OpenEuphoria Next

See also https://openeuphoria.org/forum/135932.wc
by mitgedanken

Class and Interface

See also Module

Q&A

I prefer instancible modules because `module` is a known concept of Euphoria.
So this is an extension instead of something completly new. In addition, modules are more flexible.
You can also define an interface as well as many other things,
such as complex structures.

Class

Define

class Name 
 
  -- private by default - accessible by this class, only! 
  integer a = 0 
  constant B = {"blah", ' '} 
 
  -- can be accessed by an class or module 
  export sequence w = "Hello World" 
   
  -- can be accessed from a class that extends this class. 
  public integer b = 1.3 
 
  -- This routine must exist only once if its 
  -- parameters are the same (or if none are defined). 
  -- Must not be called! - it's private and not callable. 
  --- 
  -- The program code shown is similar to the standard implementation. 
  --- 
  new(integer number) 
    self.a = number -- or a = number 
  end new 
 
  -- This routine must exist only once. 
  -- Must not be called! - it's private and not callable. 
  --- 
  destroy() 
    ... 
  end destroy 
 
  -- This routine must exist only once. 
  -- The program code shown is similar to the standard implementation. 
  -- Must not be called! - it's private and not callable. 
  --- 
  failed (integer errorcode)  
      puts(STDERR, "Error; code " + errorcode) 
  end failed 
   
  ... 
 
  --- 
  -- as normal 
 
  function x() 
    ... 
  end function 
 
  procedure y() 
    ... 
  end procedure 
 
end class 

Use

  instance C = new Name() 
  -- may be @Class C = ... ?! 
  c.x() 
  sequence b = c.w -- or c#w 
  constant p = c.B -- or c##B => must throw an error ('Constant `B` is private') 

Interface

Define

Interface's routines are public by default! And an error must be thrown if visibility is defined (private, export, public)

interface Animal 
 
   function name() 
     ... 
   end function 
 
end interface 

Use

with class

class Tiger is Animal 
  ... 
end class 

instance tiger = new Tiger() 
if tiger instanceof Animal then 
  -- is true 
end if 

with instancible module

module Tiger is Animal 
  ...