World: r4wp
[!REBOL3] General discussion about REBOL 3
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Ladislav 20-Jan-2013 [828x6] | , which means I can define my IDENTICAL? function so that identical? 0.0 -0.0 would yield FALSE |
- if you want to see it, read http://www.rebol.net/wiki/Identity | |
That clearly demonstrates that Rebol identity doesn't depend on the behaviour of the SAME? function as much as it seems... | |
It is possible to prove that Rebol identity does not depend on the SAME? function at all, in fact, and unsetting 'same? I obtain the same identity as when the SAME? function is defined. | |
(which is what the article demonstrates, in fact) | |
This actually demonstrates that there may be some level of "arbitrariness" in the implementation of the SAME? function, but if the SAME? function is arbitrary and differs from the IDENTICAL? function then we are able to prove that it is arbitrary and it is not the natural identity existing in Rebol regardless of the SAME? function. | |
GrahamC 20-Jan-2013 [834] | The problem with writing a prot-send.r is that we have no guidance yet on where user variables such as name, email and passwords are to be stored. |
Gregg 20-Jan-2013 [835] | I'll try to read the latest article soon Ladislav, though my scheule is packed right now. Thanks for posting it. |
Ladislav 20-Jan-2013 [836x2] | That is not "the latest article", it is quite old, to be honest. |
You may have just forgotten you already read it | |
Gregg 20-Jan-2013 [838] | I remember if from before, but I thought you updated it. By "latest", though, I meant the most recently referenced here. I still have to finish some others I only read half of. :-) |
BrianH 20-Jan-2013 [839x3] | Graham, put the settings in a structure that is local to the prot-send.r module and managed by it. Non-private module contexts are global. |
Either that or don't have global settings at all, have the settings passed in a structure to the SEND function. Global settings are overrated. | |
Nonetheless, the plan was to have a user preferences system, with preferences persisted to a user-specific data file named user.r, in a declarative dialect (specifically no procedural code allowed in user.r). Unfortunately, that last sentence is as far as the plan got. We were going to have a community discussion about this, but hadn't gotten around to it yet because we're still too early in the development. Maybe now's a good time to start that discussiion. | |
GrahamC 21-Jan-2013 [842x2] | non private global context ? |
non private module contexts are global ? so how to define? | |
BrianH 21-Jan-2013 [844x5] | I apologize if this kind of thing seems complicated, but a lot of the module system happened as side effects of the original design. Carl's original module proposal was high-level and not actually implemented, so there were some implications that he didn't really know about at first. Once we worked through the details, we ended up with a more flexible module system than he originally specified (that was the first rewrite). Then we changed the interface and usage to make it simpler and make the code more maintainable (rewrite two), then refined it based on the new model and added many new ways to make it even simpler to use, and some new features Carl and others wanted (rewrite 3). So I hope that you'll bear with me for a moment. |
Regular modules have names and versions so they can be loaded only once, and upgraded in place if need be. As a side effect, this makes the module's context effectively global. We have a few built-in global contexts, but we don't necessarily have to make built-in global contexts for stuff that is managed by modules because the module contexts are themselves global. | |
The exports of regular modules are collected in the lib context (the "runtime library") when they are initially imported. All potential conflicts between exports of different modules, any overrides that need to be done when you upgrade a module or use another module to make changes, these are all managed in lib. All modules import stuff from lib. You can tell if a module is loaded by checking for it by name, and for that matter even the module system itself can only tell if a module is imported by checking for it by name. | |
Private modules were a side effect of the module name being optional. If a module doesn't have a name, you can't check for whether it is already loaded, so you have to load it again every time it is requested. The module itself can't even tell if it was loaded before, so it can't know whether it needs to resolve conflicts between itself and other instances of itself. That makes it basically unsafe to have an unnamed module export to lib. So instead, we skip the lib middleman and import those exports directly into the target module or user context, which makes the unnamed module effectively owned by that target, a "private" module. We found this facility useful enough that we added an explicit option to make it private (options: [private]). That makes it possible to have a named private module, which has some interesting abilities just from having a name. Having a name means that you can have the module load only once, and being private means that if you want to use its exports you have to import the module explicitly, so combined it means an explicitly accessed module that can share resources with other targets that also explicitly import the same module. | |
Overall, "private" modules are really useful if you are writing traditional modular systems that require explicit importing to manage complexity. This should be familiar to people who have worked with Maxim's slim modules, or Gabriele's module system for R2. The "regular" modules are more useful for writing library code that is intended to be used by people writing scripts, as if R3 were not a modular system. This should make things easier for people coming from R2 or some other non-modular or weak-modular language. Underneath, a "script" is another kind of module; it's just the type of module that does the best job of pretending that it isn't a module. | |
Maxim 21-Jan-2013 [849x5] | one big difference is that slim doesn't bind to a global library area. each module is completely shielded and imports "on its own". its a hierarchical system without namespaces. |
but I'll probably be using modules as the basic construct for slim R3, instead of objects... in my model, it might not really matter, I manage access/biding to/from modules actually altering and expanding the module when it is being loaded. the data being sent to slim isn't executed directly, the block is sent to a manager, which does some binding and security stuff first. | |
it also adds some extra capabilities to all modules, stuff like vprint/vlogging. | |
anyhow... Brian and I will eventually get to actually implementing the R3 module / slim model sometime this year. I don't want to start a philosophical debate here. :-) | |
I mean, I will implement, based on discussions and tests I'll have with Brian, to understand the intricasies of why/how modules are as they are now. | |
Gregg 21-Jan-2013 [854x2] | Brian, is there a doc that has your above comments in it? http://www.rebol.net/wiki/Module_Design_Details looks like it covers a lot of ground, but I don't know if you wrote it, and whether it has some of the design notes included. I think they're very useful and informative. |
And it should have links to Slim and other alternatives. | |
BrianH 21-Jan-2013 [856] | Gregg, I wrote that doc (and forgot the link, thanks), but it needs updating. It is about one or two rewrites behind. |
Gregg 21-Jan-2013 [857] | Hard to keep up, and keep track, with everything. :-) |
BrianH 21-Jan-2013 [858x5] | Maxim, slim modules are like R3's named private isolated modules. And the equivalent of the "global library area" in R2 is system/words, so if you have any code that binds to or imports from system/words then you have the equivalent of lib. |
Btw, module systems like slim are the reason why I changed the underspecified parts of Carl's original module system into features that you might find familiar. It wasn't based on slim specifically, or even Gabriele's system, but an earlier module system that I wrote for the Apache module version of R2 back in 1999. It had similar characteristics to your module systems because I had come from strong modular languages like Oberon and Delphi, and because I had to solve some of the same problems you did. | |
Most of the characteristics of R3's module system are the result of combining the system model of R3, the binding model of Rebol, and Carl's goal of simplifying things for developers not familiar to modular programming. Every bit of syntax that Carl wanted to be optional or minimal in order to make things easier for end-developers had semantic consequences. The runtime library lib, for instance, is the result of having to manage a modular multithreading system that can be used by scripts that can be written as if R3 were single-tasking and monolithic like R2. Doing that requires that modules have certain characteristics (such as a name). | |
Adding the slim management tools won't change the semantic model of R3's modules much, because that semantic model is the result of the system model. However, applications designed to be managed by slim would likely use a different module type by default than applications that are designed around R3's model. Same for porting stuff written for Gabriele's module system, you'd be using the same module type (named private isolated). That's OK, R3's module system supports those models already :) | |
If R3's system model changes, that *would* affect the semantic model of modules. Right now the task! model is a bit underspecified and extremely underimplemented, and the module system is built around Carl's proposed tasking behavior. If that changes, as it might since Carl's proposal isn't fully implemented yet and is incomplete even in spec, then we might have to tweak the semantic model of modules accordingly. | |
Ladislav 21-Jan-2013 [863x2] | News for people interested in decimal molding: >> system/version == 2.101.0.3.1 >> mold 0.1 == "0.1" >> mold 0.3 == "0.3" >> mold 0.30000000000000004 == "0.3" >> mold/all 0.30000000000000004 == "0.30000000000000004" >> mold/all 0.3 == "0.3" >> mold/all 0.1 == "0.1" >> mold/all 0.10000000000000001 == "0.1" >> mold/all 0.10000000000000002 == "0.10000000000000002" >> system/version == 2.101.0.3.1 >> mold/all 0.10000000000000001 == "0.1" >> mold/all 0.10000000000000002 == "0.10000000000000002" >> mold/all 0.3 == "0.3" >> mold/all 0.30000000000000004 == "0.30000000000000004" |
And, BTW, Andreas, regarding the 15 vs 17 digits: I think that we can give in easily in this case, just put system/options/decimal-digits: 17 to your rebol.r and MOLD decimal will behave exactly like MOLD/ALL decimal. | |
GrahamC 21-Jan-2013 [865] | In R2 I have this >> any-string? read/binary %test-module.r == true In R3 >> any-string? read %test-module.r == false |
Andreas 21-Jan-2013 [866] | Yes, Graham, in R3 a binary! is not an any-string!: >> any-string! == make typeset! [string! file! email! url! tag!] |
GrahamC 21-Jan-2013 [867x2] | Why? |
the change? | |
Andreas 21-Jan-2013 [869x2] | I'd assume because only Unicode datatypes are considered any-string! now. |
Ladislav: looks great! | |
Gregg 21-Jan-2013 [871] | Thanks for posting that Ladislav! Keep up the good work. |
GrahamC 21-Jan-2013 [872x2] | https://github.com/gchiu/Rebol3/blob/master/protocols/prot-send.r and with the latest prot-smtp.r can now send attachments .. I tried a 60Mb one and it went fine. same syntax as in R2 send/attach [carl-:-rebol-:-com] "Carl, need to remove the spam from blog comments" %attachment.exe |
Lost text = I send a 60Mb avi as an attachment which went through | |
Oldes 23-Jan-2013 [874x2] | Graham, I'm really not sure it's good idea to show these commands on web-public forum. Why don't you use your email in such a cases? |
Regarding binary not a string - string is unicode which may differ per platforms. | |
GrahamC 23-Jan-2013 [876] | Oldes, I believe emails are scrubbed by the script that uploads these feeds to the rebol.org site |
Bo 23-Jan-2013 [877] | And [carl-:-rebol-:-com] is not Carl's email address any longer. :-) |
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