OliverJAsh

Option vs non-Option

	Option<T>	non-Option (T | undefined)
accessing property	userOption.map(user => user.age)	userNullish?.age
calling a method	userOption.map(user => user.fn())	userNullish?.fn()
providing fallback	ageOption.getOrElse(0)	ageNullish ?? 0
filter	ageOption.filter(checkIsOddNumber)	`ageNull

shazron

#!/bin/bash

# Description:
#     Delete all `greenkeeper/*` branches of your remote.
# Instructions:
#     Run the script with the `--help` flag.

ORIGIN=origin
DRY_RUN=0
THIS=`basename "$0"`

OliverJAsh

JavaScript function declarations vs. expressions

Declarations

Pros

• Sync/async generator forms

Cons

• Not constant, can be reassigned
• Hoisting can result in runtime exceptions (https://twitter.com/OliverJAsh/status/1247240674388447234)

caseywatts

Short link to this page: http://caseywatts.com/ptt

Other gists & tricks: http://caseywatts.com/gists-and-tricks

Unrelated update: my book is out! Debugging Your Brain is an applied psychology / self-help book

Push To Talk in a Google Hangout (Meet)

1. Save this bookmarklet. Right-click on boomarks toolbar Add Page...

• Name: PTT (push to talk) or whatever you'd like (maybe short so it stays on your bookmarks toolbar)

slikts

const Range = (a, b) => Array.from({ length: b - a }, (_, i) => a + i)
const NumTest = (n, text) => k => !(k % n) ? text : ''
const Tests = data => Object.entries(data).map(([n, text]) => NumTest(n, text))
const RangeTest = tests => n => tests.map(fn => fn(n)).join('') || n
const RangeMap = (a, b, tests) => Range(a, b).map(RangeTest(tests))
const fizzBuzz = (a, b) => RangeMap(a, b, Tests({
  5: 'Fizz',
  3: 'Buzz',
}))

zkxs

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,02,00,00,00,64,00,3a,00,00,00,00,00

ljharb

Array Iteration

https://gist.github.com/ljharb/58faf1cfcb4e6808f74aae4ef7944cff

While attempting to explain JavaScript's reduce method on arrays, conceptually, I came up with the following - hopefully it's helpful; happy to tweak it if anyone has suggestions.

Intro

JavaScript Arrays have lots of built in methods on their prototype. Some of them mutate - ie, they change the underlying array in-place. Luckily, most of them do not - they instead return an entirely distinct array. Since arrays are conceptually a contiguous list of items, it helps code clarity and maintainability a lot to be able to operate on them in a "functional" way. (I'll also insist on referring to an array as a "list" - although in some languages, List is a native data type, in JS and this post, I'm referring to the concept. Everywhere I use the word "list" you can assume I'm talking about a JS Array) This means, to perform a single operation on the list as a whole ("atomically"), and to return a new list - thus making it mu

voltrevo

Comparison of Typescript and Flow

Common Features

• Lots of type inference

• Null/undefined checking

Similar syntax

broofa

#!/bin/bash
cd "$(git rev-parse --show-toplevel)"
ESLINT="node_modules/.bin/eslint"
pwd

if [[ ! -x "$ESLINT" ]]; then
  printf "\t\033[41mPlease install ESlint\033[0m (npm install eslint)\n"
  exit 1
fi

rla

var flatten = (a, r, cb) => {
    if (typeof a.length === 'undefined') {
        r.push(a);
        return cb;
    } else if (a.length === 0) {
        return cb;
    } else {
        return flatten(a[0], r, () => flatten(a.slice(1), r, cb));
    }
};