Re: [R] Singleton pattern
Thanks all of your answers and advices! They brought me some light! I'll have a look to memois package and to tracemem function in order to check if they can help me somehow, at least to understand and trace in detail how memory gets consumed. Thank you all! David 2012/3/16 Jan T. Kim jtt...@googlemail.com Using the singleton pattern in R has never occurred to me so far, as I think it applies to languages that support multiple references to one instance. R doesn't do that, at least not in ways that would be required for applying the singleton pattern as described in the GoF book, anyway. One would have to use closures and / or environments to approximate references, I suppose. When passed around as parameters, R objects don't get copied unless the called function starts modifying them, so if the primary concern is to prevent unnecessary / costly copying of bulky objects, creating the thing once and then passing it around as necessary, taking care that called functions don't change it, is perhaps good enough. Best regards, Jan On Fri, Mar 16, 2012 at 12:15:27PM -0400, Bryan Hanson wrote: Since no one else has bit, I'll take a stab. I'm an experienced R person, but I've recently been teaching myself objective-c and I've been using singletons quite a bit (and mis-using them quite a bit!). Not a computer scientist at all. You've been warned. I don't think there is a comparable concept in R. You do have a choice of S3 or S4 classes for your object orientation in R. S3 is very loose in that you can add to S3 objects readily and abuse them a lot. There really is no checking of them unless you implement it manually. S4 objects are much tighter and they are less readily modified and are self-checking (I know some will complain about this characterization but it's approximately correct). So perhaps you want an S4 object so it's less likely to get mangled, but I doubt there is a way to prevent users from copying it, which would be more along the lines of a singleton. You can google the archives for some great discussions of S3 vs S4 if that sounds interesting. Bryan *** Bryan Hanson Professor of Chemistry Biochemistry DePauw University On Mar 16, 2012, at 7:47 AM, David Cassany wrote: Hi all, I know it may not have much sense thinking about a Singleton Pattern in an R application which doesn't use any OOP facilities, however I'm curious to know if anybody faced the same issue. I've been googling but using singleton pattern as a key word leads to typical OOP languages like Java or C++ among others. So my problem is that I'd like to ensure some very big objects aren't copied again and again in some other variables. In the worst case I'll check all code by myself to ensure it but in this case the application won't force programmers to take it in consideration which is what I am really looking for. Any advice will be highly appreciated :P Thanks! -- *David Cassany Viladomat Software Developer Transmural Biote**ch S.L* [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- +- Jan T. Kim ---+ | email: jtt...@gmail.com| | WWW: http://www.jtkim.dreamhosters.com/ | *-= hierarchical systems are for files, not for humans =-* __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- *David Cassany Viladomat Software Developer Transmural Biote**ch S.L* ** [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] Singleton pattern
Hi all, I know it may not have much sense thinking about a Singleton Pattern in an R application which doesn't use any OOP facilities, however I'm curious to know if anybody faced the same issue. I've been googling but using singleton pattern as a key word leads to typical OOP languages like Java or C++ among others. So my problem is that I'd like to ensure some very big objects aren't copied again and again in some other variables. In the worst case I'll check all code by myself to ensure it but in this case the application won't force programmers to take it in consideration which is what I am really looking for. Any advice will be highly appreciated :P Thanks! -- *David Cassany Viladomat Software Developer Transmural Biote**ch S.L* [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Singleton pattern
Since no one else has bit, I'll take a stab. I'm an experienced R person, but I've recently been teaching myself objective-c and I've been using singletons quite a bit (and mis-using them quite a bit!). Not a computer scientist at all. You've been warned. I don't think there is a comparable concept in R. You do have a choice of S3 or S4 classes for your object orientation in R. S3 is very loose in that you can add to S3 objects readily and abuse them a lot. There really is no checking of them unless you implement it manually. S4 objects are much tighter and they are less readily modified and are self-checking (I know some will complain about this characterization but it's approximately correct). So perhaps you want an S4 object so it's less likely to get mangled, but I doubt there is a way to prevent users from copying it, which would be more along the lines of a singleton. You can google the archives for some great discussions of S3 vs S4 if that sounds interesting. Bryan *** Bryan Hanson Professor of Chemistry Biochemistry DePauw University On Mar 16, 2012, at 7:47 AM, David Cassany wrote: Hi all, I know it may not have much sense thinking about a Singleton Pattern in an R application which doesn't use any OOP facilities, however I'm curious to know if anybody faced the same issue. I've been googling but using singleton pattern as a key word leads to typical OOP languages like Java or C++ among others. So my problem is that I'd like to ensure some very big objects aren't copied again and again in some other variables. In the worst case I'll check all code by myself to ensure it but in this case the application won't force programmers to take it in consideration which is what I am really looking for. Any advice will be highly appreciated :P Thanks! -- *David Cassany Viladomat Software Developer Transmural Biote**ch S.L* [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Singleton pattern
David Cassany david.cassany at transmuralbiotech.com writes: Hi all, I know it may not have much sense thinking about a Singleton Pattern in an R application which doesn't use any OOP facilities, however I'm curious to know if anybody faced the same issue. I've been googling but using singleton pattern as a key word leads to typical OOP languages like Java or C++ among others. While it isn't too hard to implement the Singleton pattern using reference classes, I would think for what you want to do the memoise package can be used. Create a wrapper function to return the objects and the cached value will be returned each time. So my problem is that I'd like to ensure some very big objects aren't copied again and again in some other variables. In the worst case I'll check all code by myself to ensure it but in this case the application won't force programmers to take it in consideration which is what I am really looking for. Any advice will be highly appreciated :P Thanks! __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Singleton pattern
Using the singleton pattern in R has never occurred to me so far, as I think it applies to languages that support multiple references to one instance. R doesn't do that, at least not in ways that would be required for applying the singleton pattern as described in the GoF book, anyway. One would have to use closures and / or environments to approximate references, I suppose. When passed around as parameters, R objects don't get copied unless the called function starts modifying them, so if the primary concern is to prevent unnecessary / costly copying of bulky objects, creating the thing once and then passing it around as necessary, taking care that called functions don't change it, is perhaps good enough. Best regards, Jan On Fri, Mar 16, 2012 at 12:15:27PM -0400, Bryan Hanson wrote: Since no one else has bit, I'll take a stab. I'm an experienced R person, but I've recently been teaching myself objective-c and I've been using singletons quite a bit (and mis-using them quite a bit!). Not a computer scientist at all. You've been warned. I don't think there is a comparable concept in R. You do have a choice of S3 or S4 classes for your object orientation in R. S3 is very loose in that you can add to S3 objects readily and abuse them a lot. There really is no checking of them unless you implement it manually. S4 objects are much tighter and they are less readily modified and are self-checking (I know some will complain about this characterization but it's approximately correct). So perhaps you want an S4 object so it's less likely to get mangled, but I doubt there is a way to prevent users from copying it, which would be more along the lines of a singleton. You can google the archives for some great discussions of S3 vs S4 if that sounds interesting. Bryan *** Bryan Hanson Professor of Chemistry Biochemistry DePauw University On Mar 16, 2012, at 7:47 AM, David Cassany wrote: Hi all, I know it may not have much sense thinking about a Singleton Pattern in an R application which doesn't use any OOP facilities, however I'm curious to know if anybody faced the same issue. I've been googling but using singleton pattern as a key word leads to typical OOP languages like Java or C++ among others. So my problem is that I'd like to ensure some very big objects aren't copied again and again in some other variables. In the worst case I'll check all code by myself to ensure it but in this case the application won't force programmers to take it in consideration which is what I am really looking for. Any advice will be highly appreciated :P Thanks! -- *David Cassany Viladomat Software Developer Transmural Biote**ch S.L* [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- +- Jan T. Kim ---+ | email: jtt...@gmail.com| | WWW: http://www.jtkim.dreamhosters.com/ | *-= hierarchical systems are for files, not for humans =-* __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
