EISA IN 10 MINUTES
Belleve Invis

ASYNCS
 Means ubobstructive
 Getting important
– Ajax
– Resource management
– Node.js I/O
 Hard to write in pure JavaScript

THREE SEQUENTIAL TASKS IN JAVASCRIPT
taskA(function(){
taskB(function(){
taskC(function(){
finish()
})
})
})

KEY PROBLEMS
 Nested functions!
– My screen is narrow
 Hard with loops
 Hard with abstraction
 Code locality is broken

EXAMPLE: TASKS DEFINED IN A LIST, ACT IN ORDER
var tasks = […];
var actTasks = function(tasks, deploy){
var current = 0;
var act = function(){
tasks[current]();
current ++;
if(tasks[current]) deploy(act)
}
deploy(act)
}
actTasks(tasks, function(f){ setTimeout(f, 1) });

THAT IN EISA
var flow = async {
for var task in tasks:
wait! 0;
task()
end
}
flow()

EISA IS
 A new language
– So, no capacity requirements
 JavaScript targeted
 Designed for interactive developments
– So, asyncs

ORIGIN: GAME MAKING
 Defining game data – Optimized syntax for DSL
 Game flow – Asyncs
 Large scale RPGs – Module system
 Now is general-use

DEMONSTRATION: 3D SCENE
 http://typeof.net/lab/d2
 Do not focus on the renderer

DEMO IN ACTION
var loadImage(src, callback):
……
img.onload = function(){ callback img }
img.src = src
end
var loadTextures = async {|callback|
var texture = getTextureData loadImage! 'images/texture.png'
……
if callback:
callback { texture: texture, heightMap: heightMap }
end
};

MASTER FLOW
var flow = async {
……
setTextures loadTextures!()
……
gameClock.perk()
while true:
renderFrame();
……
gameClock.wait!()
end
console.log 'Demo Finished'
}

HOW ABOUT USING TRADITIONAL WAY?
var flow = function(){
loadTextures(textureLoaded)
}
var textureLoaded = function(textures){
……
gameClock.perk()
gameLoop()
}
var gameLoop = function(){
renderFrame();
gameClock.wait(gameLoop)
}

TREND
 ECMAScript Harmony
– Syntax extensions
– Semantic fixes
 JavaScript-targeted languages
– From existing languages, e.g. GWT
– New-created languages, e.g. CoffeeScript
 JavaScript modulation
– Necessaria – module system in Eisa

FOCUS EISA
 http://github.com/infinte/eisa
 Fork Me!

Q&A
 Belleve Invis
– Born in 1992
– Now in USTC
– be5invis@typeof.net
– http://typeof.net
 Eisa
– Since 2010
– http://github/infinte/eisa

Thank you
AGO VOBIS GRATIAS