World: r3wp

one of the advantages of being only 700kb  ;-)

ok but now when i start the file directly i get ** Syntax Error: 
Script is missing a REBOL header
** Near: do/args script system/script/args

my-func: func [] [
	n: to-integer ask "enter a number"
	if  n < 0  [quit/return 1]
	sum: 0
	i: 0
	while [ i <= n ] [ sum: sum + probe (i * i)  i: i + 1]
	print sum
]

ah yes.   scripts *must* start with rebol's header.

rebol [  ]

this is the body of the file

did you add the first line:

REBOL []

?

REBOL[]
my-func: func [] [
	n: to-integer ask "enter a number"
	if  n < 0  [quit/return 1]
	sum: 0
	i: 0
	while [ i <= n ] [ sum: sum + probe (i * i)  i: i + 1]
	print sum
]

like so?

you can see that Rebol is case insensitive  ;-)

yep

yep.  and don't forget to run the function at the end...

I'd also put a trailing ask ""

REBOL[]
my-func: func [] [
	n: to-integer ask "enter a number: "
	if  n < 0  [quit/return 1]
	sum: 0
	i: 0
	while [ i <= n ] [ sum: sum + probe (i * i)  i: i + 1]
	print sum
]

my-func

ask "press enter to quit"

ok trying that as well,on a side note now the file does not start 
:D

sry my mistake

if you didn't put an ask at the end... just just didn't see it cause 
it closed to quicly.

works fine

yeah THAT i figured out from reading the libraries thanks alot guys 
you are great

if you press escape at any point,  the execution stops and you are 
sent to the console... try it.

cool

now try it with a negative number and the console will quit on its 
own (since I put a return/quit 1)

if you just want the function to return   remove the /quit 1

really nifty

/quit  is a  Refinement   a special function datatype which can be 
used in functions to supply additional parameters or instructions 
to a function.

ok i am beggining to love this language

so everything aside i really got into the basics thank you fo that

refinements is how REBOL gets away without any parens because the 
number of arguments is always known.

no problem... its always fun to have new users.  :-)

what do you mean always known

Be careful......Max is feeding you the red pill.

ex:

my-func [value /optional opt-value] [
	probe value
	if optional [
		probe opt-value
	]
]

my-func 33
my-func/option 22 "tadam"

because you added the refinement, it knows to expect an additional 
argument.

oops... 

my-func: func  [value /optional opt-value] [

thnks guys really gr8 community unfortunately my timezone says:go 
to bed or don`t bother at all" :D so i will leave the pc now but 
i will leave the chat on if i think os something in my sleep

alemar - where are you from?

bulgaria

it`s barely 22:30 but i got a lot to do tommorow

I am from Czech Republic ....

:D

and when its needed, you can force input types:
fixed a few typos... this should work right:


my-func: func [value /optional opt-value [string!] ] [
	probe value
	if optional [
		print length? opt-value
	]
]

my-func 33
my-func/optional 22 "tadam"
my-func/optional 22 44

the name did seem a bit slav... :D

tnks pasin to my little vault..

pastin

thinking of using objects for the first time, using them to capture 
clinical data for patients.
Need to capture data by time; still just a fuzzy idea.

I have read how you can extend an object by simply redefining it 
with new values, but I wonder if there is a way to REMOVE elements 
from an object?
TIA!

In R2, you can do this:

1. get the body of the object as a block
2. find the word you want to remove
3. remove the word and its value coming right after
4. make a new object from the block

ah!  That makes sense!  Thank you Henrik!  It is good to be working 
(learning) REBOL again, knowing that help is so fast to find on AltMe.

I notice you specified R2 - without asking for details, will this 
be different in R3?

In R3 you have more options for manipulating objects a little bit 
like series, without having to re-make the object, although I'm uncertain 
that you can remove elements from objects. But then you also have 
the map! datatype, which is more suitable for very quick adding and 
removing of key/value pairs.

map!
 ??  so much to learn.  Again, thank you!

http://www.rebol.com/r3/docs/datatypes/map.html


I see it has not yet been documented. I seem to remember that it 
was, but I might be wrong.

You won't be able to remove elements from an object even in R3, because 
it would break binding. But you can create a new object without the 
field, or use a map!, just as Henrik says. Note that you can also 
TRIM objects in R3, which will make a new object based on the old 
one with unset fields and fields set to none not included in the 
new object.

>> trim context [a: 1 b: none]
== make object! [
    a: 1
]
>> trim context [a: 1 b: 2 unset 'b]
== make object! [
    a: 1
]

interesting