World: r4wp

>> import %./cURL-binding.so

** access error: cannot open: %./cURL-binding.so reason: "not found 
or not valid"

any ideas why? i'm on a amazon linux instance...

Have you installed all the libraries required for cURL?

i think so graham - did a yum install curl

and i can curl http://google.comfine

Guess have to ask Kaj then ... I tried this before and worked fine 
for me

thanks graham...hoping kaj will see this...

Here you can find some info:
http://rebol.esperconsultancy.nl/extensions/cURL/

Question about an example from the R3 docs:

str: "abcdef"
end: find str "d"
for s str end 1 [print s]
abcdef
bcdef
cdef
def


find finds the d at position 4, if I replace end with 4, I get the 
same result.
However: type? end says string! and no pointer

If I replace the text in str, end still equals to "def", so it does 
not point
at str any more.
Can someone explane this?

'find returns the string at certain position, just print 'end, and 
you will obtain "def"

your 'for construction looks strange, I am wondering it works :-)

It does, both in R2 as in R3, this is from http://www.rebol.com/r3/docs/guide/code-loops.html#section-3

In Rebol, there is no "pointer" (C like).

string!, binary! are series. Series are groups of elements (character, 
octet) so a word! (like str or end) associated to a serie hold also 
a position on it.

You can mak as many sords you want pointing to the same serie at 
the same or different position.

mak=make  sords=words (sory)

Understanding your cade form the interpreter point o view :

How can I find out that the for loop exchanges end with 4, exept 
for looking it up myself ?

str: "abcdef"

==> Create a string! in memory, put "abcdef" as its content, create 
a word! 'str an make it point to its head.

hmm, I just tried for i 1 str 1, and it screams ... but maybe if 
given the same type, a string for e.g., maybe it takes their index 
value?

>> index? str
== 1
>> index? end
== 4

you should know, that 'end is just a reference to still the same 
str, which can be proven, by inserting new element into str ....

Yes, index? does it! Thanks Pekr

end: find str "d"

==> search for "d" in the "abcdef" series in memory, then create 
a word! 'end that hold the position of "d" in this same serie.

>> insert str "0"
== "abcdef"
>> str
== "0abcdef"
>> end
== "cdef"

so 'str and 'end just hold different position in a unique string!

good point, DideC

Tried that myself, but no change in end, which Rebol version are 
you using?

Then, the 'for loop can work as it's positions in a unique serie!

2.7.8

Kees - beware - rebol series concept needs really carefull aproach 
- it caused me a headache when working with series, till I became 
accustomed to it. And still, sometimes, I use trial and error aproach 
in console ...

Kees - better start with a fresh session, fresh series ....

If I replace the text in str, end still equals to 
def", so it does not point
at str any more."
How do you replace the text in 'str ?

If it's like this:
	str: "new text"

then you have created a new string! in memory and point 'str to this 
new serie. 'str and 'end does not point anymore the same string!

try on one line in console:


>> str: "abcdef" end: find str "d" print end insert str "0" print 
end
def
cdef

Kees: there are 'replace and 'change functions ....

or:

>> str/3: #"1"
== #"1"
>> str
== "0a1cdef"

to change the content of the "abcdef" string! you create in first 
place you have to change it in some way.
Pekr used 'insert to add a character in the begining.
You can change all its content like this:
	insert clear str "new content"
then
	probe end
give
	" content"
So we have acted on the same string in memory.

Yes I see that now

Thank you both!

You may read the series page http://www.rebol.com/docs/core23/rebolcore-6.html

Thanks DideC, I will

Yes, that chapter is kind of ... essential imo :-)

If the two words represent the same string (but different position), 
then this will return true:

>> same? head str head end
== true

The key with series programming in Rebol is always "Is this the same 
serie or a new one ?"
Sometimes you want to act on the same.
sometimes you want to act on another.
FUNDAMENTAL

#[[DIdeC
str: "abcdef"

==> Create a string! in memory, put "abcdef" as its content, create 
a word! 'str an make it point to its head.
]]


- that is not true, in fact. The proper description is as follows:

    str: "abcdef"


is a Rebol source (or a part of it). That source is first processed 
by LOAD. LOAD creates the Rebol value representing "abcdef". Also, 
LOAD does *not* set the 'str value (yet).


Later on, when the DO function evaluates the (already LOAD-ed code), 
it just makes the 'str variable to refer to the string value not 
creating anything at all (this difference is crucial).

Dide, you should make sure you understand this difference.

There is even a possibility to write:

    end: #[string! "abcdef" 4]

I can give you a similar description as above even for this case, 
if you like.

Yes you are right.

Ladislav: "this difference is crucial" Could you please explain why 
this difference is important? Or better why it is important to understand?

I understand there is a big difference, but why it is important to 
know?

Endo, you may know this case:

my-code: [s: "" append s #"x"]

do my-code
do my-code ; == "xx"


my explanation is accurate for this case as well. You can see that 
the string (the "" value following the s: set-word) was created by 
LOAD only once, while append occurred twice expanding the string 
to contain "xx".