r3wp [groups: 83 posts: 189283]
  • Home
  • Script library
  • AltME Archive
  • Mailing list
  • Articles Index
  • Site search
 

World: r3wp

[Core] Discuss core issues

Henrik
7-Jan-2008
[8981]
thanks for your work.
Henrik
8-Jan-2008
[8982x2]
anyone know of a function to calculate the relative path between 
two branches in a file system?
I think I'm figuring it out. will post the function when I'm done.
amacleod
11-Jan-2008
[8984]
I want to sync some files on a server. what is the usual method? 
This file will be a rebol script so I thought placing a "version:" 
in the rebol header would be logical. I tried to "load/header" but 
I get the whole script and its no evaluated so I can not just get 
the  version value.
Anton
11-Jan-2008
[8985]
Yes, you must write your own version parsing function which loads 
only a part of the file.
btiffin
12-Jan-2008
[8986]
Alan;  You can try  var: load/header/next   first var will be the 
header as object, second var will be the rest of the script as a 
string.   var/1/version should be your tuple!  (assuming you use 
tuple).  In terms of the evaluation it is deemed "light", values 
but not code.  So   version: 3.2.1 ok,  version: to tuple! [3 2 1] 
 won't be a tuple, var/1/version will be 'to   So Anton is correct.


Another thing to check out the mezzanines (from View)  load-thru 
  read-thru  and the source for exists-thru?  These may have some 
hints for what you want.
Robert
12-Jan-2008
[8987]
Is there an opposite function to SUFFIX? like PREFIX? or so to get 
the filename without extension?
Will
12-Jan-2008
[8988x2]
head clear find/last copy a #"."
to file! head clear find/last copy %prefix.suffix #"."
Ashley
12-Jan-2008
[8990x2]
copy/part f -1 + index? find f "."
to file! first parse f "."
ChristianE
13-Jan-2008
[8992]
If it wasn't for that extra TO-FILE in SUFFIX?, you'd just use COPY/PART:


>> suffix?: func [path [any-string!] "Return the suffix (ext) of 
a filename or url, else NONE."] [if all [path: find/last path %. 
not find path #"/"] [path]]
>> file: %my.test.file.txt
== %my.test.file.txt
>> copy/part file suffix? file
== %my.test.file
Anton
13-Jan-2008
[8993]
AMacleod, I found my version? function in
http://anton.wildit.net.au/rebol/library/dir-utils.r
(after remembering where my website is)
[unknown: 5]
13-Jan-2008
[8994]
I'm just curious if there is a way to make a function think an argument 
was passed to it even though an argument wasn't passed to it.
Henrik
13-Jan-2008
[8995]
a: func [b [word! unset!]] []
[unknown: 5]
13-Jan-2008
[8996]
but could B be used if needed
Henrik
13-Jan-2008
[8997x2]
inside the function?
I haven't tested, but perhaps you can test for 'value?
[unknown: 5]
13-Jan-2008
[8999x3]
yes
that might work Henrick, I'm trying a few things now.
Yep that will work.  Thanks Henrik
Henrik
13-Jan-2008
[9002]
no problem
amacleod
13-Jan-2008
[9003]
Thanks, Anton. I think it is just what I'm looking for.
Anton
13-Jan-2008
[9004]
no worries.
Oldes
14-Jan-2008
[9005x2]
Is there any script which can convert for example -1.8E-5 to -0.000018 
?
formDecimal: func[
	number [decimal!]
	digits [integer!]
	/local negative? p result
][
	if digits <= 0 [return form to-integer 0.5 + number]
	if negative?: number < 0 [number: - number]
	p: power 10 digits
	result: form to-integer number * p + 0.5
	if number < 1 [
		insert/dup result "0" (1 + digits - length? result)
	]
	if negative? [ insert result "-" ]
	head insert skip tail result negate digits #"."
]
Graham
14-Jan-2008
[9007]
should have a native that does this
Gregg
15-Jan-2008
[9008]
There was an old one from Eric Long, that might be in REBOL.org. 
I don't think I ever tackled that with my FORMAT function.
Gabriele
16-Jan-2008
[9009]
i have one i've used for a long time too... also adds ' every three 
digits... i added support for scientific notation recently (because 
form always gives sci notation on Wine)
Henrik
24-Jan-2008
[9010]
how is it again that I can rebind a function to a different context?
Anton
25-Jan-2008
[9011]
>> c1: context [var: "orig" f: func [][print var]]
>> c1/f
orig
>> c2: context [var: "hello"]
>> bind second get in c1 'f c2
== [print var]
>> c1/f
hello
Henrik
25-Jan-2008
[9012x4]
it seems not to work, if the function starts out as global
>> a: does [print b] 
>> c: make object! [b: 4]
>> a

** Script Error: b has no value
** Where: a
** Near: print b
>> bind second :a 'c

== [print b]
>> a
** Script Error: b has no value
** Where: a

** Near: print b
solved with:

bind second :a c
thanks, Anton
[unknown: 5]
25-Jan-2008
[9016]
Can someone explain the reason why bind would work but bind/copy 
wouldn't?
BrianH
25-Jan-2008
[9017x2]
You don't rebind the function, you rebind its code block - not quite 
the same thing. Bind/copy wouldn't work because it creates a copy 
rather than rebinding the original block. You can alter the contents 
of the code block of a (R2) function, but you can't change the function's 
reference to that block to point to another block.
If you can create a new function, you can use bind/copy. It is occasionally 
possible to arrange your algorithm so that it is possible to replace 
a function without worrying about aliased references, but usually 
not.
[unknown: 5]
25-Jan-2008
[9019]
yeah I understand that but why would bind/copy ever fail where bind 
itself worked?
Anton
25-Jan-2008
[9020]
bind/copy goes deep.
[unknown: 5]
25-Jan-2008
[9021x2]
yeah
shouldn't it still work regardless
Anton
25-Jan-2008
[9023]
I think I remember, bind/copy is just a short equivalent to bind 
copy/deep.
[unknown: 5]
25-Jan-2008
[9024]
but if bind works and then you try the same code with bind/copy should 
it cause an error?
Anton
25-Jan-2008
[9025]
Just used when you don't want to modify the bindings of the original.
[unknown: 5]
25-Jan-2008
[9026]
yeah that is the way I understand it also which is why it suprised 
me in my code that bind works but when I simply add bind/copy in 
then it breaks the code.
Anton
25-Jan-2008
[9027x2]
Well, probably no error straight after binding, but if some other 
code rebinds it perhaps causes error later.
It depends on the situation. What is the situation you are in ?
[unknown: 5]
25-Jan-2008
[9029]
yeah that might be it
btiffin
30-Jan-2008
[9030]
What is the deal with mod and modulo?   What should   mod 10 3   
 mod 10 -3    mod -10 3   mod -10 -3   return?  Not what REBOL returns 
... what's the math of it supposed to be.


I accept  1 and 2, but -4 (mod -10 -3) freaks me out.  I don't use 
mod very often (and never with negative divisors or dividends), but 
it came up in a conversation with some student programmers (and I'm 
trying to convince them to give REBOL a try).