Talk given at Agiles 2011, Argentina

1. The Technical Debt of the Programming Languages … and the influence in our designs Hernán Wilkinson – Jorge Silva Agile 2011

2. Fuente: http://c2.com/cgi/wiki?WardExplainsDebtMetaphor Technical Deb Metaphor… Debt Speed Burden Agility … if we failed to make our program align with what we then understood … write code that is clean enough to be able to refactor as you come to understand your problem With borrowed money you can do something sooner than you might put that learning back into the program

10. aTrafficLight northSouthController eastWestController

11. aTrafficLight rightController leftController

12. aTrafficLight controller1 controller2

20. To avoid REPETITION To provide MEANING to that REPETITION

35. List<Customer> selectedCustomers = new ArrayList<Customer> (); for (Customer customer: customers) if (customer.nameStarsWith(“H”)) selectedCustomers.add (customer); return selectedCustomers; List<Account> selectedAccounts = new ArrayList<Account> (); for (Account account: accounts) if (account.isOverdraw()) selectedAccounts.add(account); return selectedAccount; cutomers.select( customer => customer.nameStartsWith(“H”) ) accounts.select( account => account.isOverdraw() )

41. cutomers reject: [ :aCustomer | aCustomer nameStartsWith: ‘H’ ] (Smalltalk) customers.reject { | aCustomer | aCustomer.nameStartsWith(“H”) } (Ruby) customers.Where( aCustomer => !aCustomer.nameStarsWith(“H”)) (C#) reject List<Customer> selectedCustomers = new ArrayList<Customer> (); for (Customer customer: customers) if (!customer.nameStarsWith(“H”)) selectedCustomers.add (customer); return selectedCustomers;

42. List<Customer> selectedCustomers = new ArrayList<Customer> (); for (Customer customer: customers) if (customer.nameStarsWith(“H”)) return customer; throw …. customers detect: [ :aCustomer | aCustomer nameStartsWith: ‘H’ ](Smalltalk) customers.detect { | aCustomer | aCustomer.nameStartsWith(“H”) } (Ruby) customers.First ( aCustomer => aCustomer.nameStarstWith(“H”)) (C#) detect

43. customers collect: [ :aCustomer | aCustomer name ] (Smalltalk) customers.collect { | aCustomer | aCustomer.name () } (Ruby) customers.Select( aCustomer => aCustomer.name() ) (C#) collect List<String> customerNames = new ArrayList<String> (); for (Customer customer: customers) customerNames.add (customer.name()); return customerNames;

44. self should: [ do something ] raise: Exception withExceptionDo: [ :e | self assert: …. ] (Smallalk) C# Does not have one that I’m aware of … TDD: Test for exceptions Try { … do something fail() } catch (Exception e) { assertTrue (…. ) }

57. Technical Deb Quadrant Fuente: http://martinfowler.com/bliki/TechnicalDebtQuadrant.html

60. Questions?