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base-internal: Internal Objects in Package 'base'

base-internal

R Documentation

Internal Objects in Package base

Description

Internal objects in the base package most of which are only user-visible because of the special nature of the base namespace.

Usage

.subset(x, ...)
.subset2(x, ...)

.getRequiredPackages(file = "DESCRIPTION", lib.loc = NULL,
                     quietly = FALSE, useImports = FALSE)
.getRequiredPackages2(pkgInfo, quietly = FALSE, lib.loc = NULL,
                      useImports = FALSE)



.isMethodsDispatchOn(onOff = NULL)

sys.load.image(name, quiet)
sys.save.image(name)

.row_names_info(x, type = 1L)
.set_row_names(n)

findPackageEnv(info)

lazyLoadDBfetch(key, file, compressed, hook)

.TAOCP1997init(seed)

.gt(x, i, j)
.gtn(x, strictly)

.primTrace(obj)
.primUntrace(obj)

.Date(xx, cl = "Date")
.POSIXct(xx, tz = NULL, cl = c("POSIXct", "POSIXt"))
.POSIXlt(xx, tz = NULL, cl = c("POSIXlt", "POSIXt"))
.difftime(xx, units, cl = "difftime")

.cache_class(class, extends)

.popath

.detach(pos)

.maskedMsg(same, pkg, by)

## Only on Windows:
.fixupGFortranStdout()
.fixupGFortranStderr()

Arguments

`x`	an object for `.subset*()`: from which to extract elements. for `.row_names_info()`: with a `"row.names"` attribute, typically a data frame. for `.gt`, `.gtn`: typically S3- or S4-classed.
`file`	.getRequiredPackages(): The full path to the ‘DESCRIPTION’ file of a package. lazyLoadDBfetch(): the filepath to a lazyload database.
`lib.loc`	a character vector describing the location of R library trees to search through, or `NULL`. The default value of `NULL` corresponds to all libraries currently known to `.libPaths()`.
`quiet`	logical. Should this not give warnings or an error if the package(s) are not found?
`useImports`	logical. Should the `Imports` field be processed?
`quietly`	logical: should message(s) be printed.
`pkginfo`	A processed ‘DESCRIPTION’ file of class `"packageDescription2"`.
`built, run`	platform strings of the form `"cpu-vendor-os"`.
`name`	name of image file to save or load.
`type`	integer. Currently `type = 0` returns the internal `"row.names"` attribute (possibly `NULL`), `type = 2` the number of rows implied by the attribute, and `type = 1` the latter with a negative sign for ‘automatic’ row names.
`n`	integer. The number of rows.
`info`	character string such as `"package:MASS"`.
`key`	the object name in a lazyload database.
`compressed`	logical: are the values in the database compressed?
`refhook`	a load hook: see `unserialize`.
`seed`	a length-one integer vector.
`i, j`	indices.
`strictly`	logical.
`obj`	an R object.
`xx`	a classless object to be placed into the class.
`tz`	an optional time zone.
`cl`	an optional character vector of classes containing the default classes.
`units`	see `difftime`.
`...`	Arguments passed to non-dot name versions.
`pos`	an integer.
`same`	character vector of same objects, masking others.
`pkg`	character string naming the package which is masked from or by.
`by`	logical indicating if the masking happens by `pkg`, or (`by = FALSE`) from `pkg`.

Details

The functions .subset and .subset2 are essentially equivalent to the [ and [[ operators, except that methods dispatch does not take place. This is to avoid expensive unclassing when applying the default method to an object. They should not normally be invoked by end users. Note that unlike the operators they are builtins and not specials (all arguments are evaluated) and hence do not allow missing arguments.

.getRequiredPackages2 attaches all the packages mentioned in the Depends field: failure to find a package is an error. It also checks the versions of the packages found against the Depends field.

.getRequiredPackages is a wrapper to .getRequiredPackages2 using a ‘DESCRIPTION’ file.

The function .isMethodsDispatchOn() returns TRUE if the S4 method dispatch has been turned on in the evaluator (usually by loading package methods). It is meant for R internal use only.

sys.save.image is a system function that is called by q() and its GUI analogs; sys.load.image is called by the startup code. These functions should not be called directly and are subject to change.

sys.save.image closes all connections first, to ensure that it is able to open a connection to save the image. This is appropriate when called from q() and allies, but reinforces the warning that it should not be called directly.

row.names can be stored internally in compact form. .set_row_names(n) generates that form for automatic row names of length n, to be assigned to attr(<a data frame>, "row.names"). .row_names_info gives information on the internal form of the row names for a data frame: for details of what information see the argument type.

.GenericArgsEnv and .ArgsEnv are environments that contain closures with the argument lists that the primitives would have had had they been closures. All the primitives that are internal S3 generics have corresponding members of .GenericArgsEnv and the remaining non-language-element primitives correspond to .ArgsEnv. See the ‘R Internals’ manual for further details. They are used by args and print.default and the QC functions codoc and checkS3methods.

findPackageEnv is invoked by the unserialize code to set a saved environment if possible.

.TAOCP1997init is the initialization code for the "Knuth-TAOCP" RNG.

.gt and .gtn are callbacks from rank and is.unsorted used for (S3 or S4) classed objects.

.primTrace and .primUntrace are the primitive functions underlying trace and untrace respectively.

.Date, .POSIXct, .POSIXlt and .difftime are class generators.

.cache_class caches the inheritance of an S4 class for use in S3 method dispatch. With NULL second argument it returns the cached inheritance, for diagnostic use.

.popath is a variable created at startup which records where the translations package in use is.

.detach is a ‘bare-bones’ version of detach for use in other R packages.

.maskedMsg is a utility called both from attach() and library() for consistency to produce the warning message.

Objects starting .C_ and .F_ are references to registered C and Fortran entry points.

Only on Windows:
.fixupGFortranStdout and .fixupGFortranStderr are helper functions to enable standard output and standard error units in gfortran when executing external code via system and system2. By default, these units are disabled by the Windows profile when running inside RGui.