mirror of
https://github.com/ralsina/tartrazine.git
synced 2024-11-13 23:12:24 +00:00
72 lines
2.6 KiB
Plaintext
72 lines
2.6 KiB
Plaintext
|
% Generated by roxygen2: do not edit by hand
|
|||
|
|
% Please edit documentation in R/hello.R
|
|||
|
|
\name{import}
|
|||
|
|
\alias{import}
|
|||
|
|
\title{Import a module into the current scope}
|
|||
|
|
\usage{
|
|||
|
|
import(module, attach, attach_operators = TRUE)
|
|||
|
|
}
|
|||
|
|
\arguments{
|
|||
|
|
\item{module}{an identifier specifying the full module path}
|
|||
|
|
|
|||
|
|
\item{attach}{if \code{TRUE}, attach the newly loaded module to the object
|
|||
|
|
search path (see \code{Details})}
|
|||
|
|
|
|||
|
|
\item{attach_operators}{if \code{TRUE}, attach operators of module to the
|
|||
|
|
object search path, even if \code{attach} is \code{FALSE}}
|
|||
|
|
}
|
|||
|
|
\value{
|
|||
|
|
the loaded module environment (invisible)
|
|||
|
|
}
|
|||
|
|
\description{
|
|||
|
|
\code{module = import('module')} imports a specified module and makes its
|
|||
|
|
code available via the environment-like object it returns.
|
|||
|
|
}
|
|||
|
|
\details{
|
|||
|
|
Modules are loaded in an isolated environment which is returned, and
|
|||
|
|
optionally attached to the object search path of the current scope (if
|
|||
|
|
argument \code{attach} is \code{TRUE}).
|
|||
|
|
\code{attach} defaults to \code{FALSE}. However, in interactive code it is
|
|||
|
|
often helpful to attach packages by default. Therefore, in interactive code
|
|||
|
|
invoked directly from the terminal only (i.e. not within modules),
|
|||
|
|
\code{attach} defaults to the value of \code{options('import.attach')}, which
|
|||
|
|
can be set to \code{TRUE} or \code{FALSE} depending on the user’s preference.
|
|||
|
|
|
|||
|
|
\code{attach_operators} causes \emph{operators} to be attached by default,
|
|||
|
|
because operators can only be invoked in R if they re found in the search
|
|||
|
|
path. Not attaching them therefore drastically limits a module’s usefulness.
|
|||
|
|
|
|||
|
|
Modules are searched in the module search path \code{options('import.path')}.
|
|||
|
|
This is a vector of paths to consider, from the highest to the lowest
|
|||
|
|
priority. The current directory is \emph{always} considered first. That is,
|
|||
|
|
if a file \code{a.r} exists both in the current directory and in a module
|
|||
|
|
search path, the local file \code{./a.r} will be loaded.
|
|||
|
|
|
|||
|
|
Module names can be fully qualified to refer to nested paths. See
|
|||
|
|
\code{Examples}.
|
|||
|
|
}
|
|||
|
|
\note{
|
|||
|
|
Unlike for packages, attaching happens \emph{locally}: if
|
|||
|
|
\code{import} is executed in the global environment, the effect is the same.
|
|||
|
|
Otherwise, the imported module is inserted as the parent of the current
|
|||
|
|
\code{environment()}. When used (globally) \emph{inside} a module, the newly
|
|||
|
|
imported module is only available inside the module’s search path, not
|
|||
|
|
outside it (nor in other modules which might be loaded).
|
|||
|
|
}
|
|||
|
|
\examples{
|
|||
|
|
# `a.r` is a file in the local directory containing a function `f`.
|
|||
|
|
a = import('a')
|
|||
|
|
a$f()
|
|||
|
|
|
|||
|
|
# b/c.r is a file in path `b`, containing a function `g`.
|
|||
|
|
import('b/c', attach = TRUE)
|
|||
|
|
g() # No module name qualification necessary
|
|||
|
|
|
|||
|
|
}
|
|||
|
|
\seealso{
|
|||
|
|
\code{unload}
|
|||
|
|
|
|||
|
|
\code{reload}
|
|||
|
|
|
|||
|
|
\code{module_name}
|
|||
|
|
}
|