Colin Eberhardt ColinEberhardt

A Guide to Functional Programming Lingo for JavaScripters

Functional programming gets a bad wrap about being too hard for mere mortals to comprehend. This is nonsense. The concepts are actually quite simple to grasp.

The jargon is the hardest part. A lot of that vocabulary comes from a specialized field of mathematical study called category theory (with a liberal sprinkling of type theory and abstract algebra). This sounds a lot scarier than it is. You can do this!

All examples using ES6 syntax. wrap (foo) => bar means:

function wrap (foo) {

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

Generate the list yourself:

$ cd /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS*.sdk/System/Library/Frameworks/UIKit.framework/Headers
$ grep UI_APPEARANCE_SELECTOR ./*     | \
  sed 's/NS_AVAILABLE_IOS(.*)//g'     | \
  sed 's/NS_DEPRECATED_IOS(.*)//g'    | \
  sed 's/API_AVAILABLE(.*)//g'        | \
  sed 's/API_UNAVAILABLE(.*)//g'      | \
 sed 's/UI_APPEARANCE_SELECTOR//g' | \

Collections

each(array)

Underscore example:

_.each([1, 2, 3], function(num) { alert(num); });

	//load Global Terrorism Database
	//Copy/Paste the load script below into your Neo4j-shell command-line utility

	//In order to accelerate the loading process, you want to download the CSV file from
	//https://www.dropbox.com/s/oequ58lrp8f9w6v/gtdb_transform.csv?dl=1 and then to a local file.
	//After that, you would of course need to replace the URL in all of the queries below, and replace it with
	//load csv with headers from "file:/path/to/your/file.csv" as csv

	//load the countries
	load csv with headers from "https://www.dropbox.com/s/oequ58lrp8f9w6v/gtdb_transform.csv?dl=1

	// Playground - noun: a place where people can play

	import Foundation

	typealias Byte = UInt8

	protocol GenericIntegerType: IntegerType {
	init(_ v: Int)
	init(_ v: UInt)
	init(_ v: Int8)

	func s(x:Int)->[Int]{
	return x<2 ?
	[]:
	// Single line closure has implicit return
	// Closure type is Int->[Int]
	{[$0]+s(x/$0)}( // Argment to closure
	// Filter full range 2 to x and take first factor (non lazy)
	// x%x is guaranteed to be 0 so safe to take first element
	filter(2...x){x % $0 == 0}[0]
	)


	struct InputStreamGenerator : Generator {
	var inputStream : NSInputStream
	var chunkSize : Int

	init(inputStream : NSInputStream, chunkSize : Int) {
	self.inputStream = inputStream
	self.chunkSize = chunkSize
	}

	var dom = Bloop.dom;

	var Box = Bloop.createClass({
	getInitialState: function() {
	return { number: 0 };
	},

	updateNumber: function() {
	this.state.number++;
	},

	@synthesize firstName = _firstName;
	@synthesize txtFirstName = _txtFirstName;

	[RACAbleSelf(self.firstName) subscribeNext:^(id x) { [self firstNameChanged:x]; }];
	[self rac_bind:RAC_KEYPATH_SELF(self.firstName) to:self.txtFirstName.rac_textSubscribable];

	- (void) firstNameChanged:(id)firstName {
	NSLog(@"changed: %@", firstName);
	}