A 5 minute lightning talk on the Fantom programming language. Presented to the London Software Craftsmanship Community (LSCC) Talks Event #14 in London on Thursday 16 July 2015. Transcript follows: What is Fantom? Fantom is an elegant Open Source programming language. Before I say more, lets first look at some other languages... Slide 2 Java gets compiled into .class files, which get run on the JVM. .NET languages like C# are compiled into assemblies, which get run on the CLR. In a similar vein, Fantom (.fan) get compiled into .fcode files that are used by the Fantom Runtime. which in turn can run on... both the JVM AND the CLR! Slide 3 But better than that, Fantom also compiles to javascript, which runs on any browser. The core language tackles all the hard stuff so you don't have to, and gets it right! Slide 4 It has immutable classes, their values can not change, they are set in time, preserved for ever, like mosquitoes in amber! Concurrency in Fantom uses the Actor paradigm, just like the Akka framework in java. Each thread runs inside it's own Actor and the only way to communicate with an Actor is to pass it messages. There is no mutable state, no volatile syncing and no borked double locking mechanisms, just message passing. In Fantom the only messages you can pass to an Actor are... immutable classes! Why? Because they're lightweight and thread safe! Slide 5 All Fantom objects can be serialised to a human readable string! And not some cryptic binary code. And Fantom objects when serialised look like Fantom source code! No more dodgy XML parsing for me! Slide 6 Fantom has it's own Windowing Toolkit, which wraps the eclipse SWT, which runs on any machine with Java installed. But the cool thing is, that the same windowing desktop code also runs on any browser... Slide 7 The Fantom language is statically typed, but has unique and lenient type inference which shrinks (equivalent) Java and C# code. It also has a concise and functional API which shrinks the code even further. Less code, less cognitive overhead… Oh yes, the core API. It's written from scratch, and it's fast. Very fast. Some even say -> faster than Java! As well as the big things, Fantom also pays attention to the small details that affect us programmers every day. Slide 8 Small things such as Nullable types. Variables cannot be null unless you explicitly allow it. So Sir Charles Antony Richard Hoare, inventor of the billion dollar mistake, "In your face!" Slide 9 Fantom also has Elvis. Slide 10 So, what can Fantom be used for? Well I personally have built: Desktop applications Slide 11 Games - most notably Gundam, a shoot'em'up that can also run in a browser. Slide 12 And, given they are so prolific nowadays, a multitude of Web applications. Slide 13 And Why? Because Fantom IS fun and it Gets Stuff Done!

1. Fantom is Fun
& Gets Stuff Done
SlimerDude
aka
Steve Eynon

2. JVM
CLR
Fantom
Runtime

3. Javascript

4. const class Dna {
const Str sequence
const Int age
….
}
Thread
(Actor)

5. @Serializable
class Dna {
Str sequence := "CAGAGTA..."
Int age := 42
Bool dinosaur := true
Void mutate() {
// ...
}
}
class Dna {
Str sequence = "CAGAGTA..."
Int age = 42
Bool dinosaur = true
}
Fantom Source Code Fantom Serialised

6. Desktop
Browser
Same gfx code runs on…

7. Fantom Source Code
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Java Fantom

8. Tony Hoare
nullInventor of

9. Elvis
text := nullable ?: "null"
No!
Yes!

11. Games

13. Fantom is Fun
& Gets Stuff Done
SlimerDude
aka
Steve Eynon

14. Fantom is Fun
& Gets Stuff Done
SlimerDude
aka
Steve Eynon

15. Fantom is Fun
& Gets Stuff Done
SlimerDude
aka
Steve Eynon