blrobin2’s gists

blrobin2 / autosave_associated_many_to_many.rb

Created January 6, 2021 15:16

A Rails model mix-in for handling many-to-many updates and nested attributes

	module AutosaveAssociatedManyToMany
	extend ActiveSupport::Concern

	# When using a combination of autosave and accepts nested_attributes_for for a many-to-many association
	# By default, Rails always creates new records
	# If you have unique indexes on the association keys on your bridge table, you'll just get errors
	# By defining a matcher, you provide a way to determine whether a "new" record is actually an existing record
	# By defining an updater, you provide a way to update values on a many-to-many (changing an association to a new field
	# or updating any additional fields on the bridge table)
	#

blrobin2 / complex_sorting.rb

Created August 11, 2020 14:33

How to do combination ASC, DESC sorting in Ruby

blrobin2 / end_of_time.js

Created May 30, 2020 13:15

A way of representing the concept of a MAX_DATE or END_OF_TIME constant

	const END_OF_TIME = new Date(parseInt('9'.repeat(15), 10))
	// Thu Sep 26 33658 21:46:39 GMT-0400 (Eastern Daylight Time)

	// Example usage: default for date comparisons where you want to ensure the default is greater than
	// any of the provided dates
	const dateFromMMDDYYYY = mmddyyyy => new Date(Date.parse(mmddyyyy))

	const dates = ['02/29/1984', '03/01/2055', '02/29/2244']
	const earliest_date = dates.map(dateFromMMDDYYYY)
	.reduce(

blrobin2 / pythagorean-triples.ts

Created April 9, 2019 18:50

Pythagorean Triples with MATH

	/**
	* Function: pythagorean Triples
	*
	* How to derive the side_b formula:
	* - a² + b² = c²
	* - b² = c² - a²
	* - 2bc + b² + b² = c² - a² + 2bc + b²
	* - 2bc + b² + b² = c² + 2bc + b² - a² // Line above reorganized to see simplification
	* - 2bc + b² + b² = (b + c)² - a²
	* - 2b² + 2bc = (b + c)² - a²

blrobin2 / ord-sort.ts

Created December 7, 2018 13:44

Ord-based Bubble sort with TYPES

	interface Setoid<T> {
	equals(that: T): Boolean;
	}

	interface Ord<T> extends Setoid<T> {
	lte(that: T): Boolean;
	}

	class Coord implements Ord<Coord> {

blrobin2 / ord-sorts.js

Last active June 12, 2022 09:26

Ord-based Bubble, Merge, and Quick Sort

	// A demonstration of sorting objects with Ord instances
	// equals :: Setoid a => a ~> a -> Boolean
	// lte :: Ord a => a ~> a -> Boolean

	/*
	* Data Constructors, and their Setoid and Ord instances
	*/

	// I'm using the daggy library to make constructors https://github.com/fantasyland/daggy
	const daggy = require('daggy')

blrobin2 / composing-monads.hs

Last active August 29, 2018 19:58

Implement join :: M (N (M (N a))) -> M (N a), given distrib :: N (M a) -> M (N a) and assuming M and N are instances of Monad

	import qualified Control.Monad as M (join)

	-- Not necessarily possible function, but if it is, then joining on Monad stack is possible
	distrib :: (Monad m, Monad n) => n (m a) -> m (n a)
	distrib = undefined

	join :: (Monad m, Monad n) => m (n (m (n a))) -> m (n a)
	join mnmna = do
	nmna <- mnmna
	nna <- distrib nmna

blrobin2 / url.js

Created July 9, 2018 18:46

URL string building helpers

	function createUrl(base, paramObj) {
	return [base, createUrlParams(paramObj)].join(base.includes('?') ? '&' : '?')
	}

	function createUrlParams(paraObj) {
	return Object.entries(paramObj).map(([key, val]) => `${key}=${val}`).join('&')
	}

	// Sample usage
	const url = createUrl('http://localhost:3000', { redirect: true })

blrobin2 / a.js

Last active March 30, 2018 12:54

James Moore's Ramda Tutorial (https://www.youtube.com/playlist?list=PLs0HJRuXPAqu6OLH_2K0K6jlxFP7erHDy) My solution

	const R = require("ramda");
	const table = require("text-table");

	const kelvinToCelcius = k => k - 273.15;
	const kelvinToFahrenheit = k => k * 9 / 5 - 459.67;

	const updateTemperature = R.curry((conversionFn, city) => {
	const updatedTemperature = Math.round(conversionFn(city.temp));
	return R.merge(city, { temp: updatedTemperature });
	});

blrobin2 / buildString.ts

Last active January 8, 2018 00:25

My version of build string by @peterpme

	const buildString = (delimeter: string, ...collection: any[]): string =>
	collection.filter(Boolean).join(delimeter);

	console.log(buildString('/', 'api', undefined, 'users', 123)); // 'api/users/123'

Bennie blrobin2