World: r3wp

what are you talking about? You want to change the meaning-of, or 
replace | symbol? :-)

I'm having trouble typing because of AltME freezes.

Pekr, *you* want to change the | symbol. Or rather, you want to do 
something exactly equivalent, changing the corresponding & operation 
to STAY.

| is visually good ... it is like wall dividing slots ... it fits 
... the + is more complex. Guru stuff, which we will have difficulcy 
to explain. Maybe it can't be done the other way. So - user has to 
learn what does it do by examples, get used to it, and then maybe, 
he will understand it, once he sees it in the code. The only question 
is, if eventually naming it, or changing the syntax to achieve the 
same, could be done more elegantly, which I start to doubt.

There is NO & operation ...

... not in current parse. Just in parse theory. I don't care about 
the theories.

... you are just using those excuses. Simply put - if you want STAY 
instead of AND or &, then we will throw it back to you, accusing 
you of the need to change already used | symbol by giving it a name 
:-)

Proposed. Originally, Peta renamed & to AND since he (she?) thought 
that a spelled-out word was required by the dialect. Then I changed 
AND to AT since I didn't know infix operations were possible. Then 
Carl changed AT to STAY, since he didn't see the point. Then he realized 
what the operation meant and changed it back to &, what it should 
have been in the first place since it is the opposite of |.

I was always thinking about parse being an alien in the parsing world. 
It was just Peta who introduced us to the TDPL, PEG and other terms, 
trying to fit it to various theories. My opinion is - if such changes 
will not lead to eventual direct usage of already existing parse 
rules somewhere out there, then I don't really care about all those 
theories. We are already unique, and I don't want parse to go back 
adhering to some "standards". It feels the same, like changing feel, 
face, facet and all the naming to fit more general naming convention 
of the outer programming world ...

TDPL wasn't used, and PEG was created to describe parsers like PARSE, 
and 5 years later than PARSE was.

The rest of the world is catching up with where PARSE has been for 
10 years.,

And the reason we are adopting operations from PEG, TDPL and GTDPL 
is because they fit into PARSE's semantics and are useful.

It's just filling in the blanks.

sorry NOT for +

I just want parse to stay readable for average man. The more symbols 
we add, the less readable the code might be at first sight. We should 
be carefull, or Larry Wall steps-in commenting R3 arrival, stating 
that R3 added even more punctuation :-)

although for "&" I agree, it really is just a single letter symbol 
which means AND, which in this case is right.

especially if the rule is infix (which it seems it will be  :-)

Perl 6 has already surpassed PARSE in its own category: their "regex" 
engine is a PEG parser, and has useful stuff we're adding now.

parse hasn't really evolved for what... 10 years?

PARSE was unique, but is becoming less so.

I always thought it would be one of the first thing R3 would work 
on.

PARSE added OPT and BREAK more recently than 10 years ago, and bugs 
were fixed, but otherwise unchanged.

I do thing BRANCH is the better term for the either / + keyword

thing = think

or  BASED-ON    :-)

This seems like a really good candidate for a symbol, but finding 
a prefix one is tough. If it could be postfix we could use ?, or 
even +. Postfix would look like infix, or rather like C's ?: when 
combined visually with the next | character.

I saw BASED-ON as a prefix symbol.

based-on rule | yay | nay

Then [a ? b | c] would be equivalent to [a b | not a c].

possible name for +  might be: ELSE or OTHERWISE :-)

Not in prefix it wouldn't be.

brian:   post fix ? is  actually not bad... and since condition rule 
is traversed anyways (either its true or false) .... it probably 
doable...

yeah so far, the only prefix term which reads well IMHO is BASED-ON

What I don't know is whether it is possible to do postfix anything 
- failure might cause backtracking before the ? is reached.

I really like, like in the end we are going to decode it for the 
users in documentation - "Now, you parse user, please read following 
syntax as - EITHER rule A is matched, THEN B is evaluated ELSE C 
is valuate" ... yet we will pretend, that we came up with some cool 
symbol to express what we just had to explain in human words :-)

no we won't use either... cause that is not what is happeneing.

;-)

attempts to match a rule, AND runs first rule if it matched OR second 
rule if it did not.

no? how do you explain [a b | not a c] then? I thought that - EITHER 
(IF) A is mathed, then B is being matched, or C is being matched 
(by being matched I mean - evaluated, hence might fail)

Max - who decides, what EITHER mean in parse context? We do. I can 
say - don't use COPY, as this is not what is happening (in REBOL's 
copy function semantics equivalence)

but copy actually does copy what is being parsed.  either isn't comparing 
a value like the if PARSE statement.

Max - you are NOT in REBOL level, so free yourself from pedantic 
"EITHER uses this syntax" equivalence, or dismiss COPY keyword too 
- it absolutly does not fit REBOL and even today on blog I had to 
fix Ingo's type, where he ommited to provide parse COPY with word 
to copy to ;-)

but in the end,  I just dont want it to be +  which is the worst... 
 even  "?"  prefix is better

Once again - free yourself from REBOL, gee. Who said said EITHER 
should compare anything? Copy breaks normal copy rebol logic. VID 
'at command is completly different in semantic meaning to REBOL 'AT. 
So - how is that that for EITHER we do care about what it means in 
REBOL? The word EXACTLY expresses what you are doing ...

If you want to be so pedantic, let's exclude all word from parse, 
which have different meaning in REBOL. It means COPY, TO ... any 
other candidate? ;-)

Today I posted more philosophical topic, and Carl noticed it - we 
ares shooting ourselves in the foot. Here's what I posted:
-------------------

There will always be problem with dialects, if they contain the same 
keyword names as REBOL functions. So we have to somehow live with 
that.


So the question is, where to introduce new name and why, just to 
be different, and where to not. E.g. parse 'copy keyword has already 
different semantics to REBOL's one, or VID's 'at has different semantics 
to REBOL's one. Now can users be confused? It depends.


I try to think about each dialect in the context of the dialect itself 
- so the only measure for me actually is, when reading the source 
code (or trying to understand one's), how quickly I am able to understand, 
what is going on?


But then we could as well replace 'stay by 'save-position, 'of by 
'any-of, 'if by 'only-if, etc., which would imediatelly map the meaning 
to what the keywords are really doing. But we are somehow mysteriosly 
looking for one-word-only-mantra naming convention, and I suppose 
it is already our style, and we will not change it :-)


... so, the topic is a little bit more abstract - it is about contexts, 
and user/programmer switching between contexts, and his/her ease 
of understanding of the code.


In above case, all 'if, 'check, 'either are OK, even if their semantics 
is a bit different to their REBOL counterparts.

I do agree

your rant towards EITHER not fitting anything breaks the initial 
purpse dialecting was brought to REBOL! And the meaning is - the 
same word, might mean different things in various contexts. We don't 
care for VID to use potentially the same keywords to REBOL functions, 
let we do care somehow mysteriously about PARSE to NOT use the same 
keyword naming as REBOL functions. Let's judge EITHER by its name, 
not by its REBOL level meaning.

Yeah, the name EITHER, exactly the reason I've had a problem that 
proposal since it was proposed in December.

The name EITHER was why I put "maybe" on the proposal.

If the english meaning of EITHER does not describe well what is intended, 
then let's not use it, otherwise let's use it. I noticed Carl created 
scenario, which allows to be really flexible. If no word can fit 
its meaning properly, then let's use the symbol. If we can find word 
for it, which will help users to imediatelly see, what the code does, 
let's use the name with no prejudices ...