[REBOL] Dynamically Modifying objects!
From: edanaii:cox at: 21-Feb-2003 16:03
All,
About a month ago, I asked if it were possible to dynamically modify an
object. I got various answers, all good, btw, but all indicating that it
is not a built-in part of the language.
I decided to revisit the problem and here is my solution.
======================================================================
REBOL [
File: %Malleable.r
Date: 20-Feb-2003/15:44:54-7:00
Title: "Make Malleable Object"
Name: "Malleable Object"
Version: 1
Author: "Ed Dana"
Usage:
{* Create - Test: Make Malleable! [ Name: "Will Robinson" ]
* Add - Test: Test/_Add [ Status: "Lost in Space" ]
* Remove - Test: Test/_Remove [ 'Status ]
* Display- Test/_Data
}
Purpose: "Allows data do be added to an object dynamically."
Type: 'Misc
]
Malleable!: make object! [
_Add: func [Data [block!]][
Make Self Data
]
_Class: 'Malleable
_Data: func [/Local Blk Str][
Blk: Make Block! 0
ForEach Item Next First Self [
Str: To-String Item
If Str/1 <> #"_" [
Append Blk Item
]
]
]
_Remove: func [Minus [word! block!] /Local Str][
If Type? Minus = 'Word [Minus: To-Block Minus]
Str: Make String! 0
ForEach Item Self/_Data [
If Not Find Minus Item [
Str: Rejoin [Str " " Item ": " Mold Get In Self Item]
]
]
Make Malleable! To-Block Str
]
]
======================================================================
It works as follows:
--> Create <--
>> Contact: Make Malleable! [ Name: "Fred Flintstone" ]
>> Contact/_Data
== [Name]
>> Contact/Name
== "Fred Flintstone"
--> Add <--
>> Contact: Contact/_Add [ Address: "32 E. Deer Trail" Status:
Hanna-Barbaric
Phone: "Shout!" ]
>> Contact/_Data
== [Name Address Status Phone]
>> Contact/Name
== "Fred Flintstone"
>> Contact/Address
== "32 E. Deer Trail"
>> Contact/Status
== "Hanna-Barbaric"
>> Contact/Phone
== "Shout!"
--> Remove <--
>> Contact: Contact/_Remove 'Status
>> Contact/_Data
== [Name Address Phone]
>> Contact/Status
** Script Error: Invalid path value: Status
** Near: Contact/Status
Feel free to question, comment, criticize or even offer tips. :)
--
Sincerely, | We're Human Beings, with the blood of a million
Ed Dana | savage years on our hands! But we can stop it! We
Software Developer | can admit we're killers, but we're not going to
1Ghz Athlon Amiga | kill today. That's all it takes! Knowing that we're
| not going to kill... Today! -- Shatner, Star Trek.
