Agenda

•  Apparel  Cloud  – Cloud  pla.orm  for  apparel  industry  

•  Scala  – Scala  in  model-­‐driven  development  – Scala  in  cloud  pla.orm  architecture  – Scala  features  in  real  system  development  

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Vision  for  EverforthPla.orm

Web •  UX,  IA(InformaEon  Architecture)

•  Document  DB

Computer  Science •  FP,  Logic •  Concurrent,  Parallel,  Distributed

•  Columnar  DB

Enterprise •  OOAD,  Data  Modeling,  Business  Modeling,  SOA

•  OLTP,  OLAP •  RDBMS

Everforth  Framework

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ApplicaEon  Building

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Scala

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My  Scala  Products •  Goldenport  

–  ApplicaEon  Framework  –  hRps://github.com/asami/goldenport  

•  SmartDox  –  Document  processing  system  –  hRps://github.com/asami/smartdoxprocessor  

•  SimpleModeler  –  Model  compiler  –  hRps://github.com/asami/simplemodeler  

•  g3  (experimental)  –  Server-­‐side  applicaEon  framework  –  hRp://code.google.com/p/goldenport3/  

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Everforth  Scala  Products

•  EverforthModeler  – Model  Compiler  for  EverforthFramework  and  Web  UI  Framework  

– Based  on  SimpleModeler  •  EverforthFramework  – Cloud  Service  Framework  – Derived  from  g3  experience  

•  Web  UI  framework  –  JavaScript  &  Scala  (Server  side)  

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Develop  Environment •  IDE:  Emacs  +  ensime  •  Scala  2.9.1  •  sbt  0.11.3  •  Scalatest  1.6.1  •  Play  2.0.4  (JSON,  Anorm)  

–  play20.auth  0.5  •  Scalaz  6.0.4  •  Scala  IO  0.4.0  •  Squeryl  0.9.5-­‐2  •  Scalaj-­‐Eme  0.6  •  Google  guava  14.0-­‐rc3  (Java)  

–  Concurrent  weak/sof  reference  cache  •  Typesafe  Config  1.0.0  (Java)  

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Scala  is  not  'beRer  Java'

•  Trait  •  Case  class  •  Monad  •  Type  class  •  DSL  – embedded  DSL  and  external  DSL  

•  Actor  (concurrent)  •  Future  Monad  (concurrent/parallel)  

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OOP  vs.  FP •  Our  approach:  

–  OOP  is  dominant  paradigm  in  our  development  •  Large  scale  sofware  development,  •  CollaboraEon  with  business  modeling  in  OOAD  

–  OOP  over  FP  •  Even  though    FP  is  very  comfortable  in  coding  for    model  compiler  and  server  side  frameworks.  

–  Tree/graph  structure  transformaEon  –  Parser  combinator  for  external  DSL  –  FP  over  ImperaEve  programming  –  Using  FP  in  OO  Paradigm  

•  OOP  &  FP  (and  syntax  sugers)  strongly  supports  Embedded  DSL    

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Trait

•  Trait!  Trait!  Trait!    •  trait  vs.  abstract  class  – Now,  abstract  class  is  not  used  so  much  to  me.  

•  Cake  paRern  –  (Type-­‐safe)  Dependency  InjecEon  

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Case  class •  (almost)  algebraic  data  structure  •  Nevertheless,  case  class  can  be  used  with  OOP's  polymorphism  (very  very  comfortable)  

•  Coding  strategy:  case  class  should  be  immutable  object  

•  Useful  features  with  DSL  – Default  parameter  –  copy  constructor  –  Implicit  parameter  

•  PaRern  Matching!    

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Try

•  Big  enhancement  in  2.10  •  Monad!  (i.e.  flatMap  method)  •  "Try"  everywhere  (instead  of  Either  or  scalaz.ValidaEon)  

•  required  feature  in  actor  programming  to  convey  error  state  

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Monadic  programming •  Scala  Standard  

–  Functor  –  Monad  

•  Scalaz  –  Monoid  –  ApplicaEve  Functor  –  Traverse  

•  Handling  excepEon  state  as  Try  monad  instead  of  throwing  ExcepEon.  

•  Monadic  programming  features  like  ApplicaEve  Functor,  Traverse  are  very  useful.  

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Concurrent/Parallel •  Features  

–  Actor/Akka  –  Scalaz  Promise  –  Scala  2.10  Future  and  Promise  –  Scala  2.10  Try  –  Parallel  CollecEon  

•  Techniques  –  Algebraic  datatype  

•  case  class  –  Persistent  data  structure  

•  List,  Vector  •  Scalaz  Tree  

–  ConEnuous  passing  style  

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Conclusion

•  Scala  is  a  suitable  language  for  – Model-­‐Driven  development  – Building  cloud  pla.orm  frameworks

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