CodeFest'10. Иноземцев И. — Fantom. Cross-VM Language

Transcript

1. WTF is Fantom? CodeFest, Новосибирск, 2010
2. Java sucks
3. Java sucks public static void javaSucks1() { Map<String, List<String>> wtf = new HashMap<String, List<String>>(); }
4. Java sucks public static void javaSucks2() { new Thread(new Runnable() { @Override public void run() { System.out.println("WTF?"); } }).run(); }
5. Java sucks private int value; public int getCount() { return value; } public void setCount(int value) { this.value = value; } public void javaSucks3() { setCount(getCount() + 1); }
6. Java sucks public void javaSucks4() { try { out.write(new byte[] { 1,2,3}); } catch (IOException e) { System.out.println("Oops!"); } finally { try { out.close(); } catch (IOException e) { } } }
7. Java ≠ JVM
8. JVM rocks
9. JVM Rocks • Most popular and powerful VM in the world • > 15 years on VM market • True cross-platform
10. JVM Rocks • Plenty of frameworks • Application servers • Tooling support • Debugging • Profiling • Code coverage
11. JVM Languages • Java • Scala • Clojure • Groovy • Fantom
12. Fantom • Object-oriented • Statically typed • Open source • Was born in late 2005 • Authors – Brian Frank and Andy Frank • Created for start-up SkyFoundry.com
13. Fantom is more than just yet another JVM language
14. Fantom .fan .fcode .js JVM .NET LLVM Parrot
15. Fantom • Significant developer productivity (comparing to Java) • Safer code • Multi-paradigm support • Interaction with platform
16. Productivity • Type inference • Literals • First-class functions • Closures • Mixins • Small tricks
17. Type inference Infer local variables mc := MyClass() s := "this is a string" duration := 1day Infer generic parameters intList := [1,2,4] strToIntMap := ["a":4, "b":5]
18. Literals Lists [1, 3, 5, 7] ["a", ["b", "cd"]] Maps ["str": "Str", 1: 3, "list": [null, 5]] Types(reflection) Str# sys::Str# Str#capitalize URIs `ftp://user001:pass@ftp.com/mydir/myfile.txt` `http://fantom.org` `/Users/ivaninozemtsev/work/fantom` Duration [1ns, 5ms, 12sec, 3hr, 1day] Ranges [1..5, 2..8, 0..<5]
19. Functions and closures Functions are first class objects //simple signatures |->| voidSig := |->| {} |->Int| returnsInt := |->Int| { 42 } Methods are just function wrappers |Int a, Int b ->Int| plus := Int#plus.func |->| mainFunc := #main.func Functions can bind arguments op := |Method m, Int a, Int b| { m.callOn(a, [b]) } mul := opFunc.bind([Int#mult]) //|Int, Int->Int| plus2 := opFunc.bind([Int#plus, 2]) //|Int -> Int| Closures are exprs returning funcs Str prefix := "" print := |Obj o->Str| { prefix + o.toStr }
20. Mixins mixin FirstLast { abstract Str firstName() abstract Str lastName() } mixin Age{ abstract Int age } mixin WithImpl : FirstLast { Str fullName() { "$firstName $lastName" } } mixin MultiInh : WithImpl, Age { override Str toStr() { "$fullName ($age years old)" } } • Replacement of interfaces • Abstract fields and methods • Methods can have implementation
21. Small convenience tricks Implicit upcasts Derived derived := base Safe invoke person?.phones?.first //null if p == null Elvis operator //alias for this == null ? that : this this ?: that No () for methods w/o args cap := "a".capitalize No ‘return’ for single expr Int negate(Int arg) { arg.negate } ‘isnot’ keyword alwaysFalse := "a" isnot Str
22. Safety • Nullable types • Const fields and classes • No shared mutable state
23. Nullable types • Every type isn’t nullable by default • Obvious errors are caught by compiler • Automatic coercion class Nullable { Void main() { Int? nullable := null Int nonNullable := 0 nonNullable = nullable //runtime err nonNullable = null //compile err do3(null) //compile err do3(nullable) //runtime err } Int do1(Int? arg) { null } //compile err Int do2(Int? arg) { arg } //runtime err Int? do3(Int arg) { arg } }
24. Const types • Const classes contain only const fields • Const fields must be set in constructor • Const fields can have only const type or [List, Map, Func].toImmutable • Static fields must be const • List and Maps can be const or mutable class NonConst { const Int constField Int nonConstField Void mutate() { constField = 4 //compile err nonConstField = 4 //ok } } class Const { new make(Int i, Str[] list) { //implicit call of list.toImmutable this.list = list } const Str[] list }
25. Actor framework • Actors are the only way for multithreading • Actor are const classes extending Actor class • Actors interchange with const or serializable messages • Actors can have private mutable data
26. Actor framework using concurrent const class Logger : Actor { new make(ActorPool pool := ActorPool()) : super(pool) {} override Obj? receive(Obj? msg) { echo(msg); return null } } class Actors { Void main() { logger := Logger() logger.send("Hello") future := logger.sendLater(1sec, "Later") logger.send("Now") future2 := logger.sendWhenDone(future, "After later"); future3 := logger.sendWhenDone(future2, "After after") future3.cancel Actor.sleep(2sec) } }
27. Multiparadigm
28. Declarative style Window { title = "FWT Demo" size = Size(800, 600) Label { text = "Hello, codefest!" }, }.open
29. Declarative style a := AddressBook { Person { first = "Ivan" last = "Inozemtsev" phones = [ Phone { num = "+79139494750"; type = PhoneType.cell}, Phone { num = "+73833631033" type = PhoneType.work } ] }, }
30. Dynamic style Void iAmDynamic(Obj duck) { duck->quack duck->swim("away") }
31. Dynamic style class Dict { Str:Obj? map new make(Str:Obj? map) { this.map = map } override Obj? trap(Str name, Obj?[]? args) { if(args.isEmpty) return map[name]//getter return (map[name] = args.first) //setter } } Void main() { dict := Dict(["foo":5, "bar":"str"]) Str a := dict->foo->toStr //"5" Str b := dict->bar //"str" Obj o := dict->o //null dict->o = 42 }
32. Functional style persons.findAll |Person p->Bool| { p.first == "Ivan" }.map |Person p -> Phone[]| { p.phones }.flatten .exclude |Phone ph->Bool| { ph.type == PhoneType.work }.map |Phone ph->Str| { ph.num }.each { echo(it) }
33. Interaction with platform using [java]org.eclipse.dltk.internal.ui.text using [java]org.eclipse.core.runtime using [java]org.eclipse.dltk.core using [java]org.eclipse.ui.progress class ReconcileListener : IScriptReconcilingListener { private AstView view public new make(AstView view) { this.view = view } override Void aboutToBeReconciled() {} override Void reconciled(ISourceModule? module, Bool forced, IProgressMonitor? progressMonitor) { if (module != null) UpdateJob(view, module).schedule } }
34. OK, what else? • Build scripts on Fantom • API Doc generation • Built-in unit-testing framework • Built-in web server • Interactive shell (REPL)
35. Who’s using it?
36. We are!
37. X5 • Collects, analyzes and groups error reports • Highly concurrent application • Pure Fantom solution • Uses CouchDB
38. F4 • World-class IDE for Fantom written on Fantom • Completion • Navigation • Highlighting • Search • Debugging
39. Terminals • Full-featured xterm compatible terminal • Intense integration with Java • Embedded into Eclipse
40. FPF - Fantom presentation framework • Scene graph-based UI Framework • Same look&feel on Desktop and browsers • HTML5 Canvas on Web • OpenGL Canvas on Desktop
41. And not only
42. Kloudo.com • Pure Fantom on server side • Runs on built-in Fantom web server • Developed in 4 man- months
43. Ready to be involved? • http://fantom.org • http://xored.com/f4 • mailto:fan-dev@xored.com Meet @ chill-out