Coffee Script Premiere

CoffeescriptPremiere

Introduction to Coffeescript

Samstag, 16. Oktober 2010

What is Coffescript?

• Preprocessor for Javascript

• Alternative Syntax

• Embraces expressiveness


What is Coffescript?

• Coffeescript is a compiler

• A small DSL on Jison

• Available as Node.js Utility


Prequerities

• npm install coffee-script

• brew install coffee-script

• coffee --version


The Ingredients


Significant Whitespace

• Blocks = Indentation

• last evaluated object will be returned



var cube, square;square = function(x) { return x * x;};cube = function(x) { return square(x) * x;};



square = (x) -> x * x

cube = (x) -> square(x) * x


Assignment

number = 42opposite = true


Conditions

number = -42 if oppositenumber = 1337 unless noHacker

if happy and knowsIt clapsHands() chaChaCha()else showIt()


Switchswitch day when "Mon" then go work when "Tue" then go relax when "Thu" then go iceFishing when "Fri", "Sat" if day is bingoDay go bingo go dancing when "Sun" then go church else go work


Functions

square = (x) -> x * x


Arrays

list = [1, 2, 3, 4, 5]matrix = [ 1, 0, 1 0, 0, 1 1, 1, 0]


Objects

singers = { Jagger: "Rock", Elvis: "Roll" }math = root: Math.sqrt square: square cube: (x) -> x * square x


Array comprehension

for roid in asteroids for roid2 in asteroids when roid isnt roid2 roid.explode() if roid.overlaps roid


_ref = asteroids;for (_i = 0, _len = _ref.length; _i < _len; _i++) { roid = _ref[_i]; _ref2 = asteroids; for (_j = 0, _len2 = _ref2.length; _j < _len2; _j++) { roid2 = _ref2[_j]; if (roid !== roid2) { if (roid.overlaps(roid2)) { roid.explode(); } } }}


Loops

if this.studyingEconomics buy() while supply > demand sell() until supply > demand


deliverEggs = function() { var _ref, _result2, dozen, i; _result2 = []; _ref = eggs.length; for (i = 0; (0 <= _ref ? i < _ref : i > _ref); i += 12) { _result2.push((function() { dozen = eggs.slice(i, i + 12); return deliver(new eggCarton(dozen)); })()); } return _result2;};


Try Catch

try allHellBreaksLoose() catsAndDogsLivingTogether()catch error print errorfinally cleanUp()


The Spice


Classclass Animal constructor: (@name) ->

move: (meters) -> alert @name + " moved " + meters + "m."

class Snake extends Animal move: -> alert "Slithering..." super 5

class Horse extends Animal move: -> alert "Galloping..." super 45

sam = new Snake "Sammy the Python"tom = new Horse "Tommy the Palomino"

sam.move()tom.move()


Open Classes

String::dasherize = -> @replace /_/g, "-"


Static Variables

String::dasherize = -> @replace /_/g, "-"


Fat Arrow

Account = (customer, cart) -> @customer = customer @cart = cart

$('.shopping_cart').bind 'click', (event) => @customer.purchase @cart


The Sugar


author = "Wittgenstein"quote = "A picture is a fact. -- #{author}"

String Interpolation


RegExp Interpolation

sep = "[.\\/\\- ]"dates = /\d+#{sep}\d+#{sep}\d+/g


Splats

race = (winner, runners...) -> print winner, runners


Existence

alert "I knew it!" if elvis?speed ?= 140lottery.drawWinner()?.address?.zipcode


Aliases

is compiles to ===isnt compiles to !==not compiles to !and compiles to &&or compiles to ||on, yes compile to trueoff, no compile to false


The Toolchain


Editor

• TextMate bundlehttp://github.com/jashkenas/coffee-script-tmbundle

• VIMhttp://github.com/kchmck/vim-coffee-script


http://github.com/jashkenas/coffee-script-tmbundle




http://github.com/kchmck/vim-coffee-script


Cakesys = require 'sys'fs = require 'fs'exec = require('child_process').execspawn = require('child_process').spawn

task 'watch', 'watches and compiles coffee', -> puts "Spawning coffee watcher" coffee = spawn 'coffee', ['-cwl', '-o', 'javascripts', 'coffeescripts']

[coffee].forEach (child) -> child.stdout.on 'data', (data) -> sys.print data exec "growlnotify -m \"#{data}\" -t \"Cakefile\"" child.stderr.on 'data', (data) -> sys.print data exec "growlnotify -m \"#{data}\" -t \"Cakefile\""


Rails3 Integration

• Barristahttp://github.com/Sutto/barista

• Bistro Carhttp://github.com/jnicklas/bistro_car






Resources

• IRC Channel#coffeescript on Freenode

• Official Websitehttp://jashkenas.github.com/coffee-script/


http://jashkenas.github.com/coffee-script/

http://jashkenas.github.com/coffee-script/

Thank you

• Sebastian Deutsch

• 9elements.com

• @sippndipp on Twitter


Coffee Script Premiere

Documents

Transcript of Coffee Script Premiere