World: r3wp
[Core] Discuss core issues
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Pekr 31-Jul-2007 [8596] | really? What is that refinement there for then? :-) Well, it might be understandable - read in opposite to open just can't be so fine-grained ... |
Henrik 31-Jul-2007 [8597] | it probably depends on the webserver, if it will deliver only part of the page or not. |
Pekr 31-Jul-2007 [8598] | IIRC I tested open/part and skip and it worked, but it was long time ago ... |
Gabriele 31-Jul-2007 [8599] | R2's HTTP does not support that kind of things. |
Geomol 1-Aug-2007 [8600] | I'm so irritating happy today! :-D (You may not be able to say such in english, but it works in danish.) |
Henrik 1-Aug-2007 [8601] | it does? :-D |
Geomol 1-Aug-2007 [8602x2] | Ops, wrong channel, that should have been in the "Chat" group. |
Oh my, I'm just irritating! :-) | |
Pekr 4-Aug-2007 [8604] | Today I was thinking about REBOL paths and namespaces navigation "problem". I would like some clever persons here, to educate me a bit in that area. So far I think, that REBOL breaks on some path rules, of course it depends, upon what "philosophy" you provide as an explanation. So, I was thinking about namespaces/paths/context, as of a tree .... So, all words are defined in top (global) context = root, right? (excuse simplification). Then comes first question - how can be following valid?: a: 5 b: context [print a] My objection is, that from the point of 'b "node", there is no 'a. So, my explanation is: 1) in the case of directory, we would use ../a 2) or we should go via root reference - b: context [print /a] 3) we create "philosophical" rule, stating that global (top) context words are propagated to subsidiary nodes (contexts) I don't mind case 3), if such rules are well defined, and it will come, once we switch to modules. How did I came to think about above? I have somehow aesthetical issue with REBOL, when I look at e.g. scheme code in R2. It is full of awfull system/words/word references. I don't like it. What I would like to see is to have some abbreviations. I know that we can do e.g.: _print: system/words/print My question is, if we could have some more abstracted solution? Do you remember 'with keyword? I don't remember how it worked, but I would like to have some ability to "bind" particular word from existing context to actual context: bind system/words node here, so that I don't need to use paths (kind of like when you create links in unix filesystem hierarchy .... Of course, here we go - we could easily get some colision, e.g. if target context contains the same words. But maybe that could be somehow taken care for (I thought e.g. about automatic adding of underscores, e.g. _print, but that is not good solution). Well, the thing is, that I am not actually even sure, what am I asking for :-) So, I would like to ask, if some REBOL gurus thought about such topics, or am I completly unrealistic here? Thanks ... |
Geomol 4-Aug-2007 [8605] | Some thoughts: Case 3) is like in object-orientated languages. You inherit words from parent context (object or class) and can use them right away without any further syntax. You'll probably see system/words/word references in cases, where it is words that very like get reused/redefined. So it's typed like that to make sure, it's the system definition of the word, that is being used. I'll give you, it's not the most pretty and easy to read. Maybe some use of BIND can avoid it. |
btiffin 4-Aug-2007 [8606] | Pekr; I'm kinda of kidding, but not. Avoid Multiple Inheritance it a plague :) |
Gabriele 4-Aug-2007 [8607] | Petr, there is no such hierarchy in REBOL. there is no "parent" or "child" context. |
Pekr 4-Aug-2007 [8608x2] | and maybe that is wrong? |
I remember QNX, everything in system was hierarchical, accessible via nodes. As you think of compositing engines, networking, filesystems, - all use hierarchies/trees. I just thought that because REBOL got paths, we could put more thoughts to it and make it an universal aproach :-) | |
Gabriele 4-Aug-2007 [8610x2] | that is not wrong. |
and, changing that would mean making something that is not rebol anymore. | |
btiffin 4-Aug-2007 [8612] | I agree. Relative context is the way to go. (But, always a but), Petr's point about system/words/copy inside the scheme overlays seems a little, hacky? for such core functionality. I'd almost prefer to see the scheme front end code made a little more complex and include a uses block or some such that allows clear mapping from redefined words to 'previous' behaviour. |
Gabriele 5-Aug-2007 [8613x2] | who makes you think that the system/words/copy thing happens in R3 schemes? |
who = what | |
Geomol 5-Aug-2007 [8615] | :-) Nice! |
btiffin 5-Aug-2007 [8616] | I was hoping..., but didn't want to say anything. :) |
Joe 14-Aug-2007 [8617x2] | hi, how do I go about timing out ports opened with direct/no-wait |
thanks | |
Pekr 14-Aug-2007 [8619x2] | what do you mean by timing out? |
when you use direct/no-wait, it does not wait. You have to explicitly call wait to get events. Also copying from port does not block ... | |
sqlab 14-Aug-2007 [8621x2] | Hi Joe something like either port: wait reduce [opened-port1 opened-port2 timeout] [ print "data available" probe copy port ] [ print "timeout" ] |
You can also have a look at dispatch | |
james_nak 15-Aug-2007 [8623] | I was wondering if I am going about searching for particular values wrong. If I have a block of objects and I want to search for a particular value within one of those objects should I go though each obj using something like "foreach" or is there a better way. For example movies: [m1 m2 m2] where m1 is an object with a "title" value, etc. foreach movie movies [ if movie/title == "Star Wars" [.....] ] Of course that works but it seems primitive. |
Brock 15-Aug-2007 [8624x2] | I'd be interested in seeing what others do in this situation as well. I believe most people would be using one of the sql options available to clean this up. |
I know there is a sql dialect out there, it would be interesting to know how it performs this type of query. | |
Gregg 15-Aug-2007 [8626] | Don't confuse "primitive" with "simple and obvious". :-) Without trying to avoid answering your question (what you're doing is fine :-), let me ask some questions in return: What is your goal? Do you want to improve readability? Allow users to enter queries? Improve performance? What goes in the [....] block? What would you have to do to perform this task *without* examining each object? |
james_nak 15-Aug-2007 [8627] | Gregg, well in the back of my mind since I started programming with BASIC, C and Assembler (which, without wanting to start an Altme-war, I refer to as 'procedural' as opposed to OO), I was just wondering if there was another "object-oriented" way. You know, like "find" but with special parameters that tell it to do what my "foreach" actually does. I don't know, it just seemed kind of "Dorky." : ) I'm writing an app that will produce php code to help me administer mysql db's. I'm at the point where it can read the table and field data and create objects with that info. Now I'm at the part where it goes back and pulls that data out. So, I've assigned each table an index # then in the "columns" object, it refers back to that index. Since I have a block of those column objects I was just looking for a spiffy way of finding which ones, for example, of finding all of the objects that are part of table index #3. I've always used the "foreach " method but you know, I'm always looking for a way to improve my code. Thanks Gregg for your input. |
Geomol 15-Aug-2007 [8628] | James, are you after a search three? Do you know those data structures? Examples are binary search threes, B-threes, etc. |
BrianH 15-Aug-2007 [8629] | Do you mean tree? |
Geomol 15-Aug-2007 [8630] | Yes, of course! Tree! Sorry about that. |
james_nak 15-Aug-2007 [8631] | Actually I was just wanting to know if I was missing something in the way I am checking for a value within an object that is part of a block of objects. Nothing really sophisticated and these blocks are really small so no need for speed increases. To be frank, I often look at the code you all write and say to myself: " Self, how in the world did they think of that?" or "Oh, I didn't know you could do that." For example when I first started using Rebol, I didn't know about the "in" word as in "Get in object 'word.." so I was always using paths and trying to figure out how one would make the path a "variable." (object/mypath, where mypath could be some changing value). Thanks for your input though. |
Geomol 15-Aug-2007 [8632x2] | Maybe you could make a block with the titles and the objects together, and then just use a path to get to the object? Something like: >> movies: reduce ["Star Wars" make object! [status: 'good!] "Matrix" make object! [status: 'cool]] >> movies/("Star Wars")/status == good! >> movies/("Matrix")/status == cool |
I'm just throwing ideas! :-) Work with it. | |
james_nak 15-Aug-2007 [8634x2] | You see, stuff like that is very interesting to me. |
I didn't know you could use ( ) like that. | |
Geomol 15-Aug-2007 [8636] | I think, we were allowed to use () in paths in recent versions of REBOL. Not exactly sure when. |
james_nak 15-Aug-2007 [8637] | Why doesn't anyone tell me these things? : ) |
Rebolek 15-Aug-2007 [8638x2] | james_nak: http://www.rebol.com/article/0025.html:) |
it's almost three years...time runs so fast :))) | |
Gregg 16-Aug-2007 [8640] | Another thing to consider is that this is a general need, so FOREACH (e.g.) may be used, but you can hide it in a wrapper func, maybe called SELECT-ALL, that works like REMOVE-EACH. I have different variations, based on how other langs do it, e.g. select/inject in smalltalk. Here's a very quick way to leverage REVMOE-EACH. filter: keep-each: func [ "Keeps only values from a series where body block returns TRUE." 'word [get-word! word! block!] "Word or block of words to set each time (will be local)" series [series!] "Series to traverse" body [block!] "Block to evaluate. Return TRUE to collect." ] [ remove-each :word series join [not] to paren! body ] comment { filter x [1 2 3] [x = 2] filter x [1 2 3] [odd? x] filter res [1 2 3] [odd? res] filter [x y] [a 1 b 2 c 3] [all [odd? y 'c = x]] } |
james_nak 16-Aug-2007 [8641] | Thanks Gregg and Rebolek! |
Joe 17-Aug-2007 [8642] | pekr,sqlab, thank you for your answers. I thought that sync ports also had a timeout like the async kernel (set-modes port [timeout: 30]) but they do not. thanks |
Henrik 20-Aug-2007 [8643x2] | I may be the last to learn this, but I didn't know you could do this: >> type? first [none] == word! >> type? first [#[none]] == none! |
which is neat :-) | |
Geomol 21-Aug-2007 [8645] | Any thoughts on this? >> #"a" * 2 == #"Â" >> 2 * #"a" == 194 So multiply is commutative in a 'funny' way. In this example, you get the result in the same datatype as the first argument. This also works: >> #"a" * 2.0 == #"Â" But you can't do: >> 2.0 * #"a" ** Script Error: Cannot use multiply on decimal! value So multiply is not commutative, when it comes to decimals and chars. Any comments? Also think of other datatypes, you wanna multiply. |
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