about having something similar to the extend attribute ?

zwetan zwetan at gmail.com
Mon Jan 8 11:47:32 PST 2007


On 1/8/07, Peter Hall <peterjoel at gmail.com> wrote:
> Do you see any practical advantage of this over just using static or
> package-level methods and passing an instance as an argument?
>

yes, all these advantages:

- being able to augment buildins classes with new behaviours
  basic example of scramble/unscramble
  most of people will not care to have those methods for general use
  but someone doing a lot of programming with games having to scramble
  text will be happy to have this features directly in the String class

- less typing, better naming convention
  example:
  I love the String.Format() method in C#
  it s well named, make perfect send to have it defined in the String class
  and it's more than usefull for formatting text
  I want to have the same method in ES4 because I can not live without it
  what are the options now ?

  -> defining a static in a StingUtil lib
      sorry but String.format() is a better naming scheme imho
  -> compiling in standard mode and adding the method to the String class object
      we loose all the good things of strict mode (the speed of Tamarin VM :))
  -> harassing TG1 till they include it by default in ES4 (unlikely to succeed)

  I think that till you don't want to override something already defined
  you should be allowed to add to it
  adding String.format -> good, harm no one
  changing String.replace -> bad, people will expect the standard behaviour

  It follow the same logic, from ES3 to ES4
  Array got new methods
  String got new methods
  etc..
  people were adding it to the prototype because they were usefull

  ES4 committee will never have the time to define and implement
  a ES4 framework (meaning going beyond the buildin classes)
  as what we have in Java or .NET
  and mind me that's not necessary to have
  but still if some people want to implement such things
  a kind of extend attribute will be more than welcome I think


- clean API easyly extensible

  use case:
  you distribute a library as bytecode (abc)
  people can still extend it even without the source code

  the library is extensible but you can not break it or change its behaviour
  but you can add behaviours / utilities / addon / etc..

  example:
  using tons of third party libraries (closed source or not)
  one could easyly add a toSomething method to all the objects
  for ex toXML, toJSONString, etc..

- it allows you to add your own namespace to an existing class
  without touching / modifying the internal of this class

  use case:
  dynamic programming to its best
  why agregate, inherit etc.
  when you just want to patch things up
  in a certain context or at a certain moment

  example:
  with the class Number, Int, Uint, Math
  one could add a Big namespace to those buildin classes
  and so could compute big integer and big float
  -> this will not change the way numbers working by default in ES4
  -> it will allow to have a big number context in special cases
      but using standard numbers class transparently


zwetan



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