R/lockfile-read.R

In slopp/renv: Project Environments for R

renv_lockfile_read <- function(file = NULL, text = NULL) {

  contents <- if (is.null(file))
    unlist(strsplit(text, "\n", fixed = TRUE))
  else
    readLines(file, encoding = "UTF-8")

  contents <- grep("^\\s*[#]", contents, value = TRUE, invert = TRUE)
  contents <- contents[nzchar(contents)]
  contents <- paste(contents, collapse = "\n")

  splat <- strsplit(contents, "\\n+(?=\\[)", perl = TRUE)[[1]]

  idx <- regexpr("(?:\\n|$)", splat)
  section <- substring(splat, 1, idx - 1)
  body <- substring(splat, idx + 1)
  names(body) <- substring(section, 2, nchar(section) - 1)

  fields <- enumerate(body, renv_lockfile_read_fields)

  data <- list()
  enumerate(fields, function(section, entries) {
    splat <- strsplit(section, "/", fixed = TRUE)[[1]]

    for (i in seq_len(length(splat) - 1)) {
      k <- splat[1:i]
      if (is.null(data[[k]]))
        data[[k]] <<- list()
    }

    data[[splat]] <<- entries
  })

  class(data) <- "renv_lockfile"
  data

}

renv_lockfile_read_fields <- function(section, fields) {
  parts <- strsplit(fields, "\\n(?!\\s)", perl = TRUE)[[1]]

  idx <- regexpr("=", parts, fixed = TRUE)
  keys <- substring(parts, 1, idx - 1)
  vals <- trimws(substring(parts, idx + 1))
  names(vals) <- keys

  enumerate(vals, renv_lockfile_read_field, section = section)
}

renv_lockfile_read_field <- function(key, value, section) {
  serializer <- renv_lockfile_serializer(section, key)
  serializer$decode(value)
}