OpenEuphoria

Re: Namespace request

• Posted by Jason Gade <jaygade at yahoo.com> Feb 11, 2006
• 520 views

Al Getz wrote:
> 
> Jason Gade wrote:
> > 
> > Al Getz wrote:
> > > 
> > > Jason Gade wrote:
> > > > 
> > > > Rob, can you change namespacing so that more than one file can be
> > > > included
> into</font></i>
> > > > the same namespace?
> > > > 
> > > > Here is an example of what I want to do:
> > > > 
> > > > include misc.e as rds
> > > > include machine.e as rds
> > > > include dll.e as rds
> > > > 
> > > > Currently the interpreter gives an error.
> > > > 
> > > > Rationale: I want to use namespaces in a file that is intended to be
> > > > included
> > > > by another so as to avoid conflicts in user programs. But when I know
> > > > that
> there</font></i>
> > > > will be no conflicts within the files that I'm including I don't want to
> > > > make
> > > > a new namespace for every single include. This will also help prevent
> > > > namespace
> > > > pollution by reducing the number of unique namespaces that a program
> > > > needs to
> > > > come up with.
> > > 
> > > Hi there,
> > > 
> > > 
> > > So i guess you're saying you want to include multiple files under the
> > > same namespace so functions can be called in multiple files using
> > > the same prefix...interesting...
> > 
> > Yes. That's the way it works in C++, several related includes are part of
> > the
> > same namespace. C++ also has the 'using namespace' keyword.
> > 
> > But right now I'm looking through the listserv archives to understand better
> > how namespace rules actually work. I've noticed so far that they don't
> > exactly
> > do what I think they do.
> > 
> > So far I've found that using namespaces within a library won't prevent
> > symbol
> > conflicts in user programs, though using them might make them easier to fix.
> > The user program will still have to use a namespace when a conflict arises.
> > 
> > By my example, I don't really expect there to be a symbol conflict with RDS
> > libs, but I was trying to be "future proof" and protect the user from having
> > to worry about it.
> > 
> > --
> > "Any programming problem can be solved by adding a level of indirection."
> > --anonymous
> > "Any performance problem can be solved by removing a level of indirection."
> > --M. Haertel
> > j.
> 
> Hi again,
> 
> I guess there are good points to this and bad points, but i havent
> thought it all through myself yet.
> I wanted to be able to include the same file more than once (which
> would be easy in the source code) and have it load again so that 
> local variables get repeated:
> 
> --Start Manager.ew
>   atom a
>   global procedure LoadA(atom x)
>     a=x
>   end procedure
>   global function GetA()
>     return a
>   end function
> --End Manager.ew
> 
>   include Manager.ew as M1
>   include Manager.ew as M2
> 
>   M1:LoadA(10)
>   M2:LoadA(20)
> 
>   ?M1:GetA() --prints "10"
>   ?M2:GetA() --prints "20"
> 
> Currently, you have to copy and rename Manager.ew and included it a second
> time with it's new name
>   include Manager1.ew as M1
>   include Manager2.ew as M2
> 
> If we could include the same file twice and get a new instance loaded
> (as per code far above) we would be able to handle files as entire
> objects, which would increase the functionality of Euphoria quite a bit.
> Imagine being able to write a 'class' file as an include file that had
> all kinds of functionality including functions AND data structures,
> and in one line be able to repeat that 'object' 
>   include MyClass.ew as Class1
>   include MyClass.ew as Class2
> 
> Add to that the ability to index and WOW we've got incredible functionality:
>   Class={1,2,3,4,5}
>   for k=1 to 5 do
>     include MyClass.ew as Class[k]
>   end for
> and suddenly we can index entire classes:
>   data1=Class[1]:data
>   data2=Class[2]:data
>   etc.
> 
> WOW!!!!!!!!
> 
> 
> Al
> 
> 
> My bumper sticker: "I brake for LED's"

I really wish that it worked that way, too. I've lobbied for it in the past
(except for the include as Class[k] bit -- Beautiful! I can see all kinds of
possibilities). I think that it would provide more modularity and make OO like
you are proposing easier.

But RDS is extremely unlikely to implement it because... well because Rob likes
the way includes work now! In fact, I'm still surprised that Vincent finally got
him to give a little slack on the
includes-with-the-same-filename-but-different-paths problem.

--
"Any programming problem can be solved by adding a level of indirection."
--anonymous
"Any performance problem can be solved by removing a level of indirection."
--M. Haertel
j.