getPackageName            package:methods            R Documentation

The Name associated with a Given Package

Description:

     The functions below produce the package associated with a
     particular environment or position on the search list, or of the
     package containing a particular function.  They are primarily used
     to support computations that need to differentiate objects on
     multiple packages.

Usage:

     getPackageName(where, create = TRUE)
     setPackageName(pkg, env)

     packageSlot(object)
     packageSlot(object) <- value

Arguments:

   where: the environment or position on the search list associated
          with the desired package.

  object: object providing a character string name, plus the package in
          which this object is to be found.

   value: the name of the package.

  create: flag, should a package name be created if none can be
          inferred?  If 'TRUE' and no non-empty package name is found,
          the current date and time are used as a package name, and a
          warning is issued. The created name is stored in the
          environment if that environment is not locked.

pkg, env: make the string in 'pkg' the internal package name for all
          computations that set class and method definitions in
          environment 'env'.

Details:

     Package names are normally installed during loading of the
     package, by the INSTALL script or by the 'library' function. 
     (Currently, the name is stored as the object '.packageName' but
     don't trust this for the future.)

Value:

     'packageName' returns the character-string name of the package
     (without the extraneous '"package:"' found in the search list).

     'packageSlot' returns or sets the package name slot (currently an
     attribute, not a formal slot, but this may change someday).

     'setPackageName' can be used to establish a package name in an
     environment that would otherwise not have one.  This allows you to
     create classes and/or methods in an arbitrary environment, but it
     is usually preferable to create packages by the standard R
     programming tools ('package.skeleton', etc.)

See Also:

     'search'

Examples:

     ## all the following usually return "base"
     getPackageName(length(search()))
     getPackageName(baseenv())
     getPackageName(asNamespace("base"))
     getPackageName("package:base")

