| % File src/library/base/man/slotOp.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2017 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{slotOp} |
| \title{Extract or Replace A Slot} |
| \alias{@} |
| \alias{@<-} |
| \description{ |
| Extract or replace the contents of a slot in a object with a |
| formal (S4) class structure. |
| } |
| \usage{ |
| object@name |
| object@name <- value |
| } |
| \arguments{ |
| \item{object}{An object from a formally defined (S4) class.} |
| \item{name}{The character-string name of the slot, quoted or |
| not. Must be the name of a slot in the definition of the class |
| of \code{object}.} |
| \item{value}{A replacement value for the slot, which must be from a |
| class compatible with the class defined for this slot in the |
| definition of the class of \code{object}.} |
| } |
| \details{ |
| These operators support the formal classes of package \pkg{methods}, |
| and are enabled only when package \pkg{methods} is loaded (as per |
| default). See \code{\link{slot}} for further details, in particular |
| for the differences between \code{slot()} and the \code{@} operator. |
| |
| It is checked that \code{object} is an S4 object (see |
| \code{\link{isS4}}), and it is an error to attempt to use \code{@} on |
| any other object. (There is an exception for name \code{.Data} for |
| internal use only.) The replacement operator checks that the slot |
| already exists on the object (which it should if the object is really |
| from the class it claims to be). |
| |
| These are internal generic operators: see \link{InternalMethods}. |
| } |
| \value{ |
| The current contents of the slot. |
| } |
| \seealso{ |
| \code{\link{Extract}}, \code{\link{slot}} |
| } |
| \keyword{manip} |