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World: r3wp

[Core] Discuss core issues

Ladislav
23-Nov-2006
[6349x2]
unfortunately the evaluation looks complicated this way
(but the most reliable)
Anton
23-Nov-2006
[6351]
Ladislav, looks like pairs are treated differently. (not a series, 
even though they really should be ?)
Ladislav
23-Nov-2006
[6352x2]
right, pairs differ from series (are not mutable)
(according to the definition used in http://www.fm.tul.cz/~ladislav/rebol/identity.html
article)
Ladislav
24-Nov-2006
[6354x2]
Path evaluation order once again: it looks to me, that the algorithm 
working as follows:

a: 1x2 a/(a: 3x4 1): (a: 5x6 7)
a ; == 7x2


is more than two times faster than the "more natural" one yielding 
a == 7x6. The difference lies in the fact, that the latter algorithm 
needs to rebuild the path before applying it, while the former one 
can "evaluate on the fly", without rebuilding.
Moreover, the a == 7x2 result is compatible with the way how functions 
are evalutated:

f: func [x] ["first"]
g: func [x] ["second"]
h: :f
h (h: :g 1) ; == "first"
[unknown: 10]
24-Nov-2006
[6356x4]
apparently i lost it completly...;-) 


I have to following issue: I want A to be a block and B thave the 
initial values of A, but B may not change when A changes!

so i tried it all , but it always turns out that b changes with a 
i.e.

a: [ [ 987987 ] [ kljhljkh] ]
b: []
b: a
a/1/1: 'blabla  
then b changes too... ;-) 


Oke..i know this, but how do I apply a to b without b changing to 
'a everytime I change a
I need to be able to compare A with B after A changed x times... 
so B must be a block..when using 'equal? B A
I tried 'append 'insert 'foreach but it keeps changing in B too when 
changing A.. That bring me too an issue in rebol, How can I check 
if a Type is a relative of a different Type? like 'copy does..
Im unable to see if B is a copy of A, i can only check if the Type 
is the same but thats useless I cant check if B is a Relative of 
A...
Ladislav
24-Nov-2006
[6360]
Rebolinth:  you can use b: copy/deep a
[unknown: 10]
24-Nov-2006
[6361x2]
;-) Thats something I never ued befor, I always thought that was 
for the use of nested blocks... Thanks !
Mmmmmm "/deep - Also copies series values within the block."  I cant 
say thats a realy clear eplenation ;-) never the less it works...
Anton
24-Nov-2006
[6363]
It is the most precise explanation.
Gregg
24-Nov-2006
[6364]
Icarii, you can probably use bitsets for what you want. I did some 
bitset math stuff a while back, so Maarten could do 160-bit checksums 
(IIRC).
Izkata
24-Nov-2006
[6365]
How about "Recursively copies series! values within the block." ?
Anton
25-Nov-2006
[6366]
That would be the most precise explanation.
Ladislav
25-Nov-2006
[6367x2]
unfortunately, it doesn't copy all series:
>> a: ["aa"]
== ["aa"]
>> b: copy/deep a
== ["aa"]
>> same? first a first b
== false
ah, sorry, actually, it did, in this case
[unknown: 10]
25-Nov-2006
[6369]
yes its strange actualy to find this function under copy... I would 
expect a name like copy/static or someting..but whats in the name 
;-)
Gabriele
25-Nov-2006
[6370]
rebolinth, well, copy copies. copy/deep copies deeply. /static makes 
me think of the opposite (what does copy/static mean???)
Joe
25-Nov-2006
[6371x2]
hi, I want to call a rebol script in a separate process and pass 
parameters e.g.  launch {c:\script.r param} but does not set  system/script/args
what am i doing wrong ?
Geomol
25-Nov-2006
[6373]
Ladislav, if a: 1x2 a/(a: 3x4 1): (a: 5x6 7) resulting in 7x2 is 
more than 2 times faster than the post-check method resulting in 
7x6, then that is a very good argument to have it that way. Anyway 
your example is something, that should be avoided (if you're a good 
developer, I guess), so speed is better than a "more natural" result. 
That's my view.
Ladislav
25-Nov-2006
[6374]
yes, but the crash can (and should) be eliminated
Rebolek
25-Nov-2006
[6375x2]
if it results in 7x2, does it mean that 'a in paren! is local?
(half-jokingly)
Ladislav
25-Nov-2006
[6377]
I think, that it really needs an explanation.

* The 7x2 evaluation can work as follows: 

1) the interpreter first sets its Path-start variable to 1x2 and 
its Path-variable to 'a

2) the evaluation of the paren changes the A variable, but that does 
not influence the interpreter Path-start variable, so the path will 
be evaluated as Path-start/1:

3) the argument is evaluated, which changes the A variable again, 
but not the Path-start. The argument value is 7
4) Path-start/1: 7 is evaluated, which yields Path-start = 7x2

5) The variable A is set to the new value of the Path-start variable


The same algorithm can be used for longer paths too and we do not 
have to remember the complete path - it always suffices to remember 
"where we are".


The 7x6 evaluation cannot work like that, since we never know "where 
we are" - the Path start can change anytime, so we cannot "traverse" 
the path when evaluating parens. We need to "rebuild the path" evaluating 
all parens and remembering all intermediate results. Only when done 
and when the argument is evaluated, we can start to traverse the 
rebuilt path knowing the Path start.
Anton
25-Nov-2006
[6378x2]
Joe, I can't get it to work either. It looks like LAUNCH always just 
converts its VALUE argument to a file and then tries to do it.
Anyone else ? Is this a RAMBOable offence ?
Maxim
25-Nov-2006
[6380]
iskata: I  agree, the word "recursive" makes it more explicit or 
obvious.
Anton
25-Nov-2006
[6381]
I don't think we're about to change the spelling of COPY/DEEP.  "deep" 
is pretty good.
Maxim
25-Nov-2006
[6382x2]
yess I meant the string doc.
if the string docs emphasizes the deep word, right now its not as 
obvious what deep implies.
Anton
25-Nov-2006
[6384]
Oh ok.
Maxim
25-Nov-2006
[6385x2]
how can rebol be made to understand UNC filenames... currently, I 
can't seem to use %//host/  to list shares.  :-(
rebol replaces %// as the root of curent dir... such that %//host/ 
 becomes %/C/host/   for example  :-(
Anton
25-Nov-2006
[6387]
%/host/  ?
Maxim
25-Nov-2006
[6388x2]
nope
%/host/shared/  works...  but  I want to list those shares?  just 
as listing %/ does for local drives
Izkata
25-Nov-2006
[6390]
what happens if you change-dir to %/host/shared/  then change-dir 
to %..  ?
Jerry
27-Nov-2006
[6391]
I was processing a Chinese text file using REBOL. The text file was 
in the Big5 Encoding, which is the de facto encoding we use in Taiwan. 
A Big5 character needs two bytes, so I used strings whose length 
is 2 to present Big5 characters. 


Something weird happened. After a while, I realized that REBOL treated 
two different characters as they were the same character.


Chinese-char1: to-string #{A4 68} ; Big5 Char for "Educated Person"
Chinese-char2: to-string #{A4 48} ; Big5 Char for "Human"

if Chinese-char1 = Chinese-char2 [
    print "This cannot not be happening..."
]
How would I fix my REBOL scrip? Thank you.
sqlab
27-Nov-2006
[6392]
>> strict-equal? probe to-string join #{a4} #{68} probe to-string 
join #{a4} #{48}
¤h
¤H
== false
Jerry
27-Nov-2006
[6393]
Sqlab, thank you.
Gabriele
27-Nov-2006
[6394]
= is case insensitive, but that only works with latin1. you should 
use binary!, not string!, to avoid any problems.
Jerry
27-Nov-2006
[6395]
Is there any way that I could detect whether the Num Lock or the 
Caps Lock is on?
PeterWood
27-Nov-2006
[6396x2]
Not in Core ;-) and I from using Gabriele's keycode onle-line displayer 


view layout [box feel [engage: func [f a e] [switch a [up [focus 
f] key [print mold e/key]]]]]


It looks as though Rebol doesn't provide an event when Caps Lock 
is pressed or released.
I read here : http://www.rebol.org/cgi-bin/cgiwrap/rebol/ml-topic-index.r?i=k
Cyphre
28-Nov-2006
[6398]
It is possible to get keycodes(at least under Windows) even in Rebol/Core: