Darvesh darvesh

tmux shortcuts & cheatsheet

start new:

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start new with session name:

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Category theory jargon cheat sheet

A primer/refresher on the category theory concepts that most commonly crop up in conversations about Scala or FP. (Because it's embarassing when I forget this stuff!)

I'll be assuming Scalaz imports in code samples, and some of the code may be pseudo-Scala.

Functor

A functor is something that supports map.

ES6 JavaScript Compose Function

Definition

const compose = (...fns) =>
  fns.reduceRight((prevFn, nextFn) =>
    (...args) => nextFn(prevFn(...args)),
    value => value
 );

'Include' in Sequelize: The One Confusing Query That You Should Memorize

When querying your database in Sequelize, you'll often want data associated with a particular model which isn't in the model's table directly. This data is usually typically associated through join tables (e.g. a 'hasMany' or 'belongsToMany' association), or a foreign key (e.g. a 'hasOne' or 'belongsTo' association).

When you query, you'll receive just the rows you've looked for. With eager loading, you'll also get any associated data. For some reason, I can never remember the proper way to do eager loading when writing my Sequelize queries. I've seen others struggle with the same thing.

Eager loading is confusing because the 'include' that is uses has unfamiliar fields is set in an array rather than just an object.

So let's go through the one query that's worth memorizing to handle your eager loading.

The Basic Query

Copied from http://code.lancepollard.com/complete-list-of-html-meta-tags/

Basic HTML Meta Tags

<meta charset='UTF-8'>
<meta name='keywords' content='your, tags'>
<meta name='description' content='150 words'>
<meta name='subject' content='your website's subject'>
<meta name='copyright' content='company name'>

	/*
	* parse_link_header()
	*
	* Parse the Github Link HTTP header used for pageination
	* http://developer.github.com/v3/#pagination
	*/
	function parse_link_header(header) {
	if (header.length == 0) {
	throw new Error("input must not be of zero length");
	}

	yum install rpm-build cabextract ttmkfdir
	wget http://corefonts.sourceforge.net/msttcorefonts-2.5-1.spec
	rpmbuild -bb msttcorefonts-2.5-1.spec
	rpm -ivh $HOME/rpmbuild/RPMS/noarch/msttcorefonts-2.5-1.noarch.rpm
	fc-cache -f -v

	// [B](f: (A) ⇒ [B]): [B] ; Although the types in the arrays aren't strict (:
	Array.prototype.flatMap = function(lambda) {
	return Array.prototype.concat.apply([], this.map(lambda));
	};

	#!/bin/bash

	for file in $(git diff --cached --name-only \| grep -E '\.(js\|jsx)$')
	do
	git show ":$file" \| node_modules/.bin/eslint --stdin --stdin-filename "$file" # we only want to lint the staged changes, not any un-staged changes
	if [ $? -ne 0 ]; then
	echo "ESLint failed on staged file '$file'. Please check your code and try again. You can run ESLint manually via npm run eslint."
	exit 1 # exit with failure status
	fi
	done

	axios({
	url: 'http://localhost:5000/static/example.pdf',
	method: 'GET',
	responseType: 'blob', // important
	}).then((response) => {
	const url = window.URL.createObjectURL(new Blob([response.data]));
	const link = document.createElement('a');
	link.href = url;
	link.setAttribute('download', 'file.pdf');
	document.body.appendChild(link);