excerptr is an R interface to the python package excerpts. See there for more on the Why.
Suppose you have a script
path <- system.file("tests", "files", "some_file.R", package = "excerptr")
cat(readLines(path), sep = "\n")
and you would want to excerpt the comments marked by ‘%’ into a file giving you the table of contents of your script. Then
gives you
If you have pandoc installed, you can convert the markdown output into html:
is_pandoc_installed <- nchar(Sys.which("pandoc")) > 0 &&
nchar(Sys.which("pandoc-citeproc")) > 0
is_pandoc_version_sufficient <- FALSE
if (is_pandoc_installed) {
reference <- "1.12.3"
version <- strsplit(system2(Sys.which("pandoc"), "--version", stdout = TRUE),
split = " ")[[1]][2]
if (utils::compareVersion(version, reference) >= 0)
is_pandoc_version_sufficient <- TRUE
}
if (is_pandoc_version_sufficient)
excerptr::excerptr(file_name = path, pandoc_formats = "html",
output_path = tempdir())
This runs pandoc on your excerpted comments and generates an html file you can view via:
if (is_pandoc_version_sufficient)
cat(readLines(file.path(tempdir(), sub("\\.R$", ".html", basename(path)))),
sep = "\n")
You browse it via