[REBOL] [REBOL] [REBOL] Redefining functions with objects Re:(4)
Hi Ingo: In reply to your statement: When your 'op was named 'open, did you change the line fp: open/new/write %objone.txt to fp: system/words/open/new/write %objone.txt - ?? otherwise it has called itself, again and again ... I didn't - and that's why I got a stack overflow, because of unending recursion. Thanks! I'm glad you caught that! Tim At 01:20 PM 4/12/00 +0200, you wrote: Hi Tim, I haven't closely looked at your code, but a short notice on ... Those were the words of [EMAIL PROTECTED]: I have probably answered my own question: I'm still a newbie, but am pleased to return results - ; == consider the following code: the two objects work ; independently. They use the same named methods ; op, prn, and close ; When I named those methods open, print,and close, ; I got stack overflows, which suggests to me ; that rebol doesn't like me overridding their ; own system functions. ... object-one: make object! [ op: func [] [fp: open/new/write %objone.txt] prn: func [value] [append fp value] cls: func[] [close fp] ] -- _ ._ ingo@)|_ /| _| _ We ARE all ONE www._|_o _ _ ._ _ www./_|_) |o(_|(/_ We ARE all FREE ingo@| |(_|o(_)| (_| http://www.2b1.de/Rebol/ ._| ._|
[REBOL] [REBOL] Redefining functions with objects Re:
Hi Tim, Will tims-object/print redefine rebol's own print? Within tims-object print replaces the global print, which you can continue to access using system/words/print tims-object: make object! [ print: func [][ system/words/print "this is the global print." ] ] tims-object/print this is the global print. Outside of the object's context print is not affected by your re-definition of print in the object. ;- Elan [: - )]
[REBOL] [REBOL] Redefining functions with objects Re:(2)
Hi Michael -
At 12:42 PM 4/11/00 -0700, you wrote:
I'm currently defining a 'print element of an object as a function. I'm
assuming that the REBOL definition of 'print will be hidden in the
definition of this object (and definitions of functions local to the object)
Actually .
print would write to a port, which could be standard
output OR a physical file. The port would be defined
as a member of the object as well.
let's call this content-object ; will build virtual
; pages OR could be used to build a physical web page
; let me know what you think of the following:
; thanks for your interest :)
; tim
content-object: make object!
[
write_to_file: func []
[
; is this being run from a server?
either equal? system/options/cgi/server-name none
[return true]
[{else}return false]
]
init_output: func[fname[string!] /local fpl]
[
either write_to_file ; no server so open a write port
; to fname
[
file_name: make file! fname
fp1: open/new/write file_name
]
; yup, we're on the server so keep writing to stdout
[{else} fp: system/ports/output]
return fpl
]
; what the hay!! We can call this anything, but
; print would be great if it didn't screw up implicit
; output to stdout for the "original print"
fp: init_output "hello.htm"
print: func [fp[port!] value]
[append fp value]
]
; If this process works with out conflict, then I would
; create a debug object which would write to a file that
; would be created every time the application runs
; and an errorlog object that would be appended every
; time the application ran, given an error or warning
; condition appeared. Standard parts of the my C/C++/CGI
; toolkit and expected by sysops that my cgi programs
; run on. They could all have a print element (method)
; OR I could call it something else.
- which is ok. Outside of the element 'print, the REBOL definition works
just fine. Following is the relevant piece of my object:
player-def: make object! [
name: none
connection: none
; METHODS
; - - - - - - - - - - - - - - - - - - - - - -
print: function [
"Print a message to this player, with trailing new-line"
msg [string! block!]
][new-msg][
; Cleanup the message suitable for telnet display
new-msg: player-format-print msg
append new-msg new-line
append connection new-msg
]
; - - - - - - - - - - - - - - - - - - - - - -
prin: function [
"Print a message to this player"
msg [string! block!]
][new-msg][
; Cleanup the message suitable for telnet display
new-msg: player-format-print msg
append connection new-msg
]
]
- Michael Jelinek
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, April 11, 2000 11:32 AM
To: [EMAIL PROTECTED]
Subject: [REBOL] [REBOL] Redefining functions with objects
I'm thinking of developing a class.
Let's call it
tims-object
Suppose I write a function for this
class and I call it
print
Will
tims-object/print
redefine rebol's own print?
I don't really want to do this, so
I would welcome comments on this.
thanks
tim
[REBOL] [REBOL] [REBOL] Redefining functions with objects Re:(2)
I have probably answered my own question:
I'm still a newbie, but am pleased to return
results -
; == consider the following code: the two objects work
; independently. They use the same named methods
; op, prn, and close
; When I named those methods open, print,and close,
; I got stack overflows, which suggests to me
; that rebol doesn't like me overridding their
; own system functions.
; I'm happy with the result. Less typing eh!
REBOL
[
Title: "object"
Date: 011-Apr-2000
File: %object.r
Purpose: {testing rebol objects}
]
;=== make first object
object-one: make object!
[
op: func [] [fp: open/new/write %objone.txt]
prn: func [value]
[append fp value]
cls: func[] [close fp]
]
;=== make first object
object-two: make object!
[
op: func [] [fp: open/new/write %objtwo.txt]
prn: func [value]
[append fp value]
cls: func[] [close fp]
]
;=== test first object
object-one/op
object-one/prn "testing object-one once more"
object-one/cls
;=== test second object
object-two/op
object-two/prn "testing object-two once more"
object-two/cls
At 05:10 PM 4/11/00 -0800, you wrote:
Hi Michael -
At 12:42 PM 4/11/00 -0700, you wrote:
I'm currently defining a 'print element of an object as a function. I'm
assuming that the REBOL definition of 'print will be hidden in the
definition of this object (and definitions of functions local to the
object)
Actually .
print would write to a port, which could be standard
output OR a physical file. The port would be defined
as a member of the object as well.
let's call this content-object ; will build virtual
; pages OR could be used to build a physical web page
; let me know what you think of the following:
; thanks for your interest :)
; tim
content-object: make object!
[
write_to_file: func []
[
; is this being run from a server?
either equal? system/options/cgi/server-name none
[return true]
[{else}return false]
]
init_output: func[fname[string!] /local fpl]
[
either write_to_file ; no server so open a write port
; to fname
[
file_name: make file! fname
fp1: open/new/write file_name
]
; yup, we're on the server so keep writing to stdout
[{else} fp: system/ports/output]
return fpl
]
; what the hay!! We can call this anything, but
; print would be great if it didn't screw up implicit
; output to stdout for the "original print"
fp: init_output "hello.htm"
print: func [fp[port!] value]
[append fp value]
]
; If this process works with out conflict, then I would
; create a debug object which would write to a file that
; would be created every time the application runs
; and an errorlog object that would be appended every
; time the application ran, given an error or warning
; condition appeared. Standard parts of the my C/C++/CGI
; toolkit and expected by sysops that my cgi programs
; run on. They could all have a print element (method)
; OR I could call it something else.
- which is ok. Outside of the element 'print, the REBOL definition works
just fine. Following is the relevant piece of my object:
player-def: make object! [
name: none
connection: none
; METHODS
; - - - - - - - - - - - - - - - - - - - - - -
print: function [
"Print a message to this player, with trailing new-line"
msg [string! block!]
][new-msg][
; Cleanup the message suitable for telnet display
new-msg: player-format-print msg
append new-msg new-line
append connection new-msg
]
; - - - - - - - - - - - - - - - - - - - - - -
prin: function [
"Print a message to this player"
msg [string! block!]
][new-msg][
; Cleanup the message suitable for telnet display
new-msg: player-format-print msg
append connection new-msg
]
]
- Michael Jelinek
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, April 11, 2000 11:32 AM
To: [EMAIL PROTECTED]
Subject: [REBOL] [REBOL] Redefining functions with objects
I'm thinking of developing a class.
Let's call it
tims-object
Suppose I write a function for this
class and I call it
print
Will
tims-object/print
redefine rebol's own print?
I don't really want to do this, so
I would welcome comments on this.
thanks
tim
