R/Rnw2Rmd.R

In mdsr-book/mdsr: Complement to 'Modern Data Science with R'

globalVariables(c("."))

#' Convert Rnw to Rmd
#' @inheritParams fs::file_move
#' @export

# inspiration
# https://github.com/dtkaplan/detex/blob/master/R/replace_tex.R
# https://github.com/ajrgodfrey/BrailleR/blob/master/R/Rnw2Rmd.R

Rnw2Rmd <- function(path, new_path = NULL) {
  if (is.null(new_path)) {
    new_path <- path %>%
      gsub(".Rnw", ".Rmd", .) %>%
      gsub(".tex", ".Rmd", .) %>%
      fs::fs_path()
  }
  x <- readLines(path)
  # chunks
  x <- gsub("(<<)(.*)(>>=)", "```{r \\2}", x)
  x <- gsub("^@", "```", x)
  x <- gsub("(\\\\Sexpr\\{)([^\\}]+)(\\})", "`r \\2`", x)
  # sections  
  x <- gsub("(\\\\chapter\\{)([^\\}]+)(\\})", "# \\2", x)
  x <- gsub("(\\\\section\\{)([^\\}]+)(\\})", "## \\2", x)
  x <- gsub("(\\\\subsection\\{)([^\\}]+)(\\})", "### \\2", x)
  x <- gsub("(\\\\subsubsection\\{)([^\\}]+)(\\})", "#### \\2", x)
  # references
  x <- gsub("(\\\\citep\\{)([^\\}]+)(\\})", "[@\\2]", x)
  x <- gsub("(\\\\cite\\{)([^\\}]+)(\\})", "@\\2", x)
  x <- gsub("(\\\\ref\\{)([^\\}]+)(\\})", "\\\\@ref(\\2)", x)
  x <- gsub("(\\\\label\\{)([^\\}]+)(\\})", "{#\\2}", x)
  x <- gsub("(\\\\index\\{)([^\\}]+)(\\})(\\{)([^\\}]+)(\\})\\%", "\\\\index{\\2}{\\5}", x)
  # LaTeX
  x <- gsub("\\\\item", "- ", x)
  x <- gsub("(\\\\emph\\{)([^\\}]+)(\\})", "*\\2*", x)
  x <- gsub("(\\\\textit\\{)([^\\}]+)(\\})", "*\\2*", x)
  x <- gsub("(\\\\textbf\\{)([^\\}]+)(\\})", "**\\2**", x)
  x <- gsub("(\\\\href\\{)([^\\}]+)(\\})(\\{)([^\\}]+)(\\})", "[\\5](\\2)", x)
  x <- gsub("(\\\\url\\{)([^\\}]+)(\\})", "(\\2)", x)
#  x <- gsub('(``)(.+)(\\")', '"\\2"', x)
  
  x <- gsub("{\\\\tt ([a-zA-Z0-9. _()=]*)} ", "`\\1` ", x, perl = TRUE)  # need to clean up {`
#  x <- gsub("\\index{R}", "setindex{r}\\\\index", x, perl = TRUE)
#  x <- gsub("\\index{subject}", "setindex{subject}\\\\index", x, perl = TRUE)
  writeLines(x, new_path)
}