[REBOL] Objects, references & values
From: robert::muench::robertmuench::de at: 18-Dec-2001 12:41
Hi, up to now I mostly used Rebol to handle some simple structured data. Now I
want to use datastructures to handle more complext data and there I have some
problems with. Please keep in mind that I'm an old C++ programmer and might not
have switched my mind to see datastructures the rebolized way.
Here is my test proggy:
Rebol[]
myobj!: make object! [
name: string! 0
note: string! 0
]
myobjects1: make hash! []
myobjects2: make hash! []
obj1: make myobj! [name: "Robert" note: "Rebol"]
; this is an obj1 reference
insert myobjects1 reduce [1 obj1]
; this is the value obj1/name
insert myobjects2 reduce [obj1/name 1]
; this is the value obj1/name
value: obj1/name
?? obj1
?? value
?? myobjects1
?? myobjects2
; changing the object obj1 and all of its references
obj1/name: "robert"
?? obj1
?? value
?? myobjects1
?? myobjects2
halt
As you can see, if I reference object-words, I get the value and not the
reference to the origianl value. For the C++ developer this means:
using obj1 somewhere gives me a pointer
using obj1/<some-obj1-member> gives me the value
How can I create datsstructures with objects if I can't get references to the
original object all the time? I want to have one single object being the base
and than use references to the object or parts of it all over my script. Any
idea?
IMO the concept of a get-path is missing. I would like to write:
value: to-get-path obj1/name
This should result in a reference to obj1/name and not the value.
--
Robert M. Münch
IT & Management Freelancer
Mobile: +49 (0)177 2452 802
Fax : +49 (0)721 8408 9112
Web : http://www.robertmuench.de
