it was finally christmas: perl 6 is here!
TRANSCRIPT
ItwasfinallyChristmas: Perl6ishere! WimVanderbauwhede SchoolofCompu6ngScience UniversityofGlasgow
“Languageisideology”
Kress,Gunther,etal."Languageasideology."(1982).
Atripdownmemorylane
2007
• Perl6/PugsinvitedtalkatPOPL2007• AudreyTanghadcreatedPugs,aPerl6
implementa6oninHaskell• Perl6waspromisedfor"Christmas”• Andtherewassomedelay…
Perl6meline
DowJonesindex,1985-2015
Context
hZp://www.codeeval.com/
Context
TIOBEIndexforFebruary2016,hZp://www.6obe.com/
Popularityofprogramminglanguages–TIOBE
Context
TIOBEIndexforFebruary2016,hZp://www.6obe.com/
Popularityofprogramminglanguages–TIOBE
Perl
NeilStephenson,“Cryptonomicon”,p480
Perl5
• Interpreted• Dynamicallytyped• Garbagecollec6on• InthatsenseverysimilartoJavaScript,Python,Ruby,…
Perl5
• Usesfunnycharactersfortyping:$:scalar@:array(list)%:hash(dic6onary,map)&:subrou6ne
• Incorporatesaseparatelanguage:regularexpressions(PCRE)
Perl5
• Butalso:• Lexicalscoping• Higher-orderfunc6ons• Anonymousfunc6ons• Closures
Perl6
• Isanewlanguage,notbackwardcompa6blewithPerl5.
• S6llmostlyPerl• Butamodernlanguage
CompilerandVM
Compiler(Rakudo)
hZps://github.com/rakudo/rakudo
VM(MoarVM)
• Meta-objectprotocolbased• Precise,genera6onal,andparallelGC• First-classcodeobjects,closures,…• Excep6ons• Con6nua6ons• Threads,mutexes,…• JITcompila6onhZps://github.com/MoarVM/MoarVM
Grammars
Parsing
• Perl6hasGrammars,Rules,TokensandRegexesaspartofthelanguage• Similartoclassesbutusedtoorganizeparsers
• Rulesarelexemeparsers• Tokensaretokenparsers• RegexesarePCREs
• Perl6isparsedandexecutedusingaPerl6-stylegrammar.
Objects
JavaScript
Python
Objects
Perl6Objects
Perl6Objects
Roles
Perl6Objects
• Accessorsforfree
• Defaultconstructor • Inheritance• Roles(mixins) • BuiltonaMetaObjectProtocol• Fullintrospec6on• Sos6llnothingspecial…
Butwait…
Perl6Objects
Perl6Objects
Gradualtyping!
Gradualtyping
• Bydefaultvariablesaredynamicallytyped.• Explicitlytypedvariablesaresta6callytyped.• Buttypecheckscanbedeferredtorun6me.• Underlyingtheory:
hZps://github.com/samth/gradual-typing-bib
Gradualtyping:subsets
• Typeconstraintcheckedatrun6me
Gradualtyping:typecapture
• Deferthespecifica6onofatypeconstrainttothe6methefunc6oniscalled.• Allowstorefertoatypebothinthesignatureandthefunc6onbody.
Gradualtyping:typecapture • Deferthespecifica6onofatypeconstrainttothe6methefunc6oniscalled.• Allowstorefertoatypebothinthesignatureandthefunc6onbody.
Roles
Roles
• BasisforthePerl6typesystem• Usedforcomposi6onandmixins• InPerl6,the“funnycharacters”aresyntaxforasetofpredefinedroles:
@:Posi6onal(array)%:Associa6ve(hash)&:Callable(subrou6ne)
• So…
Nomorefunnycharacters!
• Actually,the“funnycharacters”arenowop6onal:
Polymorphicfunc6ons
• Alsoknownasmul6pledispatch
Polymorphicfunc6ons
• Alsoknownasmul6pledispatch
Polymorphicfunc6ons
• Looksfamiliar?
Parametricroles
• Rolesthattakeoneormoretypevariables
PossiblyMaybe
FuncHonalprogramming
Func6onalfeatures
• Higher-orderfunc6ons• Anonymousfunc6ons(lambdas)• Currying• Immutablelists,lazyevalua6on• Tailcallop6miza6on• Op6onalimmutablevariables
Typecapturerevisited
• Typecapturealsoworkswithclosuresandlambdas
Lazylists
• Perl6dis6nguishesbetweensequences,listsandarrays.
• Sequencesareimmutable,butareconsumedwheniterated.• Listsareimmutable• Arraysaremutable
• BydefaultsSeq,ListandArrayarelazy,butcanbemadeeager.
SeqandList
Array
Promises
Concurrency
• High-level• Promises(futures)• Channels• Supplies
• Low-level• Threads• Schedulers• Locks
Promises
Conclusion
•
Thank you!