AltME groups: search

Ah ok, then you need to convert the word to a series, for example 
a string, and check on last letter:


parse [some word! other* stuff'] [some [set word word! (print last 
form word)]]

Think of the end of a series as an internal marker, which the user 
shouldn't see as an element in the series, if you ask me.

I think, the docs match pretty well.
thru	advance input thru a value or datatype


You're right, taking this strictly, we should be able to advance 
thru the end. But this doesn't make much sense, so my guess is, most 
people wouldn't take this strictly, when talking the end of a series.

Argh, I was confused by sentences like
Where do you think the cursor is after matching the [end] rule?
:-)
Old def. of thru: advance input thru a value or datatype

New def. of thru: scan forward in input for matching rules, advance 
input to tail of the match


Then it can be argued, the tail of end (of a series) is still the 
end. Or it can be argued, that thru always advance some way further 
(as in all cases except at end). I understand, why [thru end] not 
failing is confusing.

(And stop saying, I should read the doc. I have read it ... in full 
this time.) ;-)

Geomol: "Are there a set of PARSE tests somewhere, that I could test 
my version against?" - there are the core tests at

https://github.com/rebolsource/rebol-test


, that contain a couple of PARSE tests in the functions/series/parse.r 
section. It would be nice if you added some tests.

It seems like an error that is improperly not triggered. SET is supposed 
to set to a single value, not a series of values - an embedded block 
is a single value.

Endo: in your first attempt, your second rule in SOME block is not 
making the input advance when the end of the string is reached because 
(remove "") == "", so it enters an infinite loop. A simple fix could 
be:


t: "abc56xyz" parse/all t [any [digit (prin "d") | x: skip (prin 
"." remove x) :x]]


(remember to correctly reset the input cursor when modifying the 
parsed series) 


As others have suggested, they are more optimal ways to achieve this 
trimming.

Doc: Thank you. I tried to do that way (advancing the series position) 
but couldn't. I may add some more things so I wish to do it by parse 
instead of other ways. And want to learn parse more :)
Thanks for all!

REBOL's installer hasn't worked at all since the 2.7 series, and 
it never worked correctly before that, though the 1.3 series improved 
directory usage. Fixing the installer is on the list for the next 
version.

By next version, I mean next version in the 2.7 series.

It hasn't worked at all for the 2.7 series, and worked incorrectly 
before then.

2.7.7 release

Call
dockimbel:

About CALL console window issue, the CreateProcess( ) win32 call 
has flags to hide the window. There just need to be set.

In the STARTUPINFO used by CreateProcess( ), just set in dwFlags, 
the STARTF_USESHOWWINDOW flag and set wShowWindow to SW_HIDE.

maybe add a new refinement and let the users decide when they want 
to see the console window ?
or maybe just /show

Paul:
Run is not enabled

Graham

Is anyone concerned that shell windows opened in Encap do not contain 
the correct window title?
Rambo #3660 ( reported march 2005 )

Brian

For me, the big question is what kind of release we will be doing:

- 2.7.7: Patching glaring bugs in a few natives, VID fixes, and continuing 
the backports and mezzanine fixes.

- 2.8.0: Backporting some of the R3 native changes (function, not 
infrastructre), and the above.

I think that the decision a long time ago was to focus on R3 as a 
priority, and just patch up R2 as necessary.

At the very least, I would want a 2.7.7 to have a version that fixes 
post-2.7.6 mezzanine bugs, and 2.7 series regressions vs. 2.6.3.

Henrik
We also need to implement BrianH's new window resize scheme.

Ashley,Anton, Brian, etc ... VID fixes

Graham
Fixes to prot-http to support put etc.

BrianH

SQL_FLOAT and SQL_REAL are converted the same way, just with different 
sizes. And yet SQL_REAL works and SQL_FLOAT doesn't, at least with 
SQL Native Client (an ODBC 3.5 driver). Perhaps that difference can 
point you in the right direction.

Henrik
view/new make face []
a: open/binary/direct/no-wait tcp://:9000
forever [wait reduce [ a 0.001]]


This produces a 16 byte leak when started. And when I move the window 
and click in it, I get a lot of 64 byte leaks.

Graham, thanks for copying over those priorities from R2-Beta to 
here. About how those choices were made and phrased:


The R2-Beta world was used when we still thought of REBOL being updated 
more rarely, in larger increments. This is no longer the case, we 
are adopting the rapid release model, though more regulary than the 
R3 alphas. We need to shift our thinking accordingly.


Rapid release means that each individual R2 release doesn't have 
to include fixes for every outstanding bug. We can and will triage 
and prioritize, and your favorite bug may be moved to the next release. 
Which won't be a problem because that's coming next month, or the 
month after. Minor point releases will not be a major deal from now 
on, they will be monthly occurances.


The overall plan for the R2 2.7.x series is to fix what we can in 
R2 in a way that doesn't break things. This won't be a ground-up 
rewrite, as we are doing one of those already. No major model changes, 
just tweaks. There is a lot we can tweak though, including natives. 
We are trying to avoid disruptive changes that affect scripts at 
runtime, except in cases where things just didn't work before. Almost 
all code that works on 2.7.6 should continue to work - that is our 
goal. Don't expect broken code to stay broken though :)


The 2.7.7 release will not be ambitious, we just don't have the time. 
The priorities are business model changes and low-hanging fruit. 
The one piece of major breakage from the 2.7.x series that needs 
fixing in this release is the installer. If you have other priority 
fixes that can't wait til next month, and you are willing to do the 
work in this week, please speak up.

It's been broken for so long, I no longer have the computer where 
I originally wrote it back in 2000 and posted it to the mailing list. 
It's still in my head though, so I'll collect it by Tuesday evening 
and start working. In brief:

- I don't know about installation on platforms other than Windows. 
Someone else will have to chime in here. Too ambitious for 2.7.7.

- Windows 2000+ support is still broken. Multi-user support is broken 
(same thing, really).

- Folder usage was mostly fixed in 2.6.3, but the registry is still 
misused. Registry migration will be needed.

- Non-admin installation should be possible, including user-specific 
file associations.

- Installation was broken altogether in the 2.7.x series - it doesn't 
work at all, not even to 2.6.3 levels.

- No-install usage of View needs better support. This means UI support 
too, if need be. VIew should be able to be a portable app.

Keep in mind that portable app usage of directories is completely 
different than installed usage, and needs to be.

2.7.7 release

Call
dockimbel:

About CALL console window issue, the CreateProcess( ) win32 call 
has flags to hide the window. There just need to be set.

In the STARTUPINFO used by CreateProcess( ), just set in dwFlags, 
the STARTF_USESHOWWINDOW flag and set wShowWindow to SW_HIDE.

maybe add a new refinement and let the users decide when they want 
to see the console window ?
or maybe just /show

Paul:
Run is not enabled

Graham

Is anyone concerned that shell windows opened in Encap do not contain 
the correct window title?
Rambo #3660 ( reported march 2005 )

Brian

For me, the big question is what kind of release we will be doing:

- 2.7.7: Patching glaring bugs in a few natives, VID fixes, and continuing 
the backports and mezzanine fixes.

- 2.8.0: Backporting some of the R3 native changes (function, not 
infrastructre), and the above.

I think that the decision a long time ago was to focus on R3 as a 
priority, and just patch up R2 as necessary.

At the very least, I would want a 2.7.7 to have a version that fixes 
post-2.7.6 mezzanine bugs, and 2.7 series regressions vs. 2.6.3.

Henrik
We also need to implement BrianH's new window resize scheme.

Ashley,Anton, Brian, etc ... VID fixes

Graham
Fixes to prot-http to support put etc.

BrianH

SQL_FLOAT and SQL_REAL are converted the same way, just with different 
sizes. And yet SQL_REAL works and SQL_FLOAT doesn't, at least with 
SQL Native Client (an ODBC 3.5 driver). Perhaps that difference can 
point you in the right direction.

Henrik
view/new make face []
a: open/binary/direct/no-wait tcp://:9000
forever [wait reduce [ a 0.001]]


This produces a 16 byte leak when started. And when I move the window 
and click in it, I get a lot of 64 byte leaks.

well now.... I just had a crash in 2.7.6. Thought that would be a 
little on-topic:

---------------------------
REBOL Error
---------------------------
REBOL Internal Error: Invalid series width 1 was 16 (type 39)

Program terminated abnormally.
This should never happen.
Contact www.REBOL.com with details.
---------------------------
OK   
---------------------------

Posted mezzanine changes for 2.7.8, ported from R2/Forward 2.100.80.0:

- Added COLLECT-WORDS, RESOLVE, SINGLE?, IMMEDIATE!, INTERNAL!, INVALID-UTF?,
  CD, MORE, and the convenience words LS, PWD, RM and MKDIR.

- Removed buggy binary! support from ASCII? and LATIN1?, as done 
in 2.100.60.


See mezz-control.r #6763, mezz-file.r #6776, mezz-series.r #6772, 
mezz-string.r

#6773 and mezz-reflect.r #6771 for the relevant changes. Details 
in R3's docs.


Note: The APPEND and REMOLD rewrites are too awkward to incorporate 
without a

native APPLY function. UNBIND hasn't been written yet (hoping for 
a native).

I would guess 2.5.6, the last version before the 2.6 series. Other 
platforms were dropped after 2.5.0 (like WinCE).

We switch between R2 and R3 work. The last week has been focused 
on R3. A week-or-so ago I made a few tweaks to R2/Forward for 2.7.8, 
including a backported fix from R3, and Carl put together a plan 
and implemented a lot of his portion of the plan. I expect that soon 
after the R3 a98 release, we'll have a R2 2.7.8 release. And 2.7.8 
looks like it will be the first really stable release in the whole 
2.7.x series, something to really look forward to.

If I want to set something to the index of a series, or something 
else if it's not there I have to do this

b: either a: find series var [
	index? a
][ 	default ]

when I'd rather do

 b: any [ index? find series var default ]

So how about letting index? also take none as an argument ?

b: any [ attempt [ index? find series var ] default ]

yep, no need for additional var.

all [b: find series var b: index? b]

indeed, I just meant:

b: either b: find series var [index? b] [default]

index?: func [  [ series! | none! ]
][
	either series [ index? series ][
		none
	]
]

would likely cause a stqack overflow

use [idx?] [
idx?: :index?
index?: func [series [ series! | none! ]] [
	either series [ idx? series ][none]
]
]

I never liked that Carl wrapped all pointer data as SERIES... they 
share very little in fact.


I added quite a few MACROS in my hostkit to make working with a few 
of the types more xplicit in code...  I also wished Carl stored the 
type right in the RXA_ARG ... which is why I did a superset of it 
which has the type value at the end...  then I can just look it up 
instead of passing it as an argument within my own code all the time.

I don't see it as a problem when I write:
    RXA_SERIES(frm, 1) = destSer;
    RXA_TYPE(frm, 1)   = RXT_BINARY;
    RXA_INDEX(frm, 1)  = 0;

At least it's clear in the source, what you can expect. Or what you 
want to propose. It's Maxim's wish:)

Oldes, to get the length of the series use:
RL_SERIES(ser, RXI_SER_TAIL) - RXA_INDEX(frm, 1)

Well, it actually is part of the _argument_, but not of the REBSER 
"series" (which is really the series data).

I.e. if you have an RXIARG of of a series type (RXT_BINARY, RXT_STRING, 
etc), this arg also holds the index.

And a pointer to the series data.

I'm fighting with some "undefined references"

(.text+0x867): undefined reference to `RXARG_SERIES'

Search thru all your source files for RXARG_SERIES and replace it 
with RXA_SERIES

OMG... this is a good example of seeing RXARG_SERIES and understanding 
RXA_SERIES... I though I did this already.

But RXARG (the old one) was a shortcut to access the .series union 
member. The new RXA_SERIES one needs a frame pointer and a number. 
Which I don't need. So, the new approach is to access the union members 
directly?

Is there any other way how to get series index than from RXA_INDEX 
macro?  http://issue.cc/r3/1858

The workaround/solution is simple: don't pass REBSERs to function, 
but use the RXIARG instead and then access the index via .index and 
the REBSER via .series.

I guess RXA_SERIES is simply too tempting :)

The index is simply not part of a series at the implementation level

What appears to be a series with an index in REBOL is actually a 
reference with an index. That's exactly what an RXIARG is. What the 
hostkit level calls a REBSER is the actual series, not a reference, 
so that doesn't have an index

I personally think of the RXIARG (which is a neutered REBOL "value") 
as "the series", and of the REBSER as a subordniate helper structure 
(holding width/size/left and data).

The index is part of the reference for series, not part of the series 
itself.

cbi->obj is of type REBSER* so this suggest to pass in a series. 
A string with the name of the context?


Brian, how does a  "reference to the context containing the function" 
look for this:

rebol []

myfunct: does []

What do I pass to the extension here?

// call R3 callback
	RXA_COUNT(cbi) 		= 1;

/*
	RXA_TYPE(cbi, 1) 	= RXT_INTEGER;
	RXA_INT64(cbi, 1) = 123;
*/

	RXA_TYPE(cbi, 1) = RXT_STRING;
	RXA_SERIES(cbi,1) = RL_Make_String(message);;
	RXA_INDEX(cbi,1) = 0;

	int cb_error = RL_CALLBACK(cbi);

You could try to have the progress callback in the cURL binding pass 
a series. cURL is singlethreaded, so this would establish whether 
it's a threading problem or an R3 memory management/callback problem

all path access is slow...but I woudn't have thought that using a 
series function and multiplying both values in the pair would be 
twice as fast!

Onetom, that error has been reported already and fixed in R2/Forward, 
but it hasn't made it into R2 yet. Here is the revised MAP-EACH:

map-each: func [

 "Evaluates a block for each value(s) in a series and returns them 
 as a block."
	[throw catch]

 'word [word! block!] "Word or block of words to set each time (local)"
	data [block!] "The series to traverse"
	body [block!] "Block to evaluate each time"
	/into "Collect into a given series, rather than a new block"

 output [any-block! any-string!] "The series to output to" ; Not image!
	/local init len x
][
	; Shortcut return for empty data
	either empty? data [any [output make block! 0]] [
		; BIND/copy word and body
		word: either block? word [
			if empty? word [throw make error! [script invalid-arg []]]

   copy/deep word  ; /deep because word is rebound before errors checked
		] [reduce [word]]
		word: use word reduce [word]
		body: bind/copy body first word
		; Build init code
		init: none
		parse word [any [word! | x: set-word! (
			unless init [init: make block! 4]
			; Add [x: at data index] to init, and remove from word
			insert insert insert tail init first x [at data] index? x
			remove x
		) :x | x: skip (

   throw make error! reduce ['script 'expect-set [word! set-word!] type? 
   first x]
		)]]
		len: length? word ; Can be zero now (for advanced code tricks)
		; Create the output series if not specified
		unless into [output: make block! divide length? data max 1 len]
		; Process the data (which is not empty at this point)

  until [ ; Note: output: insert/only output needed for list! output
			set word data  do init

   unless unset? set/any 'x do body [output: insert/only output :x]
			tail? data: skip data len
		]
		; Return the output and clean up memory references
		also either into [output] [head output] (
			set [word data body output init x] none
		)
	]
]

The revised mezz-series.r (relative to the 2.7.8 SDK source) is in 
R3 chat #8008 - that's the number of the particular version, which 
you can see by going to #41 (R2/Mezzanines) and doing a LF command.

FIRST, SECOND and THIRD can be used on functions like:

>> first :repend
== [series value /only]


SECOND and THIRD returns the function body and spec. FIRST returns 
a stripped spec, just the arguments and refinements. I notice, it's 
produced each time contrary to the other two:

>> same? second :repend second :repend
== true
>> same? third :repend third :repend  
== true
>> same? first :repend first :repend
== false


What is FIRST on a function used for? It may be used internally, 
but does anybody use it externally? It seems more logical, if FIRST 
on a function returned the spec, SECOND the body, and nothing else.

Tonight's Moment of REBOL Zen:

>> same? :empty? :tail?
== true

Wouldn't it be better to define EMPTY? as:

	empty?: func [
		series
	][
		tail? head series
	]

That information is only available in the serialized format like 
this:

Why isn't it available using the do dialect, like:
	do [next reduce [true none 'none]]


And then you say, because DO, NEXT and REDUCE may not hold the meaning, 
you expect. 2 points:


1. Right, but is it worth the effort, if those are being redefined?

2. Why SAVE series like that at all? Why not save HEAD series and 
then maybe an offset, if you need it?

What I usually use to differentiate these is that there are literal 
values which do not have to be interpreted (only parsed), and logical 
values which have no real meaning without this interpretation.

Serialization

 in the REBOL sense, hence the quotes,  is used to give the second 
 form of data a way to be described in the first, *where its possible* 
  which it isn't at all in the case of some types (native,etc) and 
 only partially in others (objects!, functions!, etc.)   


even with these distinctions there is still a sizeable amount of 
REBOL *data* (interpreter values, not human visible source code) 
which cannot be serialized (in the real sense) in any way because 
either:  

-the notation has simply not been defined for it (cyclic series/objects, 
which is serializable in other languages)

-it implicitely depends on its interpretation (a VID dialect block 
(you cannot save the vid from the faces)), custom types (in the future))

so the way I see it is that: 
-MOLD is the counterpart to DO
-MOLD/ALL is the counterpart to LOAD.

which leads to saying that:

only MOLD/DO can effectively represent all data,  (with the caveat 
that it is extremely insecure)

only MOLD/ALL can effectively represent literal data without interpretation 
(with the caveat that it is not complete)

BOTH , are highly complex to use effectively in non-trivial cases. 
  


IMHO, if it's notation where completed, the second form could actually 
be built to represent all data, since it could be built to include 
binding hints, series reference graphing and more.  It doesn't have 
to be pretty, it just has to be symmetric.

The only problem right now, is that the serialized form of the language 
is just not complete. all the edge cases I can think of have a way 
of being resolved, especially in R3.

having cyclic references be checked and used on object/block types 
would already go a very long way.


#[block  1  [ val1 val2 ...]] ; serialized block with uid as first 
parm (only needed when it is shared in the string being loaded).
#[block  2  [ val3  #[block 1]  val4]  ; shared block
#[block  3  [ #block 3 ]]   ; self-reference


effectively shows a simple way to solve the cyclic series/object 
problem.

I'm not sure to see your point.

But If you want to see if the series are the same or not you have 
to use same?
Actually, Your trial does not  prove your claim

I'm not sure which behaviour is better though. Ie copying whole string 
vs. just the 'ranges' defined by the series values in the block.

I think it works same on all series.

I have a COPY/DEEP question:


When doing a COPY/DEEP, the first level requires that the argument 
must be a series!, port! or bitset! But when doing a /DEEP, I imagine 
that COPY traverses a series for elements and uses a different process 
than for the first level to determine whether the element can be 
copied. If it can't, it silently passes the value through.

Why can't we do that on the first level as well?

I try to think of situations, where I would need to do that. I also 
don't think, I do it often. But it's an interesting idea. I try to 
come up with some situations, where I need to copy a value, that 
can sometimes be a series, sometimes not. Hmm...

Oh shame on me! I forgot to GET the values.. Thank you.

One more question, I use COPY on objects to be able to use same series! 
values in different objects, is that right?
I mean pointing to the same series inside different objects.

In R2 I do like that:
>> o: context [a: ""]
>> p: context [b: get in o 'a]
>> append p/b "*"
>> o/a
== "*"

- "The block defines the binding".
It's against Rebol's first law. 
AFAIK binding (context) is a property of words. Series have not.

We all know you can make REBOL do just about anything. We also know 
there are a few things that trip people up (e.g. copying series values 
defined in funcs). My questions for John are: 


1) Has this behavior ever been behind a bug in any of your REBOL 
code? If so, what was the context and what was the impact (e.g., 
how did you work around it)?


2) If you got your wish, what would the consequences be? i.e., how 
would it change REBOL?

Gregg, about your questions.


1) Has this behavior ever been behind a bug in any of your REBOL 
code? If so, what was the context and what was the impact (e.g., 
how did you work around it)?


I guess, you mean series inside functions. I'm not for everything 
should do a copy, as Gabriele imply. The problem with series in functions 
is only a problem, because functions in REBOL isn't functions in 
the traditional understanding. They are semi-closures. If they were 
functions, the local values would just be on the stack. Because the 
locals live on, this was a problem for me years ago. First I solved 
it by putting COPY in series definitions, then I in many cases changed 
to just do a CLEAR, like in:

local-block: clear []


Now with the discovered behaviour regarding objects, I find the binding 
rules so complicated, that I would forget, how it works in two weeks. 
I will remember, that I have to be very careful, when making objects 
inside functions, especially if it's recursive functions. The consequence 
for me is, that I will probably put COPY/DEEP in, when making objects. 
As I won't start new big projects in REBOL, I will probably not do 
this a lot in practice.

...Because the locals live on, this was a problem for me years ago. 
First I solved it by putting COPY in series definitions...

 - sorry to chime in, but I simply have to. The issues you mention 
 (series in functions, extent of function locals) are not related. 
 For example, the extent of function locals has changed a bit in R3, 
 while the issue with series remains unchanged.

I can easily prove, that the extent of function locals is immaterial, 
when the behaviour of series in functions is examined.

John, it sounds like where you get confused, or think of things as 
bugs or design flaws, is when having your REBOL "That's funny!" moments, 
borne of deep tinkering. Aside from the "copy series in funcs" behavior, 
which I think bites many people at some point, your issues don't 
come from writing application code in REBOL and bumping up against 
REBOL's behavior. Rather, it seems that REBOL's implementation and 
design don't match your expecations in these cases, and you really 
want it to. :-)


The reason I asked about consequences is because you may want a change 
that affects other users negatively. Imagine REBOLers as being in 
one of two groups. Group A is the gurus. They have internalized REBOLs 
design, understand it deeply, and use BIND and recursive PARSE rules 
without fear. That group is very small. Group C contains everybody 
else, which includes people that don't know about using /local with 
funcs, and suggest REBOL should use  = for "assignment". They have 
never used USE, BIND, or many other functions, because they aren't 
sure how they work. Some of them know a little about series references, 
so they always use COPY to be safe. (Yes, group B exists too, but 
they are much more like C than A).


If REBOL were meant only for A users, it would be very different. 
As a designer, it seems pragmatic to make it so things work well 
for the B and C users who, when they hit a problem that requires 
advanced understanding, will work around issues with the bits they 
understand (and adding many COPY calls), no matter how inelegant. 
Group A users may suffer at their expense, but I'm OK with that, 
because I'm not one of them.

lit-path is a series, so I think the argument is sound for the latter 
result.

But yes, Henrik, COMPOSE should maybe work on path too, as it is 
a series. And maybe also on parens (also a series), where COMPOSE 
should work on parens inside.

map-each: func [

 "Evaluates a block for each value(s) in a series and returns them 
 as a block."
	[throw catch]

 'word [word! block!] "Word or block of words to set each time (local)"
	data [block!] "The series to traverse"
	body [block!] "Block to evaluate each time"
	/into "Collect into a given series, rather than a new block"

 output [any-block! any-string!] "The series to output to" ; Not image!
	/local init len x
][
	; Shortcut return for empty data
	either empty? data [any [output make block! 0]] [
		; BIND/copy word and body
		word: either block? word [
			if empty? word [throw make error! [script invalid-arg []]]

   copy/deep word  ; /deep because word is rebound before errors checked
		] [reduce [word]]
		word: use word reduce [word]
		body: bind/copy body first word
		; Build init code
		init: none
		parse word [any [word! | x: set-word! (
			unless init [init: make block! 4]
			; Add [x: at data index] to init, and remove from word
			insert insert insert tail init first x [at data] index? x
			remove x
		) :x | x: skip (

   throw make error! reduce ['script 'expect-set [word! set-word!] type? 
   first x]
		)]]
		len: length? word ; Can be zero now (for advanced code tricks)
		; Create the output series if not specified
		unless into [output: make block! divide length? data max 1 len]
		; Process the data (which is not empty at this point)

  until [ ; Note: output: insert/only output needed for list! output
			set word data  do init

   unless unset? set/any 'x do body [output: insert/only output :x]
			tail? data: skip data len
		]
		; Return the output and clean up memory references
		also either into [output] [head output] (
			set [word data body output init x] none
		)
	]
]

Hi, I found the following text part in the Replacement article: "ENLINE 
any-block!,". Forgive my ignorance, please. What exactly is ENLINE 
meant to do in case its SERIES argument is a block?

move-next 'series
 looks ok but multiply looks weird.
but ++ already works for series as you say.

++ : "Increment an integer or series index."

NEXT already test for different datatypes, as it can handle blocks, 
strings, etc.

But it's all series type. So no type checking I think. It supports 
only series and port values.

Try it in R3:
>> dt [i: 0 loop 1000 [i: i + 1]]
== 0:00:00.000251
>> dt [i: 0 loop 1000 [++ i]]
== 0:00:00.000383


Then the difference is more due to the code in ++ to tell whether 
i is an integer or a series

So we would expect things like

	next 'series

to be faster aswell than

	series: next series

But not as useful. The current NEXT can operate on values returned 
from functions, or series referred to by protected variables.

Mezzanine example:


>> my-next: func [series] [either word? series [set series next get 
series] [next series]]
>> my-next [a b c]
== [b c]
>> block: [a b c]
== [a b c]
>> my-next 'block
== [b c]
>> block
== [b c]

>> length? 4

** Script error: length? does not allow integer! for its series argument


I am proposing that this return NONE for any type which it can't 
deduce a length.


this is both usefull in practice and would make length? a truthy 
function.

this is the easiest way to know if a data element can be traversed 
via pick without having to first know if the datatype can be traversed.


the issue is that many types have indexed content but are not series 
(i.e. no "current" index).  so we can get the value or deny listing 
in one function call.

ex:

print-tree: funct  [data][
	i: 0
	either len: length? :data [
		repeat i len [print-tree pick :data i]
	][
		print mold/all :data
	]
]

we still need to add an extra if before the length? all the time.

 ... actually you would just move the IF to the native part and you 
 will use the IF also in cases where you are pretty sure it's a series 
 and want just its length.

proposal for four very usefull series functions....

shorter?: func [a [series!] b [series!]][
	lesser? length? a length? b
]

longer?: func [a [series!] b [series!]][
	greater? length? a length? b
]

sortest: func [a [series!] b [series!]] [
	either shorter? a b  [a][b]
]

longest: func [a [series!] b [series!]] [
	either longer? a b  [a][b]
]

I'm thinking, what kind of code is it that one writes, when you have 
to compare series lengths?

I just used it 10 minutes ago again... checking if two series need 
to be synchronised.

they could just be part of a delayed load series module.  there are 
many missing series handling/probing functions in REBOL.  we end 
up writing them over and over.

this implementation is order safe, removing the duplicates from the 
end rather than those in the begining

remove-duplicates: func [
	series
	/local dup item
][
	until [
		item: first series
		if dup: find next series item [remove dup]
		tail? series: next series
	]
	series
]

prefix? and suffix? just return true if a series starts with the 
same items in the same order as the second one.  
the second argument is the prefix to compare

so you can easily do:

unless suffix? file-name %.png [append file-name %.png]

the reason these are usefull is that when you chain them within other 
series handlers, you don't need to always add darn ( ) around the 
operators.

unique returns a new series.

I was just curious, because even with new series unique is much faster.

its a shame that all "set" functions make new series.  we could just 
easily copy before calling unique:
new: unique copy serie

though there is a lot of memory overhead for large series, I'd rather 
have a refinement on all sets probably   /only  or something similar, 
to have them work "in-place"


come to think about it, maybe we could make a CC wish for this, seems 
like its been a topic of discussion for years, and pretty much eveyone 
agrees that both versions are usefull.

SWAP is another interesting one... takes two series and swaps their 
content, in-place.

INTERLEAVE is a very usefull function, using two series and mixing 
them up with many options like counts, skip, duplicates, all cooperating.

anyway, I really think that we should accumulate all of the series 
functions we are using (even the more obscure ones) and make a big 
standard series handler module in R3.  it helps people who are learning 
REBOL since they don't have to figure out as much how to build these 
(somethimes non-obvious to implement) funcs.

See http://issue.cc/r3/1573for remove-duplicates and the reason 
it's not as good an idea as you might think. It turns out that the 
set functions have to allocate a new series to do their work (for 
series larger than trivial size), even if they were changed to modify 
in place. So you can't avoid the allocation; might as well benefit 
from it.

its a good idea, because I can't copy the series, its linked in many 
places.

It has to allocate another series anyways, as the set functions do 
hashing. In-place is just for convenience, not to save memory.

Does DEDUPLICATE *have to* create a new series. How inefficient would 
it be to SORT the series then REMOVE duplicates starting from the 
TAIL. Inefficient as a mezz, but as native?

To find out what is wrong, just write an "in place" version of Deduplicate 
in Rebol, divide the time needed to deduplicate a 300 element series 
by 30, and compare to the algorithm (in Rebol again) allowed to use 
auxiliary data.

Or, to make it even easier, just use an "in place deduplicate" written 
in Rebol, divide the time to deduplicate a 300 element series by 
30, and compare to the time Unique takes (Unique uses aux data, i.e. 
a more efficient algorithm)

I have my own versions of the series comparison funcs Max proposed 
on 27-Jan. My versions of SHORTEST and LONGEST take a block of series 
values, and return the given item by length. I don't use them much, 
but there are times they are nice to have.