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\name{DelayedOp-class}
% DelayedOp objects
\alias{class:DelayedOp}
\alias{DelayedOp-class}
\alias{DelayedOp}
\alias{is_noop}
\alias{summary.DelayedOp}
\alias{summary,DelayedOp-method}
% DelayedUnaryOp objects
\alias{class:DelayedUnaryOp}
\alias{DelayedUnaryOp-class}
\alias{DelayedUnaryOp}
% DelayedUnaryIsoOp objects
\alias{class:DelayedUnaryIsoOp}
\alias{DelayedUnaryIsoOp-class}
\alias{DelayedUnaryIsoOp}
\alias{dim,DelayedUnaryIsoOp-method}
\alias{dimnames,DelayedUnaryIsoOp-method}
\alias{extract_array,DelayedUnaryIsoOp-method}
\alias{is_sparse,DelayedUnaryIsoOp-method}
\alias{extract_sparse_array,DelayedUnaryIsoOp-method}
\alias{OLD_extract_sparse_array,DelayedUnaryIsoOp-method}
% DelayedNaryOp objects
\alias{class:DelayedNaryOp}
\alias{DelayedNaryOp-class}
\alias{DelayedNaryOp}
% updateObject()
\alias{updateObject,DelayedOp-method}
\title{DelayedOp objects}
\description{
NOTE: This man page is about \link{DelayedArray} internals and is provided
for developers and advanced users only.
In a \link{DelayedArray} object, the delayed operations are stored as a
tree where the leaves are operands and the nodes are the operations.
Each node in the tree is a DelayedOp derivative representing a particular
delayed operation.
DelayedOp is a virtual class with 8 concrete subclasses. Each subclass
provides a formal representation for a particular kind of delayed
operation.
}
\usage{
is_noop(x)
}
\arguments{
\item{x}{
A DelayedSubset, DelayedAperm, or DelayedSetDimnames object.
}
}
\details{
8 types of nodes are currently supported. Each type is a DelayedOp subclass:
\preformatted{ Node type Represented operation
------------------------------------------------------------------
DelayedOp (VIRTUAL)
------------------------------------------------------------------
* DelayedUnaryOp (VIRTUAL)
o DelayedSubset Multi-dimensional single bracket
subsetting.
o DelayedAperm Extended aperm() (can drop and/or
add ineffective dimensions).
o DelayedUnaryIsoOp (VIRTUAL) Unary op that preserves the
geometry.
- DelayedUnaryIsoOpStack Simple ops stacked together.
- DelayedUnaryIsoOpWithArgs One op with vector-like arguments
along the dimensions of the input.
- DelayedSubassign Multi-dimensional single bracket
subassignment.
- DelayedSetDimnames Set/replace the dimnames.
------------------------------------------------------------------
* DelayedNaryOp (VIRTUAL)
o DelayedNaryIsoOp N-ary op that preserves the
geometry.
o DelayedAbind abind()
------------------------------------------------------------------
}
All DelayedOp objects must comply with the \emph{seed contract} i.e. they
must support \code{dim()}, \code{dimnames()}, and \code{extract_array()}.
See \code{?\link[S4Arrays]{extract_array}} in the \pkg{S4Arrays} package
for more information about the \emph{seed contract}.
This makes them de facto array-like objects. However, end users will never
interact with them directly, except for the root of the tree which is the
DelayedArray object itself and the only node in the tree that they are able
to see and touch.
\code{is_noop()} can only be called on a DelayedSubset, DelayedAperm,
or DelayedSetDimnames object at the moment, and will return \code{TRUE}
if the object represents a no-op.
}
\note{
The DelayedOp virtual class and its 8 concrete subclasses are used inside
a \link{DelayedArray} object to represent delayed operations carried by
the object. They're never exposed to the end user and are not intended to
be manipulated directly.
}
\seealso{
\itemize{
\item DelayedOp concrete subclasses: \link{DelayedSubset},
\link{DelayedAperm}, \link{DelayedUnaryIsoOpStack},
\link{DelayedUnaryIsoOpWithArgs}, \link{DelayedSubassign},
\link{DelayedSetDimnames}, \link{DelayedNaryIsoOp},
and \link{DelayedAbind}.
\item \link{DelayedArray} objects.
\item \code{\link{showtree}} to visualize the nodes and access the
leaves in the tree of delayed operations carried by a
\link{DelayedArray} object.
\item \code{\link{simplify}} to simplify the tree of delayed
operations carried by a \link{DelayedArray} object.
\item \code{\link[S4Arrays]{extract_array}} in the \pkg{S4Arrays} package.
}
}
\keyword{methods}
|
