The R Project SVN R

% File src/library/utils/man/sourceutils.Rd
% Part of the R package, http://www.R-project.org
% Copyright 2011 R Core Development Team
% Distributed under GPL 2 or later

\name{sourceutils}
\alias{getSrcFilename}
\alias{getSrcDirectory}
\alias{getSrcref}
\alias{getSrcLocation}
\title{
Source reference utilities
}
\description{
These functions extract information from source references.
}
\usage{
getSrcFilename(x, full.names = FALSE, unique = TRUE)
getSrcDirectory(x, unique=TRUE) 
getSrcref(x)
getSrcLocation(x, which=c("line", "column", "byte", "parse"), 
                first=TRUE)
}
\arguments{
  \item{x}{
An object (typically a function) containing source references.
}
  \item{full.names}{
Whether to include the full path in the filename result.
}
  \item{unique}{
Whether to list only unique filenames/directories.
}
  \item{which}{
Which part of a source reference to extract.
}
  \item{first}{
Whether to show the first (or last) location of the object.
}
}
\details{
Each statement of a function will have its own source reference if
\code{options(keep.source=TRUE)}.  These functions retrieve all of them.

The components are as follows:
\describe{
\item{line}{The line number where the object starts or ends.}
\item{column}{The column number where the object starts or ends.}
\item{byte}{As for \code{"column"}, but counting bytes, which may differ in case
of multibyte characters.}
\item{parse}{As for \code{"line"}, but this ignores \code{#line} directives.}
}
}
\value{
\code{getSrcFilename} and \code{getSrcDirectory} return character vectors 
holding the filename/directory.

\code{getSrcref} returns a list of \code{"srcref"} objects or \code{NULL} if there are none.

\code{getSrcLocation} returns an integer vector of the requested type of locations
}
\seealso{
\code{\link{srcref}}
}
\examples{
fn <- function(x) {
  x + 1 # A comment, kept as part of the source
}               

# Show the temporary file directory
# where the example was saved

getSrcDirectory(fn)  
getSrcLocation(fn, "line")
}
\keyword{ utilities }