OpenEuphoria

Re: Data hiding

• Posted by Igor Kachan <kinz at pet?rlink.ru> Oct 19, 2007
• 593 views

Matt Lewis wrote:
> 
> Igor Kachan wrote:
> > 
> > To resolve the examples like to above one, I'd suggest some
> > new parameter for the "as" metacommand - "sublibrary":
> > 
> }}}
<eucode>
>    include lib_a.e as sublibrary -- all globals of lib_a.e
> </eucode>
{{{

> > I think, we can implement some useful things using new
> > parameters for old good key words 'with', 'without' and 'as'.
> > For now, I do not see any need of new keywords in Euphoria.
> > 
> > > I'd be interested in hearing from people other than us 3. :)
> > 
> > OK, did you listen to me, may I continue ?    
> 
> It's a good idea in that it doesn't create any new keywords.  My only
> concern is that we're overloading the 'as' usage of include.  
> Obviously, you couldn't have a namespace called sublibrary.  How would
> you namespace something that was included as a sublibrary?
> 
> The with/without directives are easier to add functionality to since their
> next parameter defines the functionality by definition.  Here, you've 
> changed the as keyword.  It's easy enough to implement into the parser,
> but I think it's not obvious that you're not just assigning a namespace.
> 
> Maybe something like:
> }}}
<eucode>
>   include as private lib.e as lib
> </eucode>
{{{

> 
> The difference being that the placement of 'as' changes its meaning, rather
> than simply what comes after.  I think I like 'private' over sublibrary.
> It's a bit more direct and connected with what its really doing.  But
> this syntax seems to stand out more to me than changing 'include' to 
> 'import.'

Ok, I do not like very much that "sublibrary" too.

Maybe just "$" is better here.

Say:

include lib_a.e as $ -- we see only its own globals
include lib_a.e as $A -- we see only its own globals with prefix A:
include lib_a.e as $B. -- we see only its own globals with pefix B.
include lib_a.e as C   -- we see all its globals (current syntax)
include lib_a.e as $D without EE -- we do not see just EE

The "$" sign already is reserved in Euphoria, so it can
be used in other contexts with some new duty and sense.

About "private" word I can say -- it is already used in
Euphoria documentation for saying about the hidden
*inner variables* of routines, so it seems to be not
very good to tell about *global* things.

Regards,
Igor Kachan
kinz at peterlink.ru