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World: r3wp

[!REBOL3]

BrianH
14-Nov-2010
[6132x2]
Doing a block with set-words set to a local context and initialized 
to none: let collect-words/set block none block. Still correct if 
there are no set-words.
Yeah, working with any-word! is good. I first read any-type!, so 
that is why I rehashed the unset argument, sorry.
Ladislav
15-Nov-2010
[6134x2]
My note to the "rehashed #[unset!] argument": I like the "The whole 
point of #[unset!] is to trigger errors" formulation. Nevertheless, 
it is broken in a big way by USE and function contexts. Only any-object 
contexts adhere to this convention now, so it is an error to write.:

context [
    print a
    a: 1
]

, while a corresponding

use [a] [
    print a
    a: 1
]

would be an error in R2, but not in R3 anymore, while

do has [a] [
    print a
    a: 1
]

was not an error even in R2.


Therefore,  "The whole point of #[unset!] is to trigger errors" is 
true, but, as demonstrated, the #[unset!] value is sneakingly losing 
its point to the extent, that it is becoming negligible. BTW, this 
is one more "arms race", which a protection measure is losing when 
confronted with the freedom of a programmer to write code he likes 
to write. The previous victim of this race in the datatype space 
seems to be the #[none!] value (at least to me).


I do not object, since due to the changes the #[unset!] value is 
becoming more of an annoyance, than a useful bug protection. And, 
there are other benefits, like increased compatibility between USE 
and functions, exactly as the discussion revealed, as well as the 
fact, that the protection was never as useful as it was planned to 
be.
What I see as the only problem of #[unset!] losing this arms race 
is the fact, that we will still have "debris" in programs like GET/ANY, 
SET/ANY, LET/ANY, even after the resons to have them become sneakingly 
nonexistent.
BrianH
15-Nov-2010
[6136x3]
Yeah, but I'm still glad to have unset for exactly the reason it 
was intended for. Though the new unset in R3 is the unbound variable, 
which is even more useful.
I need some error to trigger to point me to my typos :)
I suppose you would consider the unbound variable errors to be the 
next round of the arms race though. It is getting to be a tiresome 
metaphor :(
Ladislav
15-Nov-2010
[6139x3]
Maybe I surprise you, but not. The reason why is, the unbound variables 
are not a "new datatype to enforce something", they are an existing 
datatype used for a reasonable purpose, and not starting a new round 
of "war" introducing some GET/WHATEVER.
But, being at it, there is one annoyance I perceive:


1) the variables bound to a function context don't cease to exist 
even when the function is not running
2) code like:
    f: func [/a]['a]
    block: [a]
    bind block f

do not work, while I can do such a bind on my own without needing 
any permission:
    change block f
So, this is clearly just an annoyance, and not a useful feature.
and, being at it, yet another annoyance of exactly the same kind 
is:

o: make object! [me: 'o]
error? try [bind 'self o] ; == true
bind [self] o; == [self]

, i.e. again, one can bind as wished, so the "feature" is just meant 
to be annoying, not useful
Gregg
15-Nov-2010
[6142]
+1 for consistency.
Maxim
15-Nov-2010
[6143]
+1 for consistency, as long as functions keep their implicit initialization 
to none.  


to me this is a feature, one which I have relied on in all my REBOLing.
Gregg
15-Nov-2010
[6144]
Yes, the none behavior makes sense, for USE as well, because you 
have told it you expect certain words to be used.
Ladislav
15-Nov-2010
[6145]
USE3:USE2 = 7:0
ChristianE
15-Nov-2010
[6146]
8:0
BrianH
15-Nov-2010
[6147x2]
Pleasantly surprised, thanks :)
About the annoyance, that is a side effect of two things combined:

- Starting with R2 we got direct binding, rather than dynamic binding, 
for a 30X speedup IIRC.

- Starting with R3 we got stack-relative contexts for functions, 
for security, task safety and better recursion safety.


You can't have the words in functions lose their bindings once the 
function returns because they will need those bindings the next time 
the function is called, and you can't rebind because definitional 
binding depends on the order of binding operations. So instead the 
context becomes invalid. It's an annoyance, sure, but it is more 
of an understandable side effect of some *extremely* useful features.
GrahamC
15-Nov-2010
[6149]
Do we need an oid type?  For instance this is my OID 1.2.826.0.1.3680043.8.1178.
BrianH
15-Nov-2010
[6150]
What is that used for? And do you do math with it?
GrahamC
15-Nov-2010
[6151x2]
it's like an ip address but it's used for real world objects
http://en.wikipedia.org/wiki/Object_identifier
BrianH
15-Nov-2010
[6153x2]
It sounds like we can use the same approach as with the IPv6 addresses: 
string syntax, binary data.
Datatypes aren't necessary as often as you think.
GrahamC
15-Nov-2010
[6155x2]
and that is?
And yes, you will want to do some math on it
BrianH
15-Nov-2010
[6157]
Is it critical that they get syntax? It looks really ambiguous with 
tuple syntax. It looks like a user-defined datatype would help here, 
as they can do math with the actions but won't get syntax.
GrahamC
15-Nov-2010
[6158]
get syntax?
BrianH
15-Nov-2010
[6159x2]
Be loaded in literal form by LOAD. That is the only advantage of 
a datatype! over a utype!.
The same could be done with IPv6 addresses. But both of those could 
have all of their support functions implemented in a module with 
regular functions and commands in it and you would have the same 
functionality now, before utypes start working.
GrahamC
15-Nov-2010
[6161]
no, don't think it's needed
BrianH
15-Nov-2010
[6162]
So we don't need to do an OID type, but having support for OID would 
be helpful. Good catch :)
GrahamC
15-Nov-2010
[6163x3]
I guess the sort of operations you want to do are to compare oids, 
add leafs etc
Here's a possible example of use.  Carl could be assigned an oid, 
and then he could sub assign an oid from his root to Andreas.  Andreas 
can now uniquely identify each of his builds with an oid as can Carl 
with no overlap.  We can tell from the tree where they lie.
And likewise Henrik can release his own GUI builds with his oid set
BrianH
15-Nov-2010
[6166]
We can do that now with names and usernames. Who uses OIDs?
Andreas
15-Nov-2010
[6167x4]
more or less arcane protocols do :)
like snmp
or x.509, or ldap
and most likely some super complex healthcare standards do, which 
is where graham enters the picture :)
GrahamC
15-Nov-2010
[6171]
yeah ... the CDC uses OIDs for everything now
BrianH
15-Nov-2010
[6172]
So, sounds like a good idea for a community utility module :)
GrahamC
15-Nov-2010
[6173x2]
I had to get an OID for my medical app
so I can report anthrax cases :)
BrianH
15-Nov-2010
[6175]
Are they objectifying you at work, Graham?
GrahamC
15-Nov-2010
[6176]
this is object identifer programming
BrianH
15-Nov-2010
[6177]
Nevermind, bad pun :)
GrahamC
15-Nov-2010
[6178x3]
for instance , Y means yes according to the following code system 
2.16.840.1.113883.12.136
which is in the HL7 directory
If you want a free OID, you can apply for one from IANA http://pen.iana.org/pen/PenApplication.page
Pekr
15-Nov-2010
[6181]
IIRC OID is used for snmp (simple network management protocol), and 
this one is really big and important ...