AFAIK block comment is not possible it needs to be implemented in R interpreter and defined in the parser.'If' solution is not elegant. On 2 September 2017 at 14:09, Uwe Ligges <ligges at statistik.tu-dortmund.de> wrote:> > > On 02.09.2017 11:40, Christian wrote: >> >> I consider it quite worth while to introduce into R syntax a nestable >> block comment like >> >> #{ >> <block of code> >> }# > > > if(FALSE){ > <block of code> > } > > Best, > Uwe Ligges > > >> It would make documentation more easily manageable and lucid. >> Is there considerable need for this. >> >> Please, comment on this. >> How about R core? >> >> Christian > > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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.
Uwe showed an R code -ish way to do it. RStudio and probably other R UI's and IDE's -- which is the way most folks write code, I think -- also make it easy to do. Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Sat, Sep 2, 2017 at 7:54 AM, Suzen, Mehmet <msuzen at gmail.com> wrote:> AFAIK block comment is not possible > it needs to be implemented in R interpreter and defined in the > parser.'If' solution is not elegant. > > On 2 September 2017 at 14:09, Uwe Ligges > <ligges at statistik.tu-dortmund.de> wrote: > > > > > > On 02.09.2017 11:40, Christian wrote: > >> > >> I consider it quite worth while to introduce into R syntax a nestable > >> block comment like > >> > >> #{ > >> <block of code> > >> }# > > > > > > if(FALSE){ > > <block of code> > > } > > > > Best, > > Uwe Ligges > > > > > >> It would make documentation more easily manageable and lucid. > >> Is there considerable need for this. > >> > >> Please, comment on this. > >> How about R core? > >> > >> Christian > > > > > > ______________________________________________ > > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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 at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. >[[alternative HTML version deleted]]
I agree, since one reason for block commenting is to include syntactically-invalid information (such as broken code) in the source code. However, block commenting is not wholly a good thing, as both the R parser and human coders often find it challenging to identify where the end of the block is, making it difficult to tell whether you are looking at live code or comments. A good editor can add/remove comment marks to "blocks" of lines of code, relieving the programmer of tedium while maintaining clarity about which lines are active or not. Block commenting is also a bit of a cultural thing, like using or avoiding tab characters in code, or vi-vs-emacs... it is hard to change people's minds about it, and potentially inflammatory to try. I think it is safe to say that the designers of R were aware of block commenting and consciously chose to not include it in the language. -- Sent from my phone. Please excuse my brevity. On September 2, 2017 7:54:18 AM PDT, "Suzen, Mehmet" <msuzen at gmail.com> wrote:>AFAIK block comment is not possible >it needs to be implemented in R interpreter and defined in the >parser.'If' solution is not elegant. > >On 2 September 2017 at 14:09, Uwe Ligges ><ligges at statistik.tu-dortmund.de> wrote: >> >> >> On 02.09.2017 11:40, Christian wrote: >>> >>> I consider it quite worth while to introduce into R syntax a >nestable >>> block comment like >>> >>> #{ >>> <block of code> >>> }# >> >> >> if(FALSE){ >> <block of code> >> } >> >> Best, >> Uwe Ligges >> >> >>> It would make documentation more easily manageable and lucid. >>> Is there considerable need for this. >>> >>> Please, comment on this. >>> How about R core? >>> >>> Christian >> >> >> ______________________________________________ >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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 at r-project.org mailing list -- To UNSUBSCRIBE and more, see >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.
Is the reason you want a block comment containing code (as opposed to
arbitrary text) that you want to be able to easily run the commented out
code? If so the 'if()' construct has the advantage that you only need
to
change code at the start of the comment, not at both ends.
The if(FALSE) could be if(isTRUE(getOption("DEBUG_ISSUE_XYZ"))) so you
would not even have to change code to re-enable the debugging code, just
call options(DEBUG_ISSUE_XYX=TRUE)).
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Sat, Sep 2, 2017 at 7:54 AM, Suzen, Mehmet <msuzen at gmail.com> wrote:
> AFAIK block comment is not possible
> it needs to be implemented in R interpreter and defined in the
> parser.'If' solution is not elegant.
>
> On 2 September 2017 at 14:09, Uwe Ligges
> <ligges at statistik.tu-dortmund.de> wrote:
> >
> >
> > On 02.09.2017 11:40, Christian wrote:
> >>
> >> I consider it quite worth while to introduce into R syntax a
nestable
> >> block comment like
> >>
> >> #{
> >> <block of code>
> >> }#
> >
> >
> > if(FALSE){
> > <block of code>
> > }
> >
> > Best,
> > Uwe Ligges
> >
> >
> >> It would make documentation more easily manageable and lucid.
> >> Is there considerable need for this.
> >>
> >> Please, comment on this.
> >> How about R core?
> >>
> >> Christian
> >
> >
> > ______________________________________________
> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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 at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>
[[alternative HTML version deleted]]
On 03/09/17 03:56, William Dunlap via R-help wrote:> Is the reason you want a block comment containing code (as opposed to > arbitrary text) that you want to be able to easily run the commented out > code? If so the 'if()' construct has the advantage that you only need to > change code at the start of the comment, not at both ends. > > The if(FALSE) could be if(isTRUE(getOption("DEBUG_ISSUE_XYZ"))) so you > would not even have to change code to re-enable the debugging code, just > call options(DEBUG_ISSUE_XYX=TRUE)).(a) The foregoing is getting too subtle for my feeble brain. (b) A fundamental problem with the if(FALSE) { ... } paradigm is that the enclosed code must be syntactically valid, and there are certainly situations in which one might wish to comment out sections of code that are *not* syntactically valid. E.g. one might wish to comment out *part* of a piece of syntactically valid code for the purpose of experimenting with an alternative approach. cheers, Rolf -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276> On Sat, Sep 2, 2017 at 7:54 AM, Suzen, Mehmet <msuzen at gmail.com> wrote: > >> AFAIK block comment is not possible >> it needs to be implemented in R interpreter and defined in the >> parser.'If' solution is not elegant. >> >> On 2 September 2017 at 14:09, Uwe Ligges >> <ligges at statistik.tu-dortmund.de> wrote: >>> >>> >>> On 02.09.2017 11:40, Christian wrote: >>>> >>>> I consider it quite worth while to introduce into R syntax a nestable >>>> block comment like >>>> >>>> #{ >>>> <block of code> >>>> }# >>> >>> >>> if(FALSE){ >>> <block of code> >>> } >>> >>> Best, >>> Uwe Ligges >>> >>> >>>> It would make documentation more easily manageable and lucid. >>>> Is there considerable need for this. >>>> >>>> Please, comment on this. >>>> How about R core? >>>> >>>> Christian >>> >>> >>> ______________________________________________ >>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >>> 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 at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. >