of type E

And here it is in action.

import { Result, ok, err } from 'neverthrow';
import DB from 'my-synchronous-database';
type DBError = string; // type alias for error message

function getUser(id : UserID) : Result<User, DBError> {
const user = DB.getUserById(id);
if (user) {
return ok(user); // return instance of OK
 } else {
return err(`Cannot find the user by id ${id}`); // return instance of Err
 }
}

This is an improvement because there are now no side effects and we can return an error message if something goes wrong. I know that when I use this function I will always get a Result.

const userID = 1;
const userResult : Result<User, DBError> = getUser(userID);
if (userResult.isOK()) {
console.log(userResult.value);
} else {
console.log(userResult.error);
}

If you try to retrieve userResult.value before you have checked isOK() the TS compiler won't let you. Pretty awesome.

JavaScript tooling

tslint-immutable is a plugin for TSlint that has several options to prevent throwing exceptions. See this set of functional programming rules for TSlint here. Enable no-throw and no-try.

And here is a similar set of rules for eslint.

Other libraries and languages

These ideas are also being explored in other languages. Here are some libraries I found.

C++ std::optional, optional<T>, is a safer way than just returning null. The optional can be empty or it can hold a value of type T. It does not hold an error message. This type is also called Maybe in elm and elsewhere.

C++ Result is a header only library that implements Rust's Result<T, E> type. This type can hold the value or an error.

Python result another Rust inspired result type.

If you want to explore more typed functional programming in TypeScript, check out purify, true myth, or the full featured fp-ts.

Elm Calculator Part 11 - Netlify Deployment

Fri, 22 May 2020 00:00:00 +0000

This post is part of a series. If you wish to support my work you can purchase the PDF book on gumroad.

This project uses Elm version 0.19

Part 1 - Introduction
Part 2 - Project Setup
Part 3 - Add CSS
Part 4 - Basic Operations
Part 5 - Adding Decimal Support
Part 6 - Supporting Negative Numbers
Part 7 - Add Dirty State
Part 8 - Support Keypad Input
Part 9 - Combination Key Input
Part 10 - Testing
Part 11 - Netlify Deployment (this post)

Netlify makes deploying web apps super easy. You point Netlify to a git repository hosted with GitHub, GitLab, or Bitbucket and netlify will build and deploy your project. We will need to add some things to our project so that Netlify will know how to build and deploy our project.

Add deploy script

The only change we need to add to our project for Netlify is to add a build script. We will add that to the package.json. Anything added to the scripts section in a package.json can be run with npm run <script name>. So in our case we can run npm run build and npm will build our project to a dist folder.

{
"name": "elm-calculator",
...
"scripts": {
"build": "<do build stuff here>"
},
...
}

Here is what we need to do to make a build.

mkdir -p dist # make a dist folder if not already there
elm make src/Main.elm --optimize --output=dist/elm.js # make optimized build and output to dist/elm.js
cp index.html dist # copy index.html to build directory
cp style.css dist # copy style.css to build directory

And then we add it to our package.json so we can run it with npm run build.

{
"name": "elm-calculator",
...
"scripts": {
"build": "mkdir -p dist && elm make src/Main.elm --optimize --output=dist/elm.js && cp index.html dist && cp style.css dist"
},
...
}

Configure Netlify

Now we need to point Netlify to our git repository.

First you need to register for an account on Netlify. After you can log in to your netlify account you need to go to the dashboard at https//app.netlify.com.

After you click on "New site from Git" you will need to choose you git hosting service. I am hosting this project on GitLab so I will choose that one.

Netlify will ask you to allow permission to access you repositories on the chosen git provider. After you login and give permission you will choose a repository.

Next is the most important step. We tell Netlify what command to run to build our project and with directory to deploy from. The build command needs to be set to npm run build and the publish directory needs to be set to dist. See

Click on "deploy site". If all goes well you should see that your build is in queue waiting to be built.

When it is ready you can click on the link provided and see you app live on the internet to share with the world.

If you want a custom Netlify sub-domain name click on "Site settings". Then click on "Change site name". You can then change the name to something like "elm-calculator". Your project would then be made available at https://elm-calculator.netlify.com.

We're done

Congratulations for making it to the end of this project. I learned a lot putting this together and I hope you learned a lot as well.

Together we build an Elm application from the ground up and deployed it to netlify for all the world to see.

Elm Calculator Part 10 - Testing

Fri, 15 May 2020 00:00:00 +0000

This post is part of a series. If you wish to support my work you can purchase the PDF book on gumroad.

This project uses Elm version 0.19

Note: ellie-app does not support splitting out your code into modules and files. So there is no ellie link for this chapter.

We will be using a newer Elm package called elm-program-test. It allows us to test our application as a whole. It will stand up the application and allow us to test it as if a user were clicking through the application.

Some Refactoring

In order to test our program we need to expose some of our functions in Main.elm.

module Main exposing (Model, Msg, init, main, update, view)

We also need to make our elm program use Browser.document instead of Browser.element since we will be using ProgramTest.createDocument.

Elm has different ways to create a program. Browser.element is good for creating a small elm application that you embed into the page on a specific DOM node. What if you want Elm to take over the whole page? That is what Browser.document is for. See the elm-guide for more information about Browser.element and Browser.document.

Note: Since creating this book, I have since learned that you can use ProgramTest.createElement instead and we wouldn't need to do this refactor.

Refactoring is lovely in Elm. Our first step is to start at the highest level of our refactor and let the compiler tell us what to change. So start by changing the main function to return a Browser.document instead of a Browser.element.

The only thing we need to change for this refactor is the view function to return a Browser.Document instead of Html.

The difference with Browser.Document is that the view function now needs a record with a title and a body field. We can place our previous view html stuffs inside the body field.

view : Model -> Browser.Document Msg
view model =
{ title = "Elm Calculator"
, body =
[ div []
[ h1 [ class "h1" ] [ text "RPN Calculator" ]
, ...

Write the test

First we need to install everything we need. We need the elm-test command line program because we need something to launch and execute our tests. This is our test runner if you have used something like pytest.

npm install --save-dev elm-test

We also need to install the corresponding elm packages as well.

elm install elm-explorations/test
elm install avh4/elm-program-test

To get a simple example test run elm-test init in your project folder.

npx elm-test init

Now run the test you just created.

npx elm-test

You should get a test report.

Create a new file in the tests directory called CalculatorTest.elm.

The test is short (less than 40 lines of code). I'll walk through the most interesting part.

all : Test
all =
describe "basic arithmetic"
[ test "20 × 3 = 60" <|
\() ->
start
|> clickCalcBtn "2"
|> clickCalcBtn "0"
|> clickCalcBtn "←"
|> clickCalcBtn "3"
|> clickCalcBtn "×"
|> expectViewHas
[ text "60"
]
]

This simulates a user clicking on the number and operator buttons. It then checks that the number 60 is somewhere on the page. Try playing with this and adding another test.

The next and last chapter will cover deploying our Elm application to netlify. If you got this far, congratulations! We're almost finished. I get a lot of satisfaction with web projects because they are so easy to share with the world. I'll show you how in the next chapter.

Ryan Frazier's Blog

Some COVID Numbers

Microbit Asteroids

TLDR;

Light up an LED

The LED grid

Button Input

Making our rocket

Problem 1

Problem 2

Asteroids

Game Over

Bonus

Add sound

Keep Score

Multiple Asteroids

What Is Functional Programming

FP Vocabulary

Pure Functions

What is a side effect?

Referential Transparency

No For Loops?

Currying

Exception Throwing is a Side Effect

JavaScript helper libraries

JS Libraries

TypeScript Libraries

Other Resources

My Side Projects

Table of Contents

KnowYourTheory

Frazier Piano Studio

Music Scale Explorer

Circle of Fifths Explorer

Elm Piano Teacher

Lilypond in Markdown

Popcorn Cove Subscriptions

Lemmings Clone

Dr Doug's Pediatrics

Introduction to Algebraic Data Types

Why are they useful?

Animal Names

Immutability

An example with error handling

My First 5 Day Fast

My experience with fasting

The purpose of the extended fast

Preparation

Day 1 - Sunday July 5, 2020

Day 2 - Monday July 6, 2020

Day 3 - Tuesday July 7, 2020

Day 4 - Wednesday July 8, 2020

Day 5 - Thursday July 9, 2020

Breaking the fast

First meal

Second meal

The day after breaking the fast

Case Statement in Typescript

Exceptions Considered Harmful

Pattern 1 - return true or false

Pattern 2 - return null if failed

Pattern 3 - throw exception

Pattern 4 - return a result type

JavaScript tooling

Other libraries and languages

Elm Calculator Part 11 - Netlify Deployment

Add deploy script

Configure Netlify

We're done

Elm Calculator Part 10 - Testing

Some Refactoring

Write the test