Rd Converters

Description

These functions take the output of parse_Rd(), an Rd object, and produce a help page from it. As they are mainly intended for internal use, their interfaces are subject to change.

Usage

Rd2HTML(Rd, out = "", package = "", defines = .Platform$OS.type,
        Links = NULL, Links2 = NULL,
        stages = "render", outputEncoding = "UTF-8",
        dynamic = FALSE, no_links = FALSE, fragment = FALSE,
        stylesheet = if (dynamic) "/doc/html/R.css" else "R.css",
        texmath = getOption("help.htmlmath"),
        concordance = FALSE,
        standalone = TRUE,
        hooks = list(),
        toc = isTRUE(getOption("help.htmltoc")),
        Rhtml = FALSE,
        ...)

Rd2txt(Rd, out = "", package = "", defines = .Platform$OS.type,
       stages = "render", outputEncoding = "",
       fragment = FALSE, options, ...)

Rd2latex(Rd, out = "", defines = .Platform$OS.type,
         stages = "render", outputEncoding = "UTF-8",
         fragment = FALSE, ..., writeEncoding = TRUE,
         concordance = FALSE)

Rd2ex(Rd, out = "", defines = .Platform$OS.type,
      stages = "render", outputEncoding = "UTF-8",
      commentDontrun = TRUE, commentDonttest = FALSE, ...)

Arguments

Details

These functions convert help documents: Rd2HTML produces HTML, Rd2txt produces plain text, Rd2latex produces LaTeX. Rd2ex extracts the examples in the format used by example and R utilities.

Each of the functions accepts a filename for an Rd file, and will use parse_Rd to parse it before applying the conversions or checks.

The difference between arguments Link and Link2 is that links are looked in them in turn, so lazy-evaluation can be used to only do a second-level search for links if required.

Before R 3.6.0, the default for Rd2latex was outputEncoding = "ASCII", including using the second option of ⁠\enc⁠ markup, because LaTeX versions did not provide enough coverage of UTF-8 glyphs for a long time.

Rd2txt will format text paragraphs to a width determined by width, with appropriate margins. The default is to be close to the rendering in versions of R < 2.10.0.

Rd2txt will use directional quotes (see sQuote) if option "useFancyQuotes" is true (usually the default, see sQuote) and the current encoding is UTF-8.

Various aspects of formatting by Rd2txt are controlled by the options argument, documented with the Rd2txt_options function. Changes made using options are temporary, those made with Rd2txt_options are persistent.

When fragment = TRUE, the Rd file will be rendered with no processing of ⁠\Sexpr⁠ elements or conditional defines using ⁠#ifdef⁠ or ⁠#ifndef⁠. Normally a fragment represents text within a section, but if the first element of the fragment is a section macro, the whole fragment will be rendered as a series of sections, without the usual sorting.

Value

These functions are executed mainly for the side effect of writing the converted help page. Their value is the name of the output file (invisibly). For Rd2latex, the output name is given an attribute "latexEncoding" giving the encoding of the file in a form suitable for use with the LaTeX ‘⁠inputenc⁠’ package. For Rd2HTML with standalone = FALSE, an attribute "info" gives supplementary information such as the contents of the name and title fields. This is currently experimental, and the details are subject to change.

For Rd2HTML and Rd2latex with concordance = TRUE, a "concordance" attribute is added, containing an Rconcordance object.

Encodings

Rd files are normally intended to be rendered on a wide variety of systems, so care must be taken in the encoding of non-ASCII characters. In general, any such encoding should be declared using the ‘⁠encoding⁠’ section for there to be any hope of correct rendering.

For output, the outputEncoding argument will be used: outputEncoding = "" will choose the native encoding for the current system.

If the text cannot be converted to the outputEncoding, byte substitution will be used (see iconv): Rd2latex and Rd2ex give a warning.

Note

The ⁠\Sexpr⁠ macro includes R code that will be executed at one of three times: build time (when a package's source code is built into a tarball), install time (when the package is installed or built into a binary package), and render time (when the man page is converted to a readable format).

For example, this man page was:

1. built on 2024-07-31 at 04:36:18,

2. installed on 2024-07-31 at 04:36:18, and

3. rendered on 2024-07-31 at 04:36:38.

Author(s)

Duncan Murdoch, Brian Ripley

References

https://developer.r-project.org/parseRd.pdf

See Also

parse_Rd, checkRd, findHTMLlinks, Rd2txt_options, matchConcordance.

Examples

## Simulate rendering of this (installed) page in HTML and text format
Rd <- Rd_db("tools")[["Rd2HTML.Rd"]]

outfile <- tempfile(fileext = ".html")
Rd2HTML(Rd, outfile, package = "tools") |> browseURL()

outfile <- tempfile(fileext = ".txt")
Rd2txt(Rd, outfile, package = "tools") |> file.show()