R/detectives.R

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#' Simple detective
#'
#' This detective only uses semantic information to make its
#' investigation.
#' @param x output of the parser. The detective is only interested in the
#'          \samp{token} column of the data.
#' @param \dots ignored
#' @return a vector of styles grouping similar tokens together
#' @examples
#' \dontrun{
#' p <- parse( text = deparse( jitter ), keep.source=TRUE )
#' simple_detective( p )
#' }
#' @export
simple_detective <- function(x, ...) {
  data <- getParseData(x)
  desc <- as.character(data[data[["terminal"]], "token"])
  styles <- character(length(desc))

  styles[desc == "COMMENT"] <- "comment"
  styles[desc == "ROXYGEN_COMMENT"] <- "roxygencomment"

  styles[grepl("^'.*?'$", desc)] <- "keyword"
  styles[
    desc %in%
      c(
        "FUNCTION",
        "FOR",
        "IN",
        "IF",
        "ELSE",
        "WHILE",
        "NEXT",
        "BREAK",
        "REPEAT",
        "AND",
        "AND2",
        "OR",
        "OR2",
        "GT",
        "LT",
        "GE",
        "LBB",
        "NE",
        "SPECIAL",
        "NS_GET_INT",
        "NS_GET"
      )
  ] <- "keyword"

  styles[desc == "STR_CONST"] <- "string"
  styles[desc == "NUM_CONST"] <- "number"

  styles[desc == "SYMBOL_FUNCTION_CALL"] <- "functioncall"
  styles[desc %in% c("SYMBOL_SUB", "EQ_SUB")] <- "argument"
  styles[desc == "SYMBOL_PACKAGE"] <- "package"

  styles[desc %in% c("SYMBOL_FORMALS")] <- "formalargs"
  styles[desc %in% "EQ_FORMALS"] <- "eqformalargs"

  styles[desc %in% c("EQ_ASSIGN", "LEFT_ASSIGN")] <- "assignement"
  styles[desc == "SYMBOL"] <- "symbol"
  styles[desc == "SLOT"] <- "slot"
  styles
}