Rdpack (version 2.6.4)

get_sig_text: Produce the textual form of the signatures of available methods for an S4 generic function require(Rdpack)

Description

Produce the textual form of the signatures of available methods for an S4 generic function.

Usage

get_sig_text(rdo, package = NULL)

Value

A character vector with one element for each method.

Arguments

rdo

an Rd object.

package

if of class "character", give only methods defined by package, otherwise give all methods.

Author

Georgi N. Boshnakov

Details

Signatures are found using function findMethodSignatures from package "methods".

Here we find all methods for show() defined in package "methods" and print the first few of them: .Rdpack.e <- environment();Rdpack:::run_examples(quote({fn <- utils::help("show-methods", package = "methods"); rdo <- utils:::.getHelpFile(fn); head(get_sig_text(rdo))}), local = .Rdpack.e, Rdsection = "preformatted")

Examples

## load another package with some S4 methods ("methods" is already loaded)
require("stats4") 

rdo <- Rdo_fetch("show", package = "methods")
## alternatively:
#fn <- help("show-methods", package = "methods")
#rdo <- utils:::.getHelpFile(fn)

## this will find all methods for "show" in currently loaded packages
## (print only some of them)
head(get_sig_text(rdo))

## this will select only the ones from package "stats4"
get_sig_text(rdo, package = "stats4")

## this is also fine (interactively) but need to choose
## the appropriate element of "fn" if length(fn) > 1
#fn <- help("show-methods")

## this finds nothing
#fn <- help("logLik-methods", package = "methods")
#fn
Rdo_fetch("logLik-methods", package = "methods")

## this does
#fn <- help("logLik-methods", package = "stats4")
#rdo <- utils:::.getHelpFile(fn)
rdo2 <- Rdo_fetch("logLik-methods", package = "stats4")

get_sig_text(rdo2)
get_sig_text(rdo2, package = "stats4")

## only default method defined
## using this:
setGeneric("f1", function(x, y){NULL})
## since the following gives error in pkgdown:
#f1 <- function(x, y){NULL}
#setGeneric("f1")

fn <- tempfile()

reprompt("f1", filename = fn)
rdo <- tools::parse_Rd(fn)
get_sig_text(rdo)

setClass("aRdpack")
setClass("bRdpack")

## several methods defined
setGeneric("f4", function(x, y){NULL})
setMethod("f4", c("numeric", "numeric"), function(x, y){NULL})
setMethod("f4", c("aRdpack", "numeric"), function(x, y){NULL})
setMethod("f4", c("bRdpack", "numeric"), function(x, y){NULL})
setMethod("f4", c("aRdpack", "bRdpack"), function(x, y){NULL})

reprompt("f4", filename = fn)
rdo <- tools::parse_Rd(fn)
get_sig_text(rdo)

unlink(fn)