While ... break

[John]

People hi,
I really need some help.

Can you give me a small example of a while loop using a break
I'm trying this:

Code:

num: [20 30 40 50 60 70 80]

while [not tail? num] [
  print first num
  num: next num
  if num = 60 [break]
]

..but it does not break at 60, the loops prints all values
please help me, where is the error
i want to use while, not for.. or other loop

thank you !

[bouba]

be careful, num is a series!

so it is not

Code:

if num = 60 [break]

but

Code:

if 60 = first num [break]

you could have also written :

Code:

foreach val num [
   print val
   if val = 60 [break]
]

which I find simpler. ;)

[John]

thank you very much    

[CarlRead]

An alternative to...

Code:

if 60 = first num [break]

is...

Code:

if num/1 = 60 [break]

[John]

Thanks Carl, i got it now.


Also i have a problem, i'm trying to run this script taken form Rebol's web site 'How to' section

Code:

view/new layout [

   the-box: box "A Box" forest feel [
       engage: func [face action event] [
           print [action event/key]
       ]
   ]
]
focus the-box
do-events

It says that 'When you type on the keyboard you will see a stream such as:

key a
key b
key c
key d

It's not working on me, every time i run the script, the console crashes !!
Any suggestions ?

I'm using REBOL/View 1.3
Thanks again people.

[Gabriele]

That snippet works fine here.

[John]

I don't know why it's not working on me.

One more question.
I'm having a bit of touble with remove and insert, i'm confused.

In a string like this:

str: "Reboloton"

how to use remove function to remove 't' only and make a new str string: "Reboloon"

And same to insert, how to insert one more 't' and make the string "Rebolotton"

What's the fastest way, can you give me an example?

Thanks again friends.

:rolleyes:  

[Guest]

ok, i found it i used remove/part at str x x



sorry for the silly questions i'm newbie to rebol

[CarlRead]

It says that 'When you type on the keyboard you will see a stream such as:

key a
key b
key c
key d

It's not working on me, every time i run the script, the console crashes !!
Any suggestions ?

I'm using REBOL/View 1.3
Thanks again people.

It works for me too.  What OS are you running REBOL on?

[John]

Windows XP without any SP
Rebol system version 1.3.1.3.1 (without install)

Every time i run the script it opens a window 'A Box'
But i cant close it, and i cant type anything to console even if i press 'esc'

[Sunanda]

John -- have your tried clicking the "a box" -- that's what starts the demo.

After that, you should be able to press keys (etc) and see the result in the REBOL console window.

You can close the window by hitting ESCape in the REBOL console window and then:
 unview/all

[John]

Sunanda thanks for your answer. No i cant find a solution, console halts..

This is 2 small scripts i made.
Nothing special, i will rewrite them when i learn Rebol  :lol:
The first gives 10 unique random numbers (1 - 10)

Code:

;create unique random numbers
numbers: func [] [
num: copy [1 2 3 4 5 6 7 8 9 10]
temp: copy []

loop 10 [
 r: random (length? num)
 v: pick num r
 append temp v
 r: r - 1
 num: skip num r
 remove num
 num: head num
]
print temp
]

copy-paste and type 'numbers'

>> numbers
5 8 4 7 3 2 1 6 10 9



The second is a string permutation function
It finds all letters combinations from a string

Code:

;string permutation
substr: func [string start length][
       copy/part at string start length
   ]

perm: func [string1 string2] [
either (length? string2) = 1 [
  print join string1 string2
  ] [
    for i 1 (length? string2) 1 [
    string2_first_character: pick string2 1
    string3: join string1 string2_first_character
    string4: substr string2 2 (length? string2)
    perm string3 string4

    string2_first_character: pick string2 1
    remove string2
    append string2 string2_first_character
  ]
]
]

Type perm "" "REBOL"

>> perm "" "REBOL"

REBOL
REBLO
REOLB
REOBL
RELBO
RELOB
RBOLE
...




Also i have a question, i realy need your help people
 I make an object with the name of box
 It has a 'state' variable.

Code:

box: make object! [
 state: none
 ]

Now this simple loop below prints ob1 ob2 ob3 ob4 ob5 ..

Code:

repeat x 10 [
str: copy "ob"
append str x
print str
]

My question is how can i make a new box clone with the name of str value 'obx'
And then i can check its value, like this 'print ob4/state'
My English are poor, hope you understand

[Gabriele]

Did you try:

Code:

>> random [1 2 3 4 5 6 7 8 9 10]
== [5 8 6 2 7 1 3 4 10 9]

?

[John]

WOW  :lol:
thank you Gabriele, no i did not try that !