Get the text of the usage section of Rd documentation.

## Usage

get_usage_text(rdo)

## Arguments

rdo

an Rd object or a character string

## Details

If rdo is a string, it is parsed to obtain an Rd object.

The content of section "\usage" is extracted and converted to string.

a string

## Author

Georgi N. Boshnakov

## Note

todo: get_usage_text can be generalised to any Rd section but it is better to use a different approach since print.Rd() does not take care for some details (escaping %, for example). Also, the functions that use this one assume that it returns R code, which may not be the case if the usage section contains Rd comments.

## Examples

## get the Rd object documenting Rdo_macro
#h <- utils::help("Rdo_macro", lib.loc = .libPaths())
#rdo <- utils:::.getHelpFile(h)
rdo <- Rdo_fetch("Rdo_macro", "Rdpack")
# extract the usage section and print it:
ut <- get_usage_text(rdo)
cat(ut, sep = "\n")
#>
#> Rdo_macro(x, name)
#>
#> Rdo_macro1(x, name)
#>
#> Rdo_macro2(x, y, name)
#>
#> Rdo_item(x, y)
#>
#> Rdo_sigitem(x, y, newline = TRUE)