From: Gabor Grothendieck <ggrothendieck_at_gmail.com>

Date: Mon, 09 Jul 2007 14:58:11 -0400

> > (function(x,...) "{"(x,...))(1,2)

*> Error in (function(x, ...) { : '...' used in an incorrect context
*

> Not sure exactly why this is so, but "{" has somewhat nonstandard

*> evaluation semantics and you cannot do
*

*> "{x, ...}" either, nor for that matter x <- function(...)...; x(2),
*

*> which gives off a similar error.
*

*> > https://stat.ethz.ch/mailman/listinfo/r-devel
*

*> >
*

Date: Mon, 09 Jul 2007 14:58:11 -0400

Just one additional observation. { does work with mapply:

> f <- function(x, y) y

> mapply(f, letters, 1:26)

a b c d e f g h i j k l m n o p q r s t u v w x y z
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

> mapply("{", letters, 1:26) # same

a b c d e f g h i j k l m n o p q r s t u v w x y z
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

On 7/9/07, Peter Dalgaard <P.Dalgaard_at_biostat.ku.dk> wrote:

> Gabor Grothendieck wrote:

*> > Why does the error get generated here? Is it a bug? It seems that
**> > f and "{" are the same but when used in sapply f works but { does not.
**> > Is its use in lapply really "an incorrect context"?
**> >
**> >
**> >> f <- function(x, y) y
**> >> f(1, 2)
**> >>
**> > [1] 2
**> >
**> >> "{"(1, 2)
**> >>
**> > [1] 2
**> >
**> >> lapply("y", function(x, y) y, 1:4) # ok
**> >>
**> > [[1]]
**> > [1] 1 2 3 4
**> >
**> >> lapply("y", "{", 1:4) # error
**> >>
**> > Error in lapply("y", "{", 1:4) : '...' used in an incorrect context
**> >
**> lapply() is not really part of the problem:
*

>

> > (function(x,...) "{"(x,...))(1,2)

>

> Not sure exactly why this is so, but "{" has somewhat nonstandard

> >

> >> R.version.string # XP

> >>> > [1] "R version 2.5.1 (2007-06-27)"> >> > See:> >> > https://www.stat.math.ethz.ch/pipermail/r-help/2007-July/135999.html> >> > for a variation of the lapply using sapply (which also has the same> > problem if one uses { instead of f).> >> > ______________________________________________> > R-devel_at_r-project.org mailing list

> >Received on Mon 09 Jul 2007 - 19:00:35 GMT

> --

> O__ ---- Peter Dalgaard ุster Farimagsgade 5, Entr.B

> c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K> (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918> ~~~~~~~~~~ - (p.dalgaard_at_biostat.ku.dk) FAX: (+45) 35327907

> > > ______________________________________________ R-devel_at_r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel

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