World: r3wp
[Core] Discuss core issues
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BenBran 16-Jan-2009 [12082x2] | Yes this helped thank you. |
I'll look some more later, but what seemed to fix it was the built in function 'to-rebol file' :-) | |
Janko 19-Jan-2009 [12084] | can I ask if you know any other options for rebol to talk to other independant processes on linux? For example could I use something like named pipes? |
Chris 19-Jan-2009 [12085x2] | There was a script for Rebol->Arexx once called Pipebridge. Wonder if it's applicable to Linux? |
Rebol<->Arexx | |
btiffin 19-Jan-2009 [12087] | Janko; I'm pretty sure a mkfifo named pipe will work; BUT as usual, either end borks, the other end hangs. |
Janko 19-Jan-2009 [12088x4] | Chris: I googled about what you said but didn't find any source, but interesting.. this stuff was running on amiga at the time :) |
btiffin: I am newbie at linux... you mean I can make a named pipe in command line with mkfifo and then rebol uses that as a normal filename to write/read from it? Similarly the other language has Unix package and can make named pipes by it's own... can rebol create pipe too? (sorry if I got it all wrong) | |
about hanging, yes I read that write does not happen untill there is a read at the other side and vice versa so I was thinking if there is some king of timeout possible.. | |
hm.. but why is it then called fifo if read needs to happen at the same time as write, I thought it's some sort of fifo (first in first out) stack/queue | |
btiffin 19-Jan-2009 [12092] | Well normally fifo files are created in blocking mode, so yeah a write won't complete until a read occurs and a read will wait for a writer (by default). I'll be honest, I've not done this from REBOL, but with 2.7.6 and LOAD/LIBRARY freed, we can do any libc6 calls that we want, so you should be able to set a non blocking mode and get true multiple writes and reads that will return empty if no data is queued. For OpenCOBOL I implemented POSIX Message Queues; as MQ_NOTIFY will make a callback when the queue goes from empty to non-empty and you don't have to worry about spinning on a read. If you don't mind playing with make routine! take a look at mq_open and friends (man mq_overview) it might offer more control for IPC. |
Janko 20-Jan-2009 [12093x2] | thanks btiffin for such great explanation, yes I was looking at message queues too at first but then someone proposed pipes and they do seem more accessible/simple to start in a way. |
Is there any article or blog post about 2.7.6 being able to load native libraries? I searched and couldn't find any info on this.. I found docs for REBOL/Command/SDK version so this would be a place to start experimenting probably | |
btiffin 20-Jan-2009 [12095] | Janko; yep. It's weird, docs wise, but make routine! is a new bonus layer that hasn't made it's way to the main documentation. Our good Gregg is a goto guy when it comes to knowing some of the foibles invovled. If you like learning by example http://www.rebol.org/cgi-bin/cgiwrap/rebol/view-script.r?script=capture-screen.r or http://www.rebol.org/cgi-bin/cgiwrap/rebol/view-script.r?script=capture-screen.r There are other examples. |
Janko 20-Jan-2009 [12096] | great, I love learning by example :) .. btw .. both of your links are the same I think |
btiffin 20-Jan-2009 [12097] | Sorry Janko; the second was supposed to be http://www.rebol.org/view-script.r?script=sqlite3-protocol.r that's what I get for not reading what I'm writing. |
Janko 20-Jan-2009 [12098x2] | oh, great just what I need... I was fixing/modding a sqlite binding in factor already |
so I can compare a little , and I will probably need it also | |
[unknown: 5] 21-Jan-2009 [12100x2] | >> a: copy [] == [] >> b: 'test == test >> append a :b == [test] >> type? first a == word! >> find a 'test == [test] >> c: ['test] == ['test] >> find a first c == none |
That just bothers me. | |
Pekr 21-Jan-2009 [12102] | type? first ['test] == lit-word! |
[unknown: 5] 21-Jan-2009 [12103x5] | Yes I know. |
My point is that REBOL is not consistent. | |
Why can I do a find using a lit-word but not get results when using the lit word from a block? | |
find a 'test works but find a first c doesnt. | |
I would have to use find a to-word first c to get a match. | |
Pekr 21-Jan-2009 [12108x3] | I think it is a bug. But we will probably see gurus trying to find an excuse, why sometimes you can't code in REBOL different way than to simply try some stuff in console ... |
And - imo if RT would post some formal specification to the language, we could fix some gotchas and surprises, not trying to find academic theories, why it work certain way ... | |
insert as an operation does not preserve datatype. It reduces litword to word. Not sure there is a reason to do so ... | |
[unknown: 5] 21-Jan-2009 [12111] | Yeah, that to me would be a bug. |
Henrik 21-Jan-2009 [12112] | >> append [] to-lit-word 'a == ['a] |
[unknown: 5] 21-Jan-2009 [12113x2] | Yeah Henrik but that is a workaround really. |
the 'a was already a lit-word to begin with. | |
Pekr 21-Jan-2009 [12115x2] | Henrik - but - that is exactly the excuse I was talking about |
why should I use to-whatever for one datatype, but not for the other one? | |
Henrik 21-Jan-2009 [12117x2] | the question is probably which operation is more common. |
I'd bet Carl did it that way, because it is something he does more, than the other way around. | |
Pekr 21-Jan-2009 [12119] | hmm, but it can really lead to surprises, as Paul got - trying to find something by reference .... |
[unknown: 5] 21-Jan-2009 [12120] | To me it is one of the exceptions to the rule things. With REBOL you gotta have all these exceptions to the rule. |
Henrik 21-Jan-2009 [12121] | I'm not defending it, just trying to come up with a theory. |
Pekr 21-Jan-2009 [12122] | ... but yes, REBOL is dynamic, so it might be a problem, to have all cases working as expected ... |
[unknown: 5] 21-Jan-2009 [12123] | lol |
Henrik 21-Jan-2009 [12124] | because I know that Carl works alot more with cases of usage rather than theoretical correctness, as long as the result isn't completely backwards/illogical. |
[unknown: 5] 21-Jan-2009 [12125] | Well, at least I know how to get around it which is why I just mentioned that it "bothers me". |
Pekr 21-Jan-2009 [12126] | Now someone clever should answer, if it would have some consequences to not reduce lit-word upon block insertion? |
[unknown: 5] 21-Jan-2009 [12127] | But to me Henrik the append or insert should be able to look at the argument and see it is already a lit-word and append it as such. |
Henrik 21-Jan-2009 [12128x2] | I was going to write something clever about that, but I think trying to fit such a change in has some pretty big ramifications for how words are used in REBOL. :-) |
anyhoo, I can't defend it, so I'll let BrianH take over. | |
[unknown: 5] 21-Jan-2009 [12130x2] | Heh. |
Well at least you didn't try to give excuses. | |
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