| Line 38... |
Line 38... |
| 38 |
MethodsListSelect(f, env, mlist, fEnv, finalDefault, evalArgs,
|
38 |
MethodsListSelect(f, env, mlist, fEnv, finalDefault, evalArgs,
|
| 39 |
useInherited, fdef, resetAllowed)
|
39 |
useInherited, fdef, resetAllowed)
|
| 40 |
|
40 |
|
| 41 |
}
|
41 |
}
|
| 42 |
\arguments{
|
42 |
\arguments{
|
| 43 |
\item{f}{ The character-string name of the generic function.
|
43 |
\item{f}{The character-string name of the generic function.}
|
| 44 |
|
- |
|
| 45 |
}
|
- |
|
| 46 |
\item{signature}{ The signature of classes to match to the arguments
|
44 |
\item{signature}{the signature of classes to match to the arguments
|
| 47 |
of \code{f}. See the details below.
|
45 |
of \code{f}. See the details below.
|
| 48 |
|
46 |
|
| 49 |
For \code{selectMethod}, the signature can optionally be an
|
47 |
For \code{selectMethod}, the signature can optionally be an
|
| 50 |
environment with classes assigned to the names of the corresponding
|
48 |
environment with classes assigned to the names of the corresponding
|
| 51 |
arguments. Note: the names correspond to the names of the classes, \emph{not}
|
49 |
arguments. Note: the names correspond to the names of the classes, \emph{not}
|
| 52 |
to the objects supplied in a call to the generic function. (You
|
50 |
to the objects supplied in a call to the generic function. (You
|
| 53 |
are not likely to find this approach convenient, but it is used
|
51 |
are not likely to find this approach convenient, but it is used
|
| 54 |
internally and is marginally more efficient.)
|
52 |
internally and is marginally more efficient.)
|
| 55 |
}
|
53 |
}
|
| 56 |
\item{where}{ The position or environment in which to look for the method(s): by default,
|
54 |
\item{where}{The position or environment in which to look for the
|
| 57 |
anywhere in
|
- |
|
| 58 |
the current search list.}
|
55 |
method(s): by default, anywhere in the current search list.}
|
| 59 |
\item{optional}{ If the selection does not produce a unique result,
|
56 |
\item{optional}{ If the selection does not produce a unique result,
|
| 60 |
an error is generated, unless this argument is \code{TRUE}. In that
|
57 |
an error is generated, unless this argument is \code{TRUE}. In that
|
| 61 |
case, the value returned is either a \code{MethodsList} object, if
|
58 |
case, the value returned is either a \code{MethodsList} object, if
|
| 62 |
more than one method matches this signature, or \code{NULL} if no
|
59 |
more than one method matches this signature, or \code{NULL} if no
|
| 63 |
method matches.}
|
60 |
method matches.}
|
| Line 66... |
Line 63... |
| 66 |
generic function. To restrict the search to a particular package
|
63 |
generic function. To restrict the search to a particular package
|
| 67 |
or environment, e.g., supply this argument as
|
64 |
or environment, e.g., supply this argument as
|
| 68 |
\code{getMethodsMetaData(f,where)}. For \code{selectMethod}, see
|
65 |
\code{getMethodsMetaData(f,where)}. For \code{selectMethod}, see
|
| 69 |
the discussion of argument \code{fdef}.
|
66 |
the discussion of argument \code{fdef}.
|
| 70 |
}
|
67 |
}
|
| 71 |
|
- |
|
| 72 |
\item{fdef}{In \code{selectMethod}, the \code{MethodsList} object
|
68 |
\item{fdef}{In \code{selectMethod}, the \code{MethodsList} object
|
| 73 |
and/or the generic function object can be explicitly supplied. (Unlikely to be used, except in the
|
69 |
and/or the generic function object can be explicitly supplied.
|
| - |
|
70 |
(Unlikely to be used, except in the recursive call that finds
|
| 74 |
recursive call that finds matches to more than one argument.)}
|
71 |
matches to more than one argument.)}
|
| 75 |
|
- |
|
| 76 |
\item{env}{The environment in which argument evaluations are done in
|
72 |
\item{env}{The environment in which argument evaluations are done in
|
| 77 |
\code{MethodsListSelect}. Currently must be supplied, but should
|
73 |
\code{MethodsListSelect}. Currently must be supplied, but should
|
| 78 |
usually be \code{sys.frame(sys.parent())} when calling the function
|
74 |
usually be \code{sys.frame(sys.parent())} when calling the function
|
| 79 |
explicitly for debugging purposes.}
|
75 |
explicitly for debugging purposes.}
|
| 80 |
\item{fEnv, finalDefault, evalArgs, useInherited, resetAllowed}{ Internal-use
|
76 |
\item{fEnv, finalDefault, evalArgs, useInherited, resetAllowed}{ Internal-use
|
| Line 154... |
Line 150... |
| 154 |
sense that the evaluator code constructs and executes a call to
|
150 |
sense that the evaluator code constructs and executes a call to
|
| 155 |
\code{MethodsListSelect} when it does not already have a cached method
|
151 |
\code{MethodsListSelect} when it does not already have a cached method
|
| 156 |
for this generic function and signature. (The value returned is
|
152 |
for this generic function and signature. (The value returned is
|
| 157 |
stored by the evaluator so that the search is not required next
|
153 |
stored by the evaluator so that the search is not required next
|
| 158 |
time.)
|
154 |
time.)
|
| 159 |
|
- |
|
| 160 |
|
- |
|
| 161 |
}
|
155 |
}
|
| 162 |
\value{
|
156 |
\value{
|
| 163 |
The call to \code{selectMethod} or \code{getMethod} returns a
|
157 |
The call to \code{selectMethod} or \code{getMethod} returns a
|
| 164 |
\code{\link{MethodDefinition-class}} object, the selected method, if
|
158 |
\code{\link{MethodDefinition-class}} object, the selected method, if
|
| 165 |
a unique selection exists.
|
159 |
a unique selection exists.
|
| Line 189... |
Line 183... |
| 189 |
interface developed more recently than the reference. For a
|
183 |
interface developed more recently than the reference. For a
|
| 190 |
discussion of details and ongoing development, see the web page
|
184 |
discussion of details and ongoing development, see the web page
|
| 191 |
\url{http://developer.r-project.org/methodsPackage.html} and the
|
185 |
\url{http://developer.r-project.org/methodsPackage.html} and the
|
| 192 |
pointers from that page.
|
186 |
pointers from that page.
|
| 193 |
}
|
187 |
}
|
| - |
|
188 |
\seealso{\code{\link{GenericFunctions}}}
|
| 194 |
\examples{
|
189 |
\examples{
|
| 195 |
setGeneric("testFun", function(x)standardGeneric("testFun"))
|
190 |
setGeneric("testFun", function(x)standardGeneric("testFun"))
|
| 196 |
setMethod("testFun", "numeric", function(x)x+1)
|
191 |
setMethod("testFun", "numeric", function(x)x+1)
|
| 197 |
hasMethod("testFun", "numeric")
|
192 |
hasMethod("testFun", "numeric")
|
| 198 |
\dontrun{[1] TRUE}
|
193 |
\dontrun{[1] TRUE}
|
| Line 203... |
Line 198... |
| 203 |
hasMethod("testFun") # default method
|
198 |
hasMethod("testFun") # default method
|
| 204 |
\dontrun{[1] FALSE}
|
199 |
\dontrun{[1] FALSE}
|
| 205 |
hasMethod("testFun", "ANY")
|
200 |
hasMethod("testFun", "ANY")
|
| 206 |
\dontrun{[1] FALSE}
|
201 |
\dontrun{[1] FALSE}
|
| 207 |
\dontshow{
|
202 |
\dontshow{
|
| 208 |
stopifnot(isGeneric("testFun"))
|
203 |
stopifnot(isGeneric("testFun"),
|
| 209 |
stopifnot(hasMethod("testFun", "numeric"))
|
204 |
hasMethod("testFun", "numeric"),
|
| 210 |
stopifnot(hasMethod("testFun", "integer"))
|
205 |
hasMethod("testFun", "integer"),
|
| 211 |
stopifnot(!existsMethod("testFun", "integer"))
|
206 |
!existsMethod("testFun", "integer"),
|
| 212 |
stopifnot(!hasMethod("testFun"))
|
207 |
!hasMethod("testFun"),
|
| 213 |
stopifnot(!hasMethod("testFun", "ANY"))
|
208 |
!hasMethod("testFun", "ANY") )
|
| 214 |
removeGeneric("testFun")
|
209 |
removeGeneric("testFun")
|
| 215 |
}
|
210 |
}
|
| 216 |
}
|
211 |
}
|
| 217 |
\keyword{programming}
|
212 |
\keyword{programming}
|
| 218 |
\keyword{classes}
|
213 |
\keyword{classes}
|
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