World: r3wp

amacleod, you might get confused by some small inconsistent in REBOL?

>> {a
{    ^-b}
== "a^/^-b"
>> {a
{    ^-b
{    ^-c}
== {a
^-b
^-c}

Amacleod -- please ignore my effort -- it fails to retain the tabs. 
Sorry!

(My last example was from the console, in case it isn't obvious.)

Geomol, yes the known word just defines the context.

I use two binds because there are two contexts involved - the h/q/1 
context, and the function's context. (Each time you create a function, 
a context is created for its locals.)

do bind [code b] ctx


would not do what we want, because it would only bind the two words 
in the block ('code and 'b) to the context.

What we want is to bind the words *inside* the block that 'code refers 
to.  Bind considers each word inside the block, checking to see if 
they are in the target context. If so, they are rebound to the target 
context.  This step essentially gives the words a useful meaning, 
the meaning that's intended, and the meaning that's defined in the 
target context, not in some other context like the global context.

So BIND selectively "paints" a context over words in a block. BIND 
recurses into sub-blocks to do this, but does not get the value of 
words and recurse into them too, if they are blocks. This is why 
  bind [code] ctx   does not affect the CODE block; it only affects 
the 'code word (and only that instance of the 'code word, not any 
other instances floating around elsewhere in the system, in their 
own blocks.)

What we want is to bind the words *inside* the block that 'code refers 
to.
Ah yes. I get it now.

Would be easier (for me)  to have something like "do/bind-here code", 
where all words in the code are bound in the context where there 
is the "do".

Davide, that is not possible in rebol, because there is no concept 
of "here". That is, there is no "current" context. That's just an 
illusion created by groups of words travelling together in blocks. 
Every word has its own binding. Just because several words in a block 
often have the same binding does not mean that the block knows anything 
of the context. This word-binding is a unique feature of rebol, and 
people used to other languages confuse it for scope, which is less 
flexible.

Why is it, that b is not auto-bound to the function in this example?

>> f: func [b code] [do code]
>> f "hi" [print b]
** Script Error: b has no value


I mean, passing [print b] as an argument to the function, it's just 
a block of words without meaning initially. When handed to f, f takes 
over and will now do it. So f has to find out, what's the meaning 
of the inside of the block. First it finds the word "print", which 
makes sense. Then it find the word "b", and this doesn't makes sense 
to f. Why not?

Why: 
>> {a
{    b
{    c}
== "a^/b^/c"
but: 
 {a
{    ^-b
{    ^-^-c}
== {a
^-b
^-^-c}

I need the entire text sting on one line...

{a^/^-b^/^-^-c}

Yes, it's one of the 'funny' corners of REBOL. Are you sure, you 
really need it on one line? What are you doing with the string?

Geomol, when FUNC is evaluated, a new function is created, along 
with a new "function context", as we say. The words in the function 
body block are then bound to the new function context. There are 
only two words in the block, 'do and 'code.  So those are the only 
words affected.  This binding only happens *once*, at function creation 
time. It does not happen again automatically when the function is 
evaluated for the first time, or any time afterwards. Even if it 
did, it would not affect the block of words referred to by 'code, 
because, as I've said above, BIND does not evaluate words to check 
if they are a block so it can recurse into them. (If it did, that 
would have far reaching consequences.) Not having to rebind words 
each time the function is evaluated keeps it efficient.  If we want 
'foreign' code to be bound to a function's context so it can interact 
with the function's locals, then we have to do it ourselves; functions 
created by FUNC won't do it for us.

I see. If it's more efficient (faster) this way, then it's a good 
thing! :-) I (and others) just have to remember it and act accordingly.

Actually, it would be quite annoying for functions to automatically 
bind code like that. Suppose we had a code block and we wanted to 
send it somewhere, and to get there it must pass through a few functions 
not authored by us. Will the code make it, retaining its meaning 
?  That depends on whether we accidentally used any words that happen 
to be the same name as locals of the functions involved. If we did 
use such a word, then it would be rebound to a function's context 
and change its meaning. That's not typically how functions are supposed 
to be used. Functions are supposed to hide their implementation details 
from the outside world, and have no side-effects.

I used to think, blocks of words didn't have any meaning, until they 
were e.g. evaluated. In one context, the words mean one thing, in 
another something else. When I program, I don't think alot about 
this, I just work with REBOL. Now I some cases, where I might not 
expect the output, I'm getting. Example:

>> a: 1
== 1
>> f: func [a code] [do code]
>> f 2 [print a]
1


Before doing this, I would have guessed, 2 was printed. Funny I haven't 
had such a problem, that I can remember.

Now I *see* cases ...

Remembering some discussion about block pre-evaluation or something. 
So the interior of blocks are being giving meaning, when they are 
born. And you can't put anything in a block:

>> blk: [a 7-]
** Syntax Error: Invalid date -- 7-

I'm using tretbase to store formatted text but tretbase strips carriage 
returns. I've removed the trim/lines function from tretbase but teh 
retrieve functions and search functions etc. expect the data to be 
on one line. Carriage returns can be in the data file as long as 
they are on one line.

Maybe newlines are not stored as one character, but two? Like:

>> str: {^^/}
== "^^/"
>> length? str
== 2

Geomol, you're right, actually, the real meaning of a word is only 
ever actualised when it is evaluated. But you can think of a word's 
binding as its potential meaning. (Above, I wrote as if binding and 
meaning are the same, whereas they are not quite; they are close, 
but binding is one step back from meaning.)

Alan, have you tried this ('s being your string):

	replace/all s "^/" "^^/"

s: {a
{    ^-b
{    ^-^-c}
== {a
^-b
^-^-c}
replace/all s "^/" "^^/"
== {a^^/^-b^^/^-^-c}
>> print s
a^/ b^/     c
Not what I want.

s2: copy s parse/all s2 [some [p: "^/" (change/part p "^^/" 1) skip 
| "^-" (change/part p "^^-" 1) skip | skip]]

Because of tabs? Just do the same replace for them.

THat was my next strp. I thought I was missing some simple conversion.

That's simpler to write, but two passes. The parse I show above is 
more complex to write, but one pass.

s2: copy a parse/all s2 [some [p: "^/" (change/part p "^^/" 1) skip 
| "^-" (chang
e/part p "^^-" 1) skip | skip]]
== true
>> s2
== {a^^/^^-b^^/^^-c}
>> print s2
a^/^-b^/^-c


Anton, It looks like what I want but if aI print it the newlines 
are not reconized???

But if I do it manually: 
>> z: {a^/^-b^/^-^-c}
== {a
^-b
^-^-c}
>> probe z
{a
^-b
^-^-c}
== {a
^-b
^-^-c}

I do not get it. Are there hidden characters?

By adding the secon ^, it escapes the ^ that marks the newline, so 
it is no longer a newline. When you write the string out, then it 
will write out as "a^/^-b^/^-c" which will convert to newlines again 
when loaded. If you're writing out and loading strings, you may have 
to convert the data back yourself when you load it, because REBOL 
won't parse into it to do so. e.g., if you mold an object spec to 
be on a single line like that, REBOL will convert them on load, but 
if you just read a file as a string, it won't.

The confusing thing is, rebol molds short strings and longer strings 
differently. In short strings, the newlines are molded as ^^/ , but 
in longer strings (like yours above) the newlines are "evaluated" 
(moving the cursor to next line).

Check it out:
>> "a^/b"
== "a^/b"
>> "a^/^-b"
== "a^/^-b"
>> "a^/^-b^/"
== "a^/^-b^/"
>> "a^/^-b^/^-^-c"
== {a
^-b
^-^-c}

boom!  That last line is long enough that the newlines are "evaluated".

(It's more complicated than just string length, actually. Exact algorithm 
unknown.)

Greg, I tried wrote it out ot a file and loaded it but it still does 
not print properly

Is there a work around?

amacleod, I think Greg and mine solution both work. They produce 
a string molded so that the two control characters (newline and tab) 
are escaped. You just need to ... ahh... here's where I was going 
to say "just LOAD it." but I get an error message.

>> load "^^/"
** Syntax Error: Invalid path -- ^/
** Near: (line 1) ^/

So maybe do this instead:

	s: "^/"  ; <-- input string

 s: "^^/"  ; <--- specially "molded" string as produced by PARSE or 
 REPLACE above.
	load rejoin ["{" s "}"]  ; <-- specially "loaded" string

the result of which should be the same as the input.

The longer example:

>> s: "a^/^-b^/^-^-c"
== {a
^-b
^-^-c}


>> s2: copy s parse/all s2 [some [p: "^/" (change/part p "^^/" 1) 
skip | "^-" (change/part p "^^-" 1) skip | skip]]
== true

>> s3: load rejoin ["{" s "}"]
== {a
^-b
^-^-c}

>> s = s3
== true

Did you mean: 
s3: load rejoin ["{" s2"}"]  ?
with s2 in the rejoin and not s ?

That seems to work and produce what I'm tring to get...

A little awkward but only two lines for what I want...

Thanks again,  Anton.


I can use this in the short time but I may need to just use SQLite 
or my own solution for storage as Paul is no longer developing Tretbase...

amacleod, can you use NicomDB?
http://www.fys.ku.dk/~niclasen/nicomdb/index.html


NicomDB is the result of an education, I took some years ago. More 
info:
http://www.fys.ku.dk/~niclasen/nicomdb/thesis.pdf

There's also a group about it here in the REBOL3 world. See group 
!NicomDB

amacleod, ah yes, small typo there.

On 'bind, I use 'with to make some bind situations more readable:

	other-context: context [
		print: [statement][probe head reverse copy statement]
	]

	with other-context [print "Text"]

with: func [object [any-word! object! port!] block [any-block!] /only][
	block: bind block object
	either only [block] :block
]

I was looking into sqlite but reluctantly...

Idid a quick glance through your paper and it had a lot of good iseas 
that might fit my needs. I'm going to play around with it.
Are you still developing it?

iseas = ideas

amacleod, I use NicomDB myself in different projects and is developing 
it further, when needs arise.