The R Project SVN – R – Diff – /trunk/src/library/methods/man/setClass.Rd

 \description{
   Functions to create (\code{setClass}) and manipulate class definitions.
+}
 \usage{
 setClass(Class, representation, prototype, contains=character(),
-         validity, access, where=1, version=FALSE, sealed, package)
+         validity, access, where, version, sealed, package)
 removeClass(Class, where)
 isClass(Class, formal=TRUE, where)
     data for the slots specified in the representation. }
   \item{contains}{ what classes does this class extend?  (These are
     called \emph{superclasses} in some languages.)  When these classes
     have slots, all their slots will be contained in the new class as
     well. }
-  \item{where}{ For \code{setClass}, what environment to use to store or remove the
+  \item{where}{ For \code{setClass} and \code{removeClass}, the
+    environment in which to store or remove the
-    definition (as metadata).  Defaults to the top-level environment,
+    definition.  Defaults to the top-level environment of the calling function
-    the global environment for ordinary computations, but the
+    (the global environment for ordinary computations, but the
-    environment or namespace of a package when loading that package.
+    environment or namespace of a package when loading that package).
     For other functions, \code{where} defines where to do the search
-    for the class definition, and the default is to search the visible
+    for the class definition, and the default is to search from the top-level
-    environments or namespace.
+    environment or namespace of the caller to this function.
+    }
   \item{unique}{if \code{findClass} expects a unique location for the
     class, \code{unique} is a character string explaining the purpose
     of the search (and is used in warning and error messages).  By
     default, multiple locations are possible and the function always
   \item{inherits}{in a call to \code{getClasses}, should the value
     returned include all parent environments of \code{where}, or that
     environment only?  Defaults to \code{TRUE} if \code{where} is
     omitted, and to \code{FALSE} otherwise.
+    }
-  \item{validity, access, version}{ Control arguments included for
+  \item{validity}{ if supplied, should be a validity-checking method
+  for objects from this class (a function that returns \code{TRUE} if
+  its argument is a valid object of this class and one or more strings
+  describing the failures otherwise).  See \code{\link{validObject}}
+  for details.  }
+\item{access}{Access list for the class.  Saved in the definition, but
+  not currently used.}
+\item{version}{A version indicator for this definition. Saved in the
-    compatibility with the S-Plus API, but not currently used.  }
+    definition, but not currently used.}
   \item{sealed}{ If \code{TRUE}, the class definition will be sealed,
     so that another call to \code{setClass} will fail on this class name.
+    }
   \item{package}{ An optional package name for the class.  By default
   (and usually) the package where the class definition is assigned
       slots), and methods may be defined including the class name in the
       signature (see \code{\link{setMethod}}).
+    }
     \item{\code{removeClass}:}{
-      Remove the definition of this class.  Calling this \emph{always}
+      Remove the definition of this class, from the environment
-      resets the version of the class cached for the session.  If
+      \code{where} if this argument is supplied; if not,
-      \code{where=0}, that's all it does.  Otherwise, it removes the
+      \code{removeClass} will search for a definition, starting in the
-      version from the specified environment or database (from the global
+      top-level environment of the call to \code{removeClass}, and
-      environment by default).
+      remove the (first) definition found.
+    }
     \item{\code{isClass}:}{
       Is this a the name of a formally defined class? (Argument
-      \code{formal} is for compatibility and is ignored.)  Argument
+      \code{formal} is for compatibility and is ignored.)
-      \code{where} is the environment from which to start the search
-      for the class definition.  By default, start at the global
-      environment and search through the search list.
+    }
     \item{\code{getClasses}:}{
       The names of all the classes formally defined on \code{where}.  If
     \item{\code{findClass}:}{
         The list of environments or positions on the search list in
         which a class definition of \code{Class} is found.  If
         \code{where} is supplied, this is an environment (or
         namespace) from which the search takes place; otherwise the
-        top-level environment is used.  If \code{unique} is supplied
+        top-level environment of the caller is used.  If \code{unique} is supplied
         as a character string, \code{findClass} returns a single
         environment or position.  By default, it always returns a
-        list.
-        In the second case, the calling function should select, say, the first element
+        list.  The calling function should select, say, the first element
         as a position or environment for functions such as
+        \code{\link{get}}.
-        \code{\link{get}}. In the first case, \code{findClass} will
+        If \code{unique} is supplied as a character string, \code{findClass} will
         warn if there is more than one definition visible (using the
-        string supplied as \code{unique} to identify the purpose of
+        string to identify the purpose of
         the call), and will generate an error if no definition can be found.
+    }
-    \item{\code{unclass}:}{
-      Returns the object containing the values of all the slots in this
-      object's class definition (specifically, if the returned object
-      has attributes corresponding to each slot), in the case that the
-      object's class is formally defined with slots.  For classes that
-      extend a single other class (e.g., a basic class such as
-      \code{"numeric"}) the result is an object of that class.
-    }
     \item{\code{resetClass}:}{
       Reset the internal definition of a class.  Causes the complete
       definition of the class to be re-computed, from the
       representation and superclasses specified in the original

The R Project SVN R

(root)/trunk/src/library/methods/man/setClass.Rd – Rev 26000 → 26365