deparse_usage {Rdpack} | R Documentation |
Converts f_usage objects to text appropriate for usage sections in Rd files. Handles S3 methods.
deparse_usage(x) deparse_usage1(x, width = 72) ## S3 method for class 'f_usage' as.character(x, ... )
x |
an object from class |
width |
maximal width of text on a line. |
... |
ignored. |
Both, deparse_usage1
and the as.character
method for
class "f_usage"
, convert an "f_usage"
object to a
character string suitable for Rd documentation. The
as.character
method is the user level function (it just calls
deparse_usage1
), deparse_usage1
is internal function for
programming. In the example below the first command creates an
"f_usage"
object, then the second converts it to character string.
(a <- pairlist2f_usage1(formals(cor), "cor")) ##: name = cor ##: S3class = ##: S4sig = ##: infix = FALSE ##: fu = TRUE ##: argnames = x y use method ##: defaults : y = NULL ##: use = "everything" ##: method = c("pearson", "kendall", "spearman") cat(as.character(a)) ##: cor(x, y = NULL, use = "everything", ##: method = c("pearson", "kendall", "spearman"))
Each usage entriy is formatted and, if necessary, split over several
lines. The width (number of characters) on a line can be changed with
argument width
.
deparse_usage
can be used when x
is a list of
"f_usage"
objects. It calls deparse_usage1
with each of
them and returns a character vector with one element for each
component of x
. When x
is an object from class
"f_usage"
, deparse_usage
is equivalent to
deparse_usage1
.
For deparse_usage1
and as.character.f_usage
, a named
character vector of length one (the name is the function name).
For deparse_usage
, a named character vector with one entry for
the usage text for each function.
Georgi N. Boshnakov
cur_wd <- getwd() tmpdir <- tempdir() setwd(tmpdir) ## prepare a list of "f_usage" objects fnseq <- reprompt(seq) # get and save the help page of "seq" rdoseq <- tools::parse_Rd(fnseq) # parse the Rd file ut <- get_usage_text(rdoseq) # get the contents of the usage section cat(ut, "\n") # of seq() (a character string) utp <- parse_usage_text(ut) # parse to a list of "f_usage" objects ## deparse the "f_usage" list - each statement gets a separate string cat(deparse_usage(utp), sep = "\n") ## explore some of the usage entries individually; ## the generic seq() has a boring signature utp[[1]] as.character(utp[[1]]) deparse_usage1(utp[[1]]) # same ## the default S3 method is more interesting utp[[2]] cat(deparse_usage1(utp[[2]])) cat(as.character(utp[[2]])) # same unlink(fnseq) setwd(cur_wd) unlink(tmpdir)