[R] What is a 'closure'?
The R Language Definition at http://cran.r-project.org/doc/manuals/R-lang.html states in the following section 4.3.2 Argument matching This subsection applies to closures but not to primitive functions. What are 'closures'? [[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] What is a 'closure'?
http://www.lemnica.com/esotericR/Introducing-Closures/ Any function you work with will be a closure -- primitives are built-in functions that users can't create. (without source editing recompiling R) E.g. the function c() (type it without parentheses at the prompt to see its code) Let me know if I can explain more, Michael On Thu, Jan 19, 2012 at 2:45 PM, Ajay Askoolum aa2e...@yahoo.co.uk wrote: The R Language Definition at http://cran.r-project.org/doc/manuals/R-lang.html states in the following section 4.3.2 Argument matching This subsection applies to closures but not to primitive functions. What are 'closures'? [[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] What is a 'closure'?
Michael, thank you, especially for the link. I think I understand. The vocabulary is so different! I know 'closure' as 'user-defined function'. [[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] What is a 'closure'?
Ajay Askoolum aa2e72e at yahoo.co.uk writes: Michael, thank you, especially for the link. I think I understand. The vocabulary is so different! I know 'closure' as 'user-defined function'. Not quite. All (??) user-defined functions are closures, but lots of non-user-defined functions are closures too ... typeof(mean) [1] closure typeof(sum) [1] builtin typeof(apply) [1] closure __ 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] What is a 'closure'?
Thanks for clarifying. Is my (new) understanding stated below correct? - A closure is any function (user- or system- defined) where is.primitive(functionName) is FALSE. - is.primitive(functionName) is FALSE when functionName is a system-defined function that is coded in R itself. [[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] What is a 'closure'?
On Jan 19, 2012, at 21:39 , Ben Bolker wrote: Ajay Askoolum aa2e72e at yahoo.co.uk writes: Michael, thank you, especially for the link. I think I understand. The vocabulary is so different! I know 'closure' as 'user-defined function'. Not quite. All (??) user-defined functions are closures, but lots of non-user-defined functions are closures too ... Also, it is not actually the function that is the closure, it is the function completed with its environment, which is where, during evaluation, unbound objects will be sought. The function itself is a parsed version of the function definition. When called, almost all functions will need to find something from their environment, e.g. the - operator. The only functions that are completely self-contained are those that return a constant or one of the function arguments (maybe a few more). -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd@cbs.dk Priv: pda...@gmail.com __ 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] What is a 'closure'?
On Thu, Jan 19, 2012 at 1:15 PM, Ajay Askoolum aa2e...@yahoo.co.uk wrote: Thanks for clarifying. Is my (new) understanding stated below correct? No. -- Bert - A closure is any function (user- or system- defined) where is.primitive(functionName) is FALSE. - is.primitive(functionName) is FALSE when functionName is a system-defined function that is coded in R itself. [[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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm __ 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] What is a 'closure'?
On Thu, Jan 19, 2012 at 1:45 PM, Ajay Askoolum aa2e...@yahoo.co.uk wrote: The R Language Definition at http://cran.r-project.org/doc/manuals/R-lang.html states in the following section 4.3.2 Argument matching This subsection applies to closures but not to primitive functions. What are 'closures'? You might find the discussion here helpful: https://github.com/hadley/devtools/wiki/First-class-functions Hadley -- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ __ 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] What is a 'closure'?
To put a little more concrete example into what Peter and Ben said about the environment being key: environment(c) # NULL This is a primitive, so it has no environment environment(library) # environment: namespace:base Built-in function but it has an environment (usually the namespace of the package whence it comes) But don't think that's only because library() does all its work at the R-level while c() works at the C level environment(as.vector) # Same as above: this function is implemented as an Internal which means (basically) it goes straight to the C level as well # (For completeness sake, it can dispatch as an S3 generic back to R) So the lesson is -- almost anything is a closure except for things that are explicitly primitives. Michael On Thu, Jan 19, 2012 at 4:19 PM, peter dalgaard pda...@gmail.com wrote: On Jan 19, 2012, at 21:39 , Ben Bolker wrote: Ajay Askoolum aa2e72e at yahoo.co.uk writes: Michael, thank you, especially for the link. I think I understand. The vocabulary is so different! I know 'closure' as 'user-defined function'. Not quite. All (??) user-defined functions are closures, but lots of non-user-defined functions are closures too ... Also, it is not actually the function that is the closure, it is the function completed with its environment, which is where, during evaluation, unbound objects will be sought. The function itself is a parsed version of the function definition. When called, almost all functions will need to find something from their environment, e.g. the - operator. The only functions that are completely self-contained are those that return a constant or one of the function arguments (maybe a few more). -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd@cbs.dk Priv: pda...@gmail.com __ 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.
