Rdo_collect_metadata: Collect aliases or other metadata from an Rd object

Description

Collect aliases or other metadata from an Rd object

Usage

Rdo_collect_aliases(rdo)

Rdo_collect_metadata(rdo, sec)

Arguments

rdo

an Rd object

sec

the kind of metadata to collect, a character string, such as "alias" and "keyword".

Value

a named character vector, as described in details.

Details

Rdo_collect_aliases finds all aliases in rdo and returns them as a named character vector. The name of an alias is usually the empty string, "", but it may also be "windows" or "unix" if the alias is wrapped in a #ifdef directive with the corresponding first argument. Rdo_collect_metadata is a generalisation of the above which collect the metadata from sections sec, where sec is the name of a section without the leading backslash. sec is assumed to be a section containing a single word, such as "keyword", "alias", "name".

Examples

Run this code

# this needs "timezones.Rd".

infile <- file.path(R.home(), "src/library/base/man/timezones.Rd")
rd <- parse_Rd(infile)

# The functions described here handle also "ifdef" and similar
# directives. This contains an element windows = "TZDIR"
Rdo_collect_aliases(rd)

# In contrast, the following do  not find "TZDIR"
sapply(rd[which(tools:::RdTags(rd)=="\alias")], as.character)
tools:::.Rd_get_metadata(rd, "alias")