Why Scala for Web 2.0?

Flash Player 9 (or above) is needed to view presentations.
We have detected that you do not have it on your computer. To install it, go here.

more share options
Embed For WordPress.com

Without related presentations

Came to previous C4s for Io, Erlang. Have programmed for money in Java, JavaScript, C, PHP, Perl, Ruby, and Python. Have programmed for fun, love, or spite in x86 Assembly, Erlang, Lua, Objective-C, various Lisps, Haskell, O-Caml, C++, Io, Erlang.

Ruby’s poor VM performance, monkeypatching and cultural issues, questionable for large systems. We had new services to build, didn’t want to continue with Ruby.

My personal criteria for a good systems language.

Why not these languages? Talk about their issues. We ultimately knew we wanted a JVM language, just not Java.

Ruby’s poor VM performance, monkeypatching and cultural issues, questionable for large systems. We had new services to build, didn’t want to continue with Ruby.

The JVM has chops. Address Java interoperability, Martin Odersky’s credentials, etc. Worse comes to worse, just fall back to Java. Most other JVM-hosted languages can’t claim the same speed as Scala.

The “concurrency crisis” has been underway since the early 1990s. Ref: HOPL2 intro speech.
Scala handles actors as nicely as Erlang and Io. Actors are neat, but we haven’t made extensive use of them at Twitter just yet. Also Pi and Join Calculi.

A pragmatic approach to data structure mutability. Most data structures available in mutable and immutable flavors. Requires thoughtful decision-making, but that pays off.

Static typing is a blessing and a curse. Scala lets you ignore typing until you can put it to work for you.

Once you have this feature in a language, you simply can’t do without it. Passing functions around is awesome - a bit like function pointers. Also: “higher-order” methods (methods that take other methods, like ‘map’), anonymous methods. Everything is an expression, everything has a value.

Once you’ve gotten used to Ruby’s modules, it’s another difficult language feature to give up. Subclassing can be a nightmare, and isn’t always the correct design solution. Traits enable powerful abstraction of cross-cutting concerns.

Every programmer matches patterns all day, every day. It’s just that most languages don’t have a lexical facility for making that task easier.

XML ain’t going away any time soon. If you have to interact with XML a lot, Scala is an awesome choice. It’s got that JavaScript+JSON peanut butter n’ jelly quality.

Address those features particular to Scala: case classes, properties, existential types, implicits.

The bad, the ugly.

Ruby’s poor VM performance, monkeypatching and cultural issues, questionable for large systems. We had new services to build, didn’t want to continue with Ruby.

37 Favorites

Stone Gao, Software Engineer at Ekohe, favorited this 5 days ago
Tags scala
Arto Bendiken at Freelance, favorited this 3 weeks ago
Tags scala twitter
Hasan Tayyar BESIK, IT Manager, Web Developer at Alle, favorited this 2 months ago
Gentle Yang, Software Developer at BGI, favorited this 2 months ago
Tags web20 scala
joa.zhang favorited this 2 months ago
Tags scala
Hiroshi Ono at SGI Japan, Ltd., favorited this 2 months ago
mrphoebs favorited this 5 months ago
Pavlo Kapishin, CTO at Original Coding, favorited this 6 months ago
Tags scala
narbs favorited this 6 months ago
kkganesan favorited this 6 months ago
Tags scala web2 twitter
Stefane Fermigier, Founder and Chairman at Nuxeo, favorited this 6 months ago
Tags scala
bisceglie favorited this 6 months ago
xiaofengw favorited this 6 months ago
Tags web20
adorepump, software developer favorited this 6 months ago
Tags scalajava
duraionly, programmer favorited this 6 months ago
Tags java scala

Why Scala for Web 2.0? - Presentation Transcript

Why Scala for Web 2.0?
Hi. I’m Alex Payne, API Lead at Twitter, Inc. Also, co-author of Programming Scala, out later this year from O’Reilly.
A brief history of the languages behind Web 2.0.
Let’s talk about recession engineering.
Can we still afford to build things we love with tools we love?
fast functional expressive statically typed object-oriented concurrent beautiful
C C++ Ruby PHP Python Erlang Java [JVM dynamic languages]
And then, there’s Scala.
Features.
Java compatibility keeps your ROI returning.
Actors keep concurrency simple.
Immutability keeps concurrency predictable.
Type inference keeps code clean.
First-class functions keep things exible.
Traits keep behavior reusable.
Pattern matching keeps your needles out of haystacks.
XML literals and query methods keep XML tolerable.
More: case classes properties existential types implicit conversions lazy evaluation parser combinators monads annotations ... !
The price: complexity. But it’s worth it.
Wins.
A queuing system that takes the hits.
An API test suite that helps us sleep.
People search that returns in milliseconds.
Community.
Groups: Bay Area Scala Enthusiasts (BASE) Chicago Area Scala Enthusiasts (CASE) New York Scala Enthusiasts (NYSE) etc. etc.
Education: Programming Scala Programming in Scala The Busy Java Developer’s Guide... Why Scala? Introduction to High-Level Prog’ing... Scala Language Speci cation
Blogs &c.: Code Commit Coderspiel Scala-Blogs Graceless Failures Delicious Reddit FriendFeed Twitter Search
Tools: IDEs: Eclipse, NetBeans, IDEA Editors: Emacs, VIM, TextMate JavaRebel Whatever JVM tools you like!
Libraries and frameworks Lift Specs ScalaCheck Con ggy Scalax, Scalaz every Java library ever even libraries in other JVM languages!
So, why Scala for Web 2.0?
Thank you. Questions? scala-lang.org bit.ly/progscala twitter.com/al3x al3x.net