[gambit-list] How to handle and access and interact with object members host code

ben yakawp ben.lists at yakawp.com
Mon Dec 7 11:44:18 EST 2015


Just to be a little more precise. Expressing OO style in Scheme was not
my primary concern here. The problem I see is that the all of the host
languages (except the original C backend) access their library functions
through an OO interface. It's not like the library approach in scheme
were you can directly use a function after you imported it.

That means if you want to use a function from a host language you first
have to create an object. But now what is this object in Scheme and what
can it do? In the best case, it would check the member calls at compile
time. In the worst case it add runtime cost in the backend.

But thats just stuff I was thinking about. 

What I wanted to know in the first place is how I should accessing
backing library functions / ffing that are "hidden" behind OO apis. 
How is this done?


On Mon, Dec 7, 2015, at 05:13 PM, Marc Feeley wrote:
> At the Scheme level, you can express the OO style in various ways.  Here
> are 2 that come to mind:
> 
> 1) Your “new” operator could return a closure which receives as a first
> parameter the name of the method to be called.  So you could:
> 
> (define o (new Lib))
> (o print: "hello")
> 
> or
> 
> (define .print '.print)
> (o .print "hello")
> 
> 2) You could make .print a function that receives as a first parameter
> the object on which the method applies.  For example:
> 
> (define .print (lambda (self text) …))
> (define o (new Lib))
> (.print o "hello")
> 
> You can of course use macros to automate these styles.
> 
> Marc
> 
> > On Dec 7, 2015, at 8:31 AM, ben yakawp <ben.lists at yakawp.com> wrote:
> > 
> > hi
> > Sorry if this too obvious, but I don't understand how gambit handles
> > objects from the hosts backend.
> > 
> > 
> > For example: if one would like to construct a 'Node' library for the JS
> > backend, how would you do that? The whole node api seems to be object
> > oriented.  But also the Python standard libaries (batteries) are layed
> > out class based. You had to do something like
> > 
> > (define o (new Lib))
> > (o.print "hello")
> > 
> > This looks wrong. What am I missing?
> > 
> > Regards
> > ben
> > _______________________________________________
> > Gambit-list mailing list
> > Gambit-list at iro.umontreal.ca
> > https://webmail.iro.umontreal.ca/mailman/listinfo/gambit-list
> 


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