OpenEuphoria

1. public, export

• Posted by jiri Mar 15, 2009
• 994 views

The new version of 4.0 docs is pretty good already. Even the section dealing with scopes has been improved, but one thing is still puzzling me: the difference between public and export, if any. These terms seem to be used interchangeably in the libraries. If they are indeed synonyms, why do we have to have such stupid, misleading duplicity, well, I mean duplication? (Sorry, English is only my third language...)

jiri

3. Re: public, export

• Posted by jeremy (admin) Mar 15, 2009
• 983 views

The Scope section of the manual goes into this a little. It should be expanded a bit to include some examples to better show it's reasoning. During the beta stages we are going to really focus on creating more unit tests and enhancing the docs more.

Jeremy

5. Re: public, export

• Posted by jeremy (admin) Mar 15, 2009
• 980 views

A simple example right now:

-- button.e 
export function button_class_id()  
    return "Button" 
end function 
 
public function button_new(sequence name) 
    -- make new button 
    return button 
end function 
 
-- window.e 
export function window_class_id()  
    return "Window" 
end function 
 
public function window_new(sequence name) 
    -- make new window 
    return window 
end function 
 
-- gui.e 
public include button.e as but 
public include window.e as win 
 
? button_class_id() -- Good! 
? window_class_id() -- Good! 
 
-- myprog.ex 
include gui.e 
 
object w = window_new("Hello World!")  -- Good! 
object b = button_new("Press Me")      -- Good! 
 
? window_class_id() -- Unknown Function! 
? button_class_id() -- Unknown Function! 

See, the *_class_id() methods are used internally for the multi-file GUI library. They are not meant to be used by the user, nor should the user be relying on them. Their implementation/functionality may very well change over time. So, the export keyword allowed those functions to be exposed to those who directly included button.e or window.e, but their availability was not passed on when gui.e did a public include button.e or public include window.e.

Jeremy