World: r3wp

My question really is, how do I escape the space character as one 
would in regular expressions?

you need parse/all

correct, and then, how do you place the space in the rule: {} ?

#" " or " " or { }

'space works too

parse/all is really your friend - no unwanted surprises ....

That's it? 'space? That is easy.

sorry , it only exists in R3

Yes, parse/all is great, and this is why I want to include the space 
not as a delimiter but as a character in the rule. As if, sometimes 
I want to find two strings separated by a character.

So #" " should do. I will try it. Thank you.

but you can make your own easly ;-)
space: #" "

>> a: "a b"

== "a b"

>> parse/all a ["a" " " "b"]

== true

My script works, but you know how it goes. Once a question creeps 
in the brain, it needs an answer. Thank you.

I would use #" ", or defined a space rule first: spaces: charset 
" ^-" (eventually include tab)

Thank you all.

some space 
is even better to my mind

some space 
is even better to my mind

>> spam: "[15/May/2010 17:59:56] IP address 190.101.1.10 found in 
DNS blacklist SpamHaus SBL-XBL..."

== {[15/May/2010 17:59:56] IP address 190.101.1.10 found in DNS blacklist 
SpamHaus SBL-XBL...}
>> replace/all spam "]" "" replace/all spam "[" ""

== {15/May/2010 17:59:56 IP address 190.101.1.10 found in DNS blacklist 
SpamHaus SBL-XBL...}
>> blk: parse/all spam " "

== ["15/May/2010" "17:59:56" "IP" "address" "190.101.1.10" "found" 
"in" "DNS" "blacklist" "SpamHaus" "SBL-XBL..."]
>> date: blk/1
== "15/May/2010"
>> time: blk/2
== "17:59:56"
>> ip: blk/5
== "190.101.1.10"

nice ....

trim/with "[]" is better to remove things...

rebol and logs are like bread and butter

yeah ... I used it often ... read/lines is your friend :-)

yep nothing in the world can beat this combination

Structured data like logs, but Rebol shines even when parsing unstructured 
data

Yep, this is my script to dig the IP's inside the log files. I was 
quiet excited to see how natural it was to write this:

digits: charset "0123456789"

ip: [some digits "." some digits "." some digits "." some digits 
]

newList: [] 
existingList: []

files: []
foreach file read %. [
	if find file "security.log" [
		split: parse read file none
		foreach it split [
			parse it [[ip] (append newList it) ] 
		]
	]
]

Then, I said, read only from the last read, and pare the date/time. 
I wanted to parse date AND time at the same time" [15/May/2010 17:59:56] 
But I hit a snag because of the space in between. I don't want date 
and time separater beause rebol can parse the string into a date-time 
easy. The space gave me trouble, and the brackets too.

I would write th ip rule more strictly.
ip: [1 3 digits 3 [#"." 1 3 digits]]

Using the charset did not work. So I did this: parse/all txt [thru 
"[" copy found to "]" ]. And said to myself, time to learn more and 
could not find resources.

g so helpful.

Thanks.

What is the problem in parsing date and time at the same time? I 
somehow don't understand, if the solution does what you need, or 
you need further help?

lines: read/lines file
foreach line lines [ ... ]

Pekr, I'm done. Thanks. Initially I could not figure out how to escape 
the space character.

the funny thing (that confused Pekr) about it is, that you did not 
realize, that there was no need to escape the space character :-)

for Graham : delimeters = delimiters

I should've read the entire core manual before posting. Chapter 15 
addresses this clearly.

Processing text and rules seems so natural to rebol. I think I'm 
going to enjoy this.

Once you get used to PARSE, it's very hard to use other languages. 
:-)

I've uploaded my old Whitespace interpreter that I implemented in 
PARSE to GitHub: http://github.com/hostilefork/whitespacers/raw/master/rebol/whitespace.r

What's interesting about it is the comparison that can be made to 
implementations in other languages.  I've collected implementations 
of whitespace interpreters in several other languages (by other people) 
in that project: http://github.com/hostilefork/whitespacers/

Ok, continuing the discussion from "Performance" group, I'd like 
to ask for some help with parsing rebol format files.

Basically, I'd like to be able to extract a block near the beginning 
or end of a file, while minimizing disk access.

The files to be parsed could be large, so I don't want to load the 
entire contents, but chunks at a time.

So my parse rule should be able to detect when the input has been 
exhausted and ask for another chunk.

(When extracting a block near the end of a file, I'll have to parse 
in reverse, but I'll try to implement that later.)

And why you don't want to use the load/next which was advised?

Using LOAD/NEXT, I still have to use a O(n^2) algorithm. I'd now 
like to do my own parse, which can be O(n).

As far as I know, there is no way to instruct LOAD/NEXT to only read 
chunks from the file as necessary to load the next value.

Which is why, in that algorithm, I had to iteratively: load a chunk, 
append it and try LOAD/NEXT until it succeeded.
Which gives the algorithm O(n^2) performance.

My question for this O(n) parse algorithm is:
What rebol syntax do I need identify?
I suppose all I need is:
 - Comments (lines beginning with semi-colon ; )

 - Strings (single-line "" and multi-line {} ) watching out for escape 
 sequences eg. {^}}
 - Blocks

yes

Have I missed anything ?

just that comment may not be on line beginning so far