World: r4wp

(does not sound reasonable)

Ladislav - I don't care if I am able to use some guru system - it 
either works for me as a user, or it doesn't. Reserving something 
for gurus should not be the point. Not in Rebol imo ....

Objection of Doc was something like that it will slow parser, allow 
inappropriate use of parser, and hence could shed bad light on its 
performance, because instead of learning how to properly use it, 
ppl will use those idioms ...

I do not "reserve" anything for anybody. I just know that "using 
trial and error" is (unfortunately) not the way how to get things 
done.

But - I have a suspicion, that Doc is not aware of most R3 enhancements. 
Proof is, few months back BrianH just pointed him to the R3 wiki 
enhancement parse doc. So I expect him to study it. Not all enhancements 
are imo bad ...

Ladislav, so simple question - so would you discard to [a | b]  from 
the R3? Do you find it as a performance penalty, or teaching ppl 
wrong habits, preventing them to actually understand, what is parse 
about, or something like that?

I think, I mostly used string parsing in R2, and got around such 
problems that way.

would you discard to [a | b]  from the R3?
 - no, I actually support it being there

But I see the benefit of TO [a | b].

Well, we will see, what is Red's parse going to be about. I expect 
Gab to implement his compile rules, or something like that. Actually 
I never investigated his system, so we might get a bit different 
stuff, who knows ...

Do you find it as a performance penalty, or teaching ppl wrong habits, 
preventing them to actually understand, what is parse about, or something 
like that?

 - The answer is "no" to all the above questions. It is neither a 
 performance penalty, nor teaching people wrong habits or prevent 
 them to actually understand...

I only have R2 parsing in World today, as my initial goal was just 
to get to a point, where my R2 programs could run. It would for sure 
be an idea to look at the extensions at some point. And then desicions 
has to be made, if it should all be with extensions, if there should 
be more than one way of parsing, if it should still be mezzanine 
or made in C, or maybe some JIT compilation. Many options. :)

If it's not a performance penalty (and it certainly might not, I 
haven't looked closely at it), then I see no reason not to have such 
good ideas as is found in R3 parsing.

And then there is always the problem of getting it documented, because 
people talk different 'languages'. Maybe it's an idea to break documentation 
up in 'the basics', 'advanced' and 'expert' stuff.

I remember now, how I solved my TO [a | b] situations in R2. It's 
what I call 'positive' parsing, where I all the time look for a positive 
all the way to either a or b is reached. It's easier to just let 
it skip to either a or b, whatever comes first, yes, but I was able 
to parse about everything the other way.


I need to look through all the R3 extensions to parse some day, when 
parse needs an overhaul in World. I guess, having parse as a mezzanine 
is a good thing to port it to also Red or other languages?

Geomol - there's nic doc here - http://www.rebol.net/wiki/Parse_Project

cool, thanks! I also know of this:

http://en.wikibooks.org/wiki/REBOL_Programming/Language_Features/Parse/Parse_expressions

I lost track of, what REBOL docs are good and up-to-date.

I imagine Doc will profile things if performance becomes his argument. 
I support what makes it easier to use PARSE to get the job done, 
though sometimes there may be confusion between those who understand 
parsing at a deep level and those who don't. I would rather have 
support for TO [a | b], and other rules, even at the cost of them 
having lower performance, versus people not being able to do the 
job at all. In docs, we can note the tradeoffs, and people can optimize 
if necessary.

Agreed

Doc, is your plan for Red PARSE to use R2 dialect, or R3's?


R2 dialect plus a few of R3 additions that have no R2 equivalent 
or very complex R2 equivalent. Please don't ask me to make lists 
now, as it is not the current focus. When time comes to implement 
PARSE, we'll discuss every feature in detail if needed.

Is Gabriele still going to do the parse implementation?  Or was that 
just a rumour?

It was supposed to be a private info, but somehow private chats are 
leaking massively here these days. :-)

Blame Pekr!

Gabriele was mentioned here in the past, I believe :-)

Yep

For your information, http://en.wikipedia.org/wiki/Parsing_Expression_Grammar
gives some PEG related info that could be used to explain how REBOL 
uses PARSE to do almost ALL the same work ... and presents some fundamental 
differences with CFG and RegEx parsing. As you'll see for some simple 
(and not so simple) grammars REBOL Parse function works on par with 
the PEG theory.

Is it a good think, that REBOL works on par with PEG, or are there 
more benefits in CFG parsing? Both methods have pros and cons, but 
maybe one of them would have advantages in relation to REBOL (or 
the REBOL way of thinking)?

Geomol - there is also some reasoning in the rebol.net wiki document 
I posted. There was u user, Peta, who helped with the process, then 
disappeared ...

Thanks, Pekr. Reading it now...

#[[Geomol

Is it a good think, that REBOL works on par with PEG, or are there 
more benefits in CFG parsing? Both methods have pros and cons, but 
maybe one of them would have advantages in relation to REBOL (or 
the REBOL way of thinking)?
]]Geomol


- indeed, no need to reinvent the wheel, the arguments why the Parse 
expressions are the Rebol way have been summarized already

My view is, that if the first wheel wasn't round but oval or square, 
then it might be a good idea to reinvent it. And in programming, 
it's in general a good idea to rewrite every few years.


But the problem with REBOL is found in a different place. It's about 
making a solid foundation to build upon, and to make sure, each level 
of the tall building is solid before moving on to the next level. 
Much like it was described in "R3 Alpha Test Priorities":
http://www.rebol.net/wiki/R3_Alpha_Test_Priorities

Therefore it's cool to see a project like Red, that seems to be well 
thought trough, and where there is slow but (I feel) solid progress 
towards a goal.

As opposed to that, my opinion is that being pointed to a documentation 
you should read it before presenting opinions that "it may be oval 
or square" before even trying to read it.

...and by "reinventing the wheel" I meant just thinking whether PARSE 
has the properties desirable for Rebol, since that has already been 
documented sufficiently as far as I am concerned

Are you trying to shut me down?


I asked for Gerard's opinion about PARSE, if it should be more of 
a PEG or CFG parser. I read him, as he commented on R2 PARSE, that 
it works on par with PEG theory.

Yes, but he also pointed you to the documentation you did not read

Gerard pointed to
http://en.wikipedia.org/wiki/Parsing_Expression_Grammar

, which I read. Therefore I asked him about his opinion.

Cheer up, pal! No need to pick on others like that.

Aha, reading the above discussion, my apologies must go to Pekr since 
it was him pointing to the documentation summarizing the properties.

No need to apology in this case, I am used to more heavy calibre 
from Ladislav, when I tend to talk nonsense :-)

Parse: I simply wanted to try porting Topaz's PARSE. Not sure if 
that would or could become the built in one. I hope to still be able 
to do it eventually... we'll see.

There are some suggestions, for the next version of Windows8, after 
the Blue (8.1), to be called Windows Red. Now we need to release 
some juicy Red apps to confuse ppl :-)

Is there a Blue language? If such a language was made, maybe it should 
be the exact opposite of Red? (Whatever that is.)

Yes, there is :-) http://en.wikipedia.org/wiki/List_of_programming_languages

Red nor World are there ...

Blue is a system for teaching object-oriented programming, developed 
at the University of Sydney, Australia. It is an integrated development 
environment (IDE) and a programming language. Blue has been used 
for teaching since 1997. The development was stopped in 1999 when 
one of its principals, Michael Kšlling, began applying the IDE design 
to the Java programming language, resulting in BlueJ.


Sydney, Australia. Opposite side of the World, opposite of Red. :)

Pekr, it is just up to you for Red to be in that list as we already 
have a wikipedia page for Red. ;-)

FYI, I will work on fixing the last bugs added to the tracker today, 
then I'll go back to the work on Android port.

Sorry for stupid question, but by tracker, do you mean Github Issues 
section? Or is there any other bug tracker you use?

Github's bugtracker.