EISA is a new programming language targeted towards JavaScript that is designed for asynchronous and interactive development. It addresses key problems with asynchronous programming in JavaScript like nested callbacks and broken code locality. In EISA, asynchronous tasks can be defined sequentially using async/await rather than nested callbacks. This was demonstrated with a 3D scene loading example where the entire workflow was defined asynchronously without nested functions. EISA originated from game development needs but can now be used for general purposes. It focuses on providing an optimized syntax for domain-specific languages while remaining compatible with JavaScript.

1. EISA IN 10 MINUTES
Belleve Invis

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

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

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

5. 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) });

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

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

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

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

10. 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
};

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

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

13. 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

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

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

16. Thank you
AGO VOBIS GRATIAS