World: r3wp

initially: func [[throw] tag [word!] code [block!] /local tags] [
    tags: []
    unless find tags tag [
        insert tail tags tag
        do code
    ]
]

I suppose a catch attribute would be appropriate to add to the function 
too.

Or you could eliminate the tag:
initially: func [[catch throw] code [block!] /local done] [
    done: []
    unless find done code [
        insert tail done code
        do code
    ]
]

Sorry, not insert, insert/only.

It relies on the FIND finding blocks based on whether they are the 
same, not equal. That means that the reference to the code block 
that is passed to INITIALLY can itself be used as a tag.

Final version:
initially: func [[catch throw] code [block!] /local done] [
    done: []
    unless find done code [
        insert/only tail done code
        do code
    ]
]

Rambo 3115 submitted for desire to include the replace-all function.

RobertS; Regarding initial blocks, make sure you check out http://www.fm.tul.cz/~ladislav/rebol/
and in particular http://www.fm.tul.cz/~ladislav/rebol/#section-5.6
  As Ladislav himself puts it, "a comfortable Func replacement".


An lfunc does all the work of localizing words set in a func, allows 
an init block (of which set-words are wrapped in use for static variables) 
 etc...etc...

Version with reset (that catch attribute is unnecessary):
initially: func [[throw] code [block!] /reset /local done] [
    done: []
    either reset [clear done] [
        unless find done code [
            insert/only tail done code
            do code
        ]
    ]
]

Or you could remove the code block parameter on reset, if you prefer 
to get rid of one block instead of them all.

Anyone know why there is a space after the first string?

>> form reduce [ "hello" newline "there" ]
== "hello ^/there"
ie. why isn't it "hello^/there" ?

No matter.

I'm more surprised that there isn't a space after the newline, since 
form throws those in everywhere :)

the string may be trimmed, which could be why there's no space after 
the end.

form reduce is the same as reform, btw.

Might be related to, how PRINT is working, which has a built in reduce. 
This would look weird, if there was a space after the newline:

>> print ["Hello" newline "World!"]
Hello 
World!

And you need those spaces, when doing something like:

>> print ["Hello" "World!"]
Hello World!


So it's because REBOL is clever and do, what you expect. (Mostly.)

The space before the newline is annoying ...

Hello <-extra space
World

I can understand spaces between words ... but at the end of a line??

Anyone object to this ?
reform [ "Hello" "world" newline "Again" ] => {Hello word^/Again}

I bet, it's faster, the way it is. The internal rule is:

Add a space after a non-newline.
Don't add after a newline.

May be annoying, but it's fast and small code.

I doubt that adding a new rule - don't add a space if next character 
is also whitespace will slow a native down much.

Would it break anything to treat whitespace as special?

or just rejoin:

>> form rejoin ["hello" newline "there"]
== "hello^/there"

rejoin evaluates the contents though which I don't want

I'm only using reform here for clarity .. in reality I use 'form

It's a very little annoyance, that you can work around. If REBOL 
were close to perfect, it would make sense to go into such things. 
There are much larger problems or things, that's nott finished with 
R3. (My opinion.)

The reason I note this is that I was inserting an EPS into a block 
of words and then forming it.  This adds an extra space on to the 
image data in the EPS and as the routine in the EPS to read the image 
data is white space sensitive, it dies.  I have to do a replace/all 
{ ^/} {^/} on it before I submit to the printer.

Graham reduce evaluates the contents also.

Rejoin is even built off of reduce.

is there better way how to do this?:
>> trim/all/with form to binary! #"*" "#{}"
== "2A"
or
>> copy/part skip form to binary! #"*" 2 2
== "2A"

maybe:
 skip form to-hex 232 6

>> enbase/base "*" 16
== "2A"

Or  first to binary!  42.0.0  ?

Never mind.  :)

Sorry, just found out that to binary! on tuples moves binary and 
not formed binary.  And wanted to try it.  Not what you want in this 
case.

Greetings,my name is Brian (http://hostilefork.com).   I am new to 
REBOL, and was introduced here by Reichart.  I have a question I 
can't yet figure out.

In REBOL if I do switch 'x [x [print "hello"]]

I get 
hello

If I do switch 'x [ to-lit-word x ["hello"]]

I also get hello

My question is the following: how do I get hello in the following 
situation

switch (What goes here?) ['x [print hello]]

switch to lit-word! 'x ['x [print 'hello]]  should work.  It all 
comes down to knowing when values are evalutated.  


'x  outside a block is evaluated as the literal word x and is seen 
as the word! x   ['x]  inside a block is unevaluated until reduced 
so is in the block as an actual  lit-word!  'x   Clear as mud?   
Same for none.  Outside a block (or anytime evaluated, none is a 
value none of type none!   Inside a block it is simply a word!  that 
hasn't been given a value.  That case got me a few times  if  first 
 [none]   ...   is true, as all word! data tests as true.   if first 
reduce [none] is the false case.  mold/all can be you friend when 
exploring this.

And when I say "given a value", I mean an evaluated value.   words 
in blocks have value, just not a variable substituion "value".   
Oh and I suck at explaining this.  :)

Yes, it comes to evaluation. In the second example, the block isn't 
evaluated, which can be seen with this:

>> switch 'x probe [ to-lit-word x ["hello"]]
[to-lit-word x ["hello"]]
== "hello"

If you try reducing the block, you get an error:

>> switch 'x reduce [ to-lit-word x ["hello"]]
** Script Error: x has no value

What you tried to do was this:

>> switch 'x reduce [ to-lit-word 'x ["hello"]]
== none


You can get it to work AND get the block reduced with this (if that's 
what you want):

>> switch 'x reduce [ 'x ["hello"]]
== "hello"


The thing is, putting a lit-word in a variable, and it's seen as 
a word, when evaluated (I think):

>> a: to lit-word! "x"
== 'x
>> type? a
== word!

I hope, it makes it a little clearer.

note, in your second example, the to-lit-word x is not really evaulated.

I would like to propose an addition for R3

When deguggin successive expressions it is a drag to keep shuffling 
down 
  comment {
until the suspect is reached
Could we not use
	;{
to be the equivalent pf
	comment {
for code which has a REBOL header with a
	needs:
that points to an R3 version?