skeleton.R

#' Create a skeleton for a new package depending on RcppParallel
#' 
#' \code{RcppParallel.package.skeleton} automates the creation of a new source
#' package that intends to use features of RcppParallel.
#' 
#' It is based on the \link[utils]{package.skeleton} function which it executes
#' first.
#' 
#' In addition to \link[Rcpp]{Rcpp.package.skeleton} :
#' 
#' The \samp{DESCRIPTION} file gains an Imports line requesting that the
#' package depends on RcppParallel and a LinkingTo line so that the package
#' finds RcppParallel header files.
#' 
#' The \samp{NAMESPACE} gains a \code{useDynLib} directive as well as an
#' \code{importFrom(RcppParallel, evalCpp} to ensure instantiation of
#' RcppParallel.
#' 
#' The \samp{src} directory is created if it does not exists and a
#' \samp{Makevars} file is added setting the environment variables
#' \samp{PKG_LIBS} to accomodate the necessary flags to link with the
#' RcppParallel library.
#' 
#' If the \code{example_code} argument is set to \code{TRUE}, example files
#' \samp{vector-sum.cpp} is created in the \samp{src} directory.
#' \code{Rcpp::compileAttributes()} is then called to generate
#' \code{src/RcppExports.cpp} and \code{R/RcppExports.R}. These files are given
#' as an example and should eventually by removed from the generated package.
#' 
#' @param name The name of your R package.
#' @param example_code If \code{TRUE}, example C++ code using RcppParallel is
#' added to the package.
#' @param ... Optional arguments passed to \link[Rcpp]{Rcpp.package.skeleton}.
#' @return Nothing, used for its side effects
#' @seealso \link[utils]{package.skeleton}
#' @references Read the \emph{Writing R Extensions} manual for more details.
#' 
#' Once you have created a \emph{source} package you need to install it: see
#' the \emph{R Installation and Administration} manual, \code{\link{INSTALL}}
#' and \code{\link{install.packages}}.
#' @keywords programming
#' @examples
#' 
#' \dontrun{
#' # simple package
#' RcppParallel.package.skeleton("foobar")
#' }
#' 
#' @export RcppParallel.package.skeleton
RcppParallel.package.skeleton<-function(name="anRpackage",
example_code=TRUE,
...)
{
# call Rcpp.package.skeleton() -- provide 'list' explicitly
# and clean up after
env<- new.env(parent= emptyenv())
env$dummy<-NULL
Rcpp::Rcpp.package.skeleton(
name=name,
attributes=FALSE,
module=FALSE,
example_code=FALSE,
environment=env,
list="dummy",
...
 )

# move to generated package directory
owd<- setwd(name)
 on.exit(setwd(owd), add=TRUE)

# remove dummy stuff
 unlink("data", recursive=TRUE)
 unlink("man/dummy.Rd")
 unlink("Read-and-delete-me")
lns<- readLines("NAMESPACE")
 writeLines(lns[!grepl("dummy", lns)], "NAMESPACE")
 unlink("src/init.c")

 message("\nAdding RcppParallel settings")

# update DESCRIPTION file
desc<- read.dcf("DESCRIPTION", all=TRUE, keep.white=TRUE)
version<- sprintf("RcppParallel (>= %s)", utils::packageVersion("RcppParallel"))

desc$Imports<- paste0(desc$Imports, ", ", version)
 message(" >> added Imports: ", desc$Imports)

desc$LinkingTo<- paste0(desc$LinkingTo, ", RcppParallel")
 message(" >> added LinkingTo: ", desc$LinkingTo)

desc$SystemRequirements<-"GNU make"
 message(" >> added SystemRequirements: GNU make")

 write.dcf(desc, file="DESCRIPTION", keep.white=TRUE)

# update NAMESPACE file
 message(" >> added importFrom(RcppParallel,RcppParallelLibs) directive to NAMESPACE")
 cat("importFrom(RcppParallel,RcppParallelLibs)",
file="NAMESPACE",
sep="\n",
append=TRUE)

# write Makevars files
 dir.create("src", showWarnings=FALSE)

# src/Makevars
 message(" >> added src/Makevars")
 cat(
 c(
'# We also need importFrom(RcppParallel,RcppParallelLibs) in NAMESPACE',
'PKG_LIBS += $(shell ${R_HOME}/bin/Rscript -e "RcppParallel::RcppParallelLibs()")'
 ),
file="src/Makevars",
sep="\n"
 )

# src/Makevars.win
 message(" >> added src/Makevars.win")
 cat(
 c(
'PKG_CXXFLAGS += -DRCPP_PARALLEL_USE_TBB=1',
'PKG_LIBS += $(shell "${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" -e "RcppParallel::RcppParallelLibs()")'
 ),
file="src/Makevars.win",
sep="\n"
 )

# write an example script using RcppParallel
if (example_code) {

 message(" >> added example file src/vector-sum.cpp")
 file.copy(
 system.file("skeleton/vector-sum.cpp", package="RcppParallel"),
"src/vector-sum.cpp"
 )

 message(" >> added example documentation man/vector-sum.Rd")
 file.copy(
 system.file("skeleton/vector-sum.Rd", package="RcppParallel"),
"man/vector-sum.Rd"
 )

 message(" >> compiled Rcpp attributes")
Rcpp::compileAttributes()
 }

TRUE
}