OpenEuphoria

Re: Architectural Discussion: Implementing ECS and Data-Oriented Programming (DOP)

• Posted by jmduro 3 weeks ago
• 195 views

Five years ago, I proposed a way to do OOP-like programming using OEU's preprocessor.

Here is its test example, test_classes.oex:

include builtins\timedate.e   
 
function get_years(atom secs) 
  atom days = floor(secs/86400) 
  return floor(days/365.25) 
end function 
 
class person 
  public timedate birth_date = date() 
  public sequence birth_place = "" 
  public sequence mother_tongue = "" 
  procedure describe() 
    atom secs = timedate_diff(this.birth_date, date()) 
    printf(1, "\nHello! I speak %s.\n", {this.mother_tongue}) 
    printf(1, "I am %d years old. I was born in %s.\n", {get_years(secs), this.birth_place}) 
  end procedure 
 
end class 
 
person englishman = new() 
englishman.birth_date = parse_date_string("May 14 2010",{"Mmmm d yyyy"}) 
englishman.birth_place = "Liverpool" 
englishman.mother_tongue = "english" 
 
person frenchman = new() 
frenchman.birth_date = parse_date_string("August 10 1960",{"Mmmm d yyyy"}) 
frenchman.birth_place = "Thionville" 
frenchman.mother_tongue = "french" 
 
person german = new() 
german.birth_date = parse_date_string("February 11 1993",{"Mmmm d yyyy"}) 
german.birth_place = "Munich" 
german.mother_tongue = "german" 
 
englishman.describe() 
frenchman.describe() 
german.describe() 
 
maybe_any_key() 

It converted this code to OEU code, test_classes.ex:

include std/datetime.e 
include std/console.e 
include classes.e 
 
------------------------------------------------------------------------------ 
 
function get_years(atom secs) 
  atom days = floor(secs/86400) 
  return floor(days/365.25) 
end function 
 
------------------------------------------------------------------------------ 
 
function describe(sequence entity, sequence params) 
  atom secs = diff(getProperty(entity, "birth_date"), now()) 
  printf(1, "\nHello! I speak %s.\n", {getProperty(entity, "mother_tongue")}) 
  if length(params) then 
    printf(1, "I am %d years old. I was born in %s (%s).\n", {get_years(secs), getProperty(entity, "birth_place"), params[1]}) 
  else 
    printf(1, "I am %d years old. I was born in %s.\n", {get_years(secs), getProperty(entity, "birth_place")}) 
  end if 
  return 0 
end function 
 
------------------------------------------------------------------------------ 
 
procedure main(sequence cmd) 
  object void 
 
  sequence TPerson = class("TPerson") 
  TPerson = addProperty(TPerson, "birth_date", now()) 
  TPerson = addProperty(TPerson, "birth_place", "") 
  TPerson = addProperty(TPerson, "mother_tongue", "") 
  TPerson = addMethod(TPerson, "describe", routine_id("describe")) 
 
  sequence englishman = classes:new(TPerson) 
  englishman = setProperty(englishman, "birth_date", datetime:new(2010, 5, 14)) 
  englishman = setProperty(englishman, "birth_place", "Liverpool") 
  englishman = setProperty(englishman, "mother_tongue", "english") 
 
  sequence frenchman = classes:new(TPerson) 
  frenchman = setProperty(frenchman, "birth_date", datetime:new(1960, 8, 10)) 
  frenchman = setProperty(frenchman, "birth_place", "Thionville") 
  frenchman = setProperty(frenchman, "mother_tongue", "french") 
 
  sequence german = classes:new(TPerson) 
  german = setProperty(german, "birth_date", datetime:new(1993, 2, 23)) 
  german = setProperty(german, "birth_place", "Munich") 
  german = setProperty(german, "mother_tongue", "german") 
 
  void = callMethod(englishman, "describe", {"Merseyside"}) 
  void = callMethod(frenchman, "describe", {"Lorraine"}) 
  void = callMethod(german, "describe", {"Bavaria"}) 
end procedure  -- main 
 
------------------------------------------------------------------------------ 
 
-- Main 
main(command_line()) 
maybe_any_key() 

I don't remember all the details. I will rework this to make it run again.

Jean-Marc