World: r3wp

yes, my initial reply was a bit hasty too.

Don't know whether this has been discussed / RAMBOed yet, but I think 
a smarter reduce (either a refinement or another word) which could 
handle:

	reduce [now then]

instead of requiring:

	reduce [now 'then]

or

	compose [(now) then]


would make writing dialects a lot easier as unset! is rarely a legitimate 
value within a dialect (i.e. I'd like to reduce blocks before parsing 
and words without a value should just be left as is).

Something like:

reduce2: make function! [
	block [block!]	"Block to reduce"
	/deep		"Reduce nested blocks"
	/local blk

 "Evaluates a block of expressions, skipping words without a value, 
 and returns a block."
] [
	blk: copy []
	foreach word block [
		either block? word [
			either deep [
				insert/only tail blk reduce2/deep word
			] [insert/only tail blk word]
		] [insert tail blk either value? word [do word] [word]]
	]
	blk
]


>> reduce2 [red x now now/date (1 + 1) [red x now now/date (1 + 1)]]

== [255.0.0 x 24-May-2006/13:12:14+10:00 24-May-2006 2 [red x now 
now/date (1 + 1)]]

>> reduce2/deep [red x now now/date (1 + 1) [red x now now/date (1 
+ 1)]]

== [255.0.0 x 24-May-2006/13:12:26+10:00 24-May-2006 2 [255.0.0 x 
24-May-2006/13:12:26+10:00 24-May-2006 2]]


but as a native! and able to handle funcs with args (e.g. reduce2 
[print "hi"]).

Here's a different approach to get the result I'm after:

cast: make function! [
	block [block!] "Block to cast"
	words [block!] "Words to convert into literal words"
	/local blk word
	"Casts nominated words within a block into literal words."
] [
	blk: copy []
	repeat i length? block [

  insert/only tail blk either find words pick block i [to lit-word! 
  pick block i] [pick block i]
	]
	blk
]

>> cast [area red button green 'btn blue] [area button]
== ['area red 'button green 'btn blue]
>> reduce cast [area red button green 'btn blue] [area button]
== [area 255.0.0 button 0.255.0 btn 0.0.255]

>> reduce/only [area red button green 'btn blue] [area button]
== [area 255.0.0 button 0.255.0 'btn 0.0.255]

Does that do what you need?

Doh! I'm an idiot. I even read the help text on reduce ... but failed 
to read the text associated with the words refinement. Thanks for 
that, that is one refinement I'm *never* going to forget now. ;)

Please disregard my previous postings.

Yeah, I get that feeling here a lot too :)

REBOL keeps surprise us again and again! :-)

I was a little surprised that the lit-word didn't turn into a word. 
That could be useful. I'm going to do some experiments to see what 
else reduce/only doesn't do. Should be fun.

Why I am not able to OPEN file which I can READ ?

Example?

'read must 'open a file

Open/read may be the difference

Ladislav yes, that was the problem, thanks

Ashley, but reduce/only doesn't perform according to your  initial 
spec "Evaluates a block of expressions, skipping words without a 
value, and returns a block."
>> reduce/only [now then]
** Script Error: then has no value

Huh? that's not the error I get:
>> reduce/only [now then]

** Script Error: reduce expected words argument of type: block none
** Near: reduce/only [now then]

Ah but maybe that's still your point - not what Ashley asked for.

Docu is wrong. it does not reduce words in the /only block. But it 
also rejects functions. so
>> reduce/only[then][then]
== [then]
but it also rejects functions, here unfortunally:
>> reduce/only[now][]
** Script Error: Invalid argument: now
because of security-reasons (draw-blocks from untrusted code).

but reduce/only doesn't perform according to your  initial spec
 True, on two counts:

1) It doesn't evaluate expressions (even if parenthesized)

2) You have to predetermine what words to ignore (less of an issue 
for dialects)

I still can't see a simple way of doing the following:

>> reduce [b: button red form now/date]
** Script Error: button has no value
** Near: b: button red form now/date
>> reduce/only [b: button red form now/date] [button]
** Script Error: Invalid argument: form
** Near: form now/date
>> reduce/only [b: button red (form now/date)] [button]
== [b: button 255.0.0 (form now/date)]


although at least the last case gets most of the way there. What 
I'd really like is:

>> reduce/ignore [b: button red form now/date]
== [b: button 255.0.0 "25-May-2006"]

I am using my BUILD dialect http://www.fm.tul.cz/~ladislav/rebol/build.r
to do it as follows:

>> build [b: button ins red ins form now/date]
== [b: button 255.0.0 "25-May-2006"]

or, another alternative:


>> build/with [b: button red form now/date] [red: system/words/red 
form: get in system/words 'form]
== [b: button 255.0.0 "25-May-2006"]

Use do/next in the parse rule. (that's the reason I suggested the 
DO command for parse some time ago...)

Not sure I understand, a small example would help. ;)

Or was your comment intended for Ladislav?

Ashley: reduce /only -- Only evaluate words and paths, not functions
So the results you are getting above seems logicalto me.

I understand what reduce/only is doing, it's just not doing 100% 
of what I want! ;)

Ah got it ;-)

I think VID like parser is the way then.

Funny, that's what Anton just said in the RebGUI group. ;)

rest: [1 + 2 button 3 + 4] 
out: copy [] 
while [not tail? rest] [
    either find [button] first rest [
        append out first rest 
        rest: next rest
    ] [
        set [res rest] do/next rest 
        append/only out res
    ]
] 
?? out 
comment "or parse" 
rest: head rest 
out: copy [] 
parse rest [
    any [
        set word ['button] (append out :word) 
        | rest: skip (
            set [res rest] do/next rest 
            append/only out :res
        ) :rest
    ]
]

That trick should help with rebgui too.

Ashley, the idea is that in parse, when you get to something you 
want to evaluate, you set a marker and use do/next. like in volker's 
example. my compile-rules provided  a way to do this automatically 
:)

If you can convince Carl to take that feature please :)

the problem is that it "breaks" the parse logic, because you cannot 
backtrack a do/next (side effects)

Volker/Gabriele: thanks, got it now.

I would left that to the user.

It has its purposes without side-effects. And you can have side-effects 
in the parens too, eg a do/next ;)

Is there any script for ftp upload of large files?

srcp: open/direct/read src
trgp: open/direct/new/write trg
while [not none? buf: copy/part srcp 1000][
	prin "#"
	insert trgp buf
]
insert trgp crlf
close trgp
close srcp

Does that work for FTP ?

yes:-))) the insert trgp crlf is not needed

the trick is, thet there must be the /new switch in the ftp port 
(as at least my ftp server do not support append)

Hm, but now how to make directory thru FTP:(

ah it's easy as well, just using make-dir... I'm reboling so many 
years and still am so suprised how simple it can be:-)

Just be aware that make-dir/deep usually doesn't work with FTP

anton has a fix for that

I found that make-dir/deep doesn't work, so I patched FTP OPEN so 
that it creates deep paths as necessary.

This means you no longer have to worry about creating the directory, 
you only need to WRITE your file.

Though you may want to worry about the set-modes for the automatically 
created folders.

http://home.wilddsl.net.au/anton/rebol/patch/ftp-open-new-patch.r