[Rd] parse(text=...) and the srcfile attribute

Deepayan Sarkar deepayan.sarkar at gmail.com
Fri Jul 13 04:10:59 CEST 2007


On 7/12/07, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> You can do this:
>
> > foo at srcfile$lines
> [1] "\na <- 1; b <- 2**2\na + b\n"
>
> > # or this
> > as.character(foo)
> [1] "a <- 1"   "b <- 2^2" "a + b"

Neither of which is what I want. I want

> sapply(attr(foo, "srcref"), as.character)
[1] "a <- 1"    "b <- 2**2" "a + b"

but was hoping for a better way than this.

-Deepayan

>
> On 7/12/07, Deepayan Sarkar <deepayan.sarkar at gmail.com> wrote:
> > Hi,
> >
> > I'm trying to understand whether the new source file references can
> > help me with something I want to do. Let's say I have
> >
> > foo <- parse(text = "
> > a <- 1; b <- 2**2
> > a + b
> > ")
> >
> > I now wish to recover the sources for the parsed expressions. I can
> > get them one at a time:
> >
> > > foo[[2]]
> > b <- 2^2
> > > as.character(attr(foo, "srcref")[[2]])
> > [1] "b <- 2**2"
> >
> > Is there a better way? Perhaps like the print method
> >
> > > as.character(foo, useSource = TRUE)
> >
> > could give all the sources at once?
> >
> > -Deepayan
> >
> > ______________________________________________
> > R-devel at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> >
>



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