World: r3wp

but what's the point of AND   everything is already AND by default. 
just put them in a block, so they are and.  when you read & it doesn' 
appear that the parser isn't moving forward.

EITHER doesn't work like EITHER, and it needs to be prefix, and use 
the semantics of Carl's + proposal or it won't work. Suggest a name 
to be used instead.

the only thing he's complaining about is putting things in a block... 
what's the problem with that?

either [] [] []  can't be more explicit thant that... what is the 
problem with blocks?  or a paren for the condition?  really I don't 
get it.

If you see | it doesn't say that the parser is backtracking either. 
& is the opposite of |.

To use a tool it sometimes helps to know how. Assume some basic reading 
of docs will be needed to use a programming language.

BrianH: COPY is NOT COPY, so what?

EITHER doesn't need to skip past |, so pick another name. It will 
be prefix. Suggest it in the 249 blog.

This is not the same thing as a programming language conditional 
- it is a GTDPL concept.

Just like CHECK isn't like IF, it's like ASSERT.

I can't suggest anything, as I don't understand what the article 
is all about. Stuff like  - "advance past the next 2 alternate rules 
on failure."

And I can tell you - if I - the occassional parse user can't easily 
decode the meaning by just looking into the examples, there will 
be many such users ...

... and - I don't buy arguments like - it is a GTDPL concept. Our 
(parse) users will not care about such statements. We are not here 
to adhere to any academic theories, but to make things usefull. If 
we wanted to adhere to what the world uses in parsing area, we should 
go the regular expressions route ...

OK, enough. I will wait how it turns out. Let's just remember, that 
we can go our own way, as parse already does. No need to turn it 
into obscure other whatever-parse-old-70ties-theory-suggests things 
...

Do you get that the concept needs a name, and that obscure concepts 
also need names? The standard syntax for this concept won't work 
in REBOL, and the only other comparable parser is the one in Perl 
6, and we can't use that syntax either, or its semantics either (it's 
compiled). This *is* guru stuff - people get PHDs about parsing. 
Carl's proposal for +'s semantics is the way that this has to work 
given how REBOL parsing is implemented.

the thing I don't  *get*  maybe you can explain, is where he adds 
the increment to the '+ ... what does that mean... really I don't 
grasp it.

Now, *that* is obscure. Noone else does that, not even Perl 6. That 
is unique.

but what does it mean?

dang ... I just *got* it...

either  [ a | b ]  [ c ] [ d ]

I don't mind the possibilities, I do care of naming and how long 
does it take for me to interpret it. If we go + route, we can change 
NOT to !, add &, II, >, -->, etc. :-)

NOT is not going to be !, for the reasons I already mentioned.

you see? looking at what Max just posted, I *imediatelly* can understand, 
what does his code do.

& makes more sense than STAY, because it relates to |. Both backtrack.

still don't see why the use of blocks is evil when its the way of 
parse for everything else.

Now I don't understand once again - if you are suggesting just changing 
the name of STAY to &, then please DON't do it!

Maxim, the a's in Carl's examples aren't involved in the expression.

Pekr, no, Carl was thinking of changing AND to STAY, but decided 
against it when he figured out how to make it infix.

Maxim, "everything is already AND by default" is not true. Everything 
is "and then" by default, which is AND with moving forward. What 
we need is AND without moving forward. An infix & handles that nicely, 
and is the opposite of the infix | meaning OR.

Ladislav just cheared to how Carl is precious about naming, and he 
liked STAY and QUOTE. STAY imediatelly expresses its meaning. Changing 
to to AND makes the situation only worse ....

So you want to rename | too?

brian  yes... I am wrapping my head around this... but I have to 
re-read the STAY proposal before getting too vocal... I'ts been to 
long since I've read it.

I actually wouldn't mind it being 'OR

(bts... about the 'a yes I didn't use the same vars in sequence... 
sorry)

[+ a |  b | c] is equivalent to [a b | not a c] but without the overhead 
or side effects being executed.

So, do you have a name for that?

This is really just - EITHER A [b][c], no?

[a b | not a c]   actually it should say... [ [a b] | [not a c]] 
  sorry but the |  doesn't roll back the a it will only roll back 
the b... its bit me too many times

No, because the a is not a condition, it's a rule.

what brian means is that the rule is consumed.... its just something 
that has to be understood.

Maxim, the a is rolled back too.

COPY is not COPY too, so what? REBOL copy value - PARSE - copy variable 
to-rule

it shoudn't be called EITHER specifically for this reason.

Brian - this is not easy to name ...

not in my experience... really it says it should and it works.. . 
until something screws it up... its happened to me COUNTLESS times... 
I've always had to put my rules in blocks to make sure they don't 
get fucked up by "|"

btw - how will you explain it to the user? Maybe it is just too new, 
but unless you provided me with [a b | not a c], I was not able to 
depict [+ a | b | c]

OK, let's try an easy one. Try to explain + without usingh the word 
"addition". Symbols are sed for a reason.

but its just being picky... the real thing... is what is evil about 
blocks?

but you see its not an addition.  its "go-over-this-and-accumulate-failure-or-not"

here... we have the precise name... its over 30 chars long   ;-)

we went too far. We should accept Steeves proposal - allow EITHER 
to be embraced as using condition OR the rule. Single as that. You 
can't beat the EITHER name. Thinking here and there, I can't imagine 
how + could be named, with the used syntax ...