utils (version 3.3)

rtags: An Etags-like Tagging Utility for R

Description

rtags provides etags-like indexing capabilities for R code, using R's own parser.

Usage

rtags(path = ".", pattern = "\\.[RrSs]$",
      recursive = FALSE,
      src = list.files(path = path, pattern = pattern,
                       full.names = TRUE,
                       recursive = recursive),
      keep.re = NULL,
      ofile = "", append = FALSE,
      verbose = getOption("verbose"))

Arguments

path, pattern, recursive

Arguments passed on to list.files to determine the files to be tagged. By default, these are all files with extension .R, .r, .S, and .s in the current directory. These arguments are ignored if src is specified.

src

A vector of file names to be indexed.

keep.re

A regular expression further restricting src (the files to be indexed). For example, specifying keep.re = "/R/[^/]*\\.R$" will only retain files with extension .R inside a directory named R.

ofile

Passed on to cat as the file argument; typically the output file where the tags will be written ("TAGS" by convention). By default, the output is written to the R console (unless redirected).

append

Logical, indicating whether the output should overwrite an existing file, or append to it.

verbose

Logical. If TRUE, file names are echoed to the R console as they are processed.

Details

Many text editors allow definitions of functions and other language objects to be quickly and easily located in source files through a tagging utility. This functionality requires the relevant source files to be preprocessed, producing an index (or tag) file containing the names and their corresponding locations. There are multiple tag file formats, the most popular being the vi-style ctags format and the and emacs-style etags format. Tag files in these formats are usually generated by the ctags and etags utilities respectively. Unfortunately, these programs do not recognize R code syntax. They do allow tagging of arbitrary language files through regular expressions, but this too is insufficient.

The rtags function is intended to be a tagging utility for R code. It parses R code files (using R's parser) and produces tags in Emacs' etags format. Support for vi-style tags is currently absent, but should not be difficult to add.

References

https://en.wikipedia.org/wiki/Ctags, https://www.gnu.org/software/emacs/manual/html_node/eintr/etags.html

See Also

list.files, cat

Examples

rtags("/path/to/src/repository",
      pattern = "[.]*\\.[RrSs]$",
      keep.re = "/R/",
      verbose = TRUE,
      ofile = "TAGS",
      append = FALSE,
      recursive = TRUE)