R/pos.R

In RmecabKo: An 'Rcpp' Interface for Eunjeon Project

# Generated by using Rcpp::compileAttributes() -> do not edit by hand
# Generator token: 10BE3573-1514-4C36-9D1C-5A225CD40393

#' POS tagging by mecab-ko
#'
#' \code{pos} returns part-of-speech (POS) tagged morpheme of Korean phrases.
#' 
#' This is a basic function of part-of-speech tagging by mecab-ko.
#'
#' @param phrase Character vector.
#' @param join Boolean.
#' @return List of POS tagged morpheme will be returned in conjoined character vecter form. Element name of the list are original phrases. If \code{join=FALSE}, it returns list of morpheme with named with tags.
#'
#' See examples in \href{https://github.com/junhewk/RmecabKo}{Github}.
#' 
#' @examples 
#' \dontrun{
#' pos(c("Some Korean Phrases"))
#' pos(c("Some Korean Phrases"), join=FALSE)
#' }
#' 
#' @importFrom utils localeToCharset
#' @export
pos <- function(phrase, join = TRUE) {
  if (typeof(phrase) != "character") {
    stop("'phrase' must be a character vector")
  }
  
	if(is_osx() | is_linux()) {
	  
		dicpath <- "/usr/local/lib/mecab/dic/mecab-ko-dic"
		
		if(dir.exists(dicpath)) {
		  dicpath <- paste0("-d ", dicpath)
		} else {
		  stop(paste0("Mecab-ko-dic is not found on ", dicpath, ". Please check https://bitbucket.org/eunjeon/mecab-ko-dic."))
		}

		# Rcpp function to tagging
  	tagged <- posRcpp(phrase, dicpath, join)
		
	} else if(is_windows()) {
    
    if(!mecab_installed()) {
      stop("Mecab binary is not installed. Please run install_mecab().")
    }
	  
	  mecabLibs <- getOption("mecab.libpath")
	  
		# loading /inst/mecab/mecab.exe (mecab-ko-msvc) with system.file and system
    mecabKo <- utils::shortPathName(file.path(mecabLibs, "mecab.exe"))
    # mecabKoDic root in not working
    mecabKoRc <- utils::shortPathName(file.path(mecabLibs, "mecabrc"))
    mecabKoDic <- utils::shortPathName(file.path(mecabLibs, "mecab-ko-dic"))
    
		# saving phrase to UTF-8 txt file
		phraseFile <- utils::shortPathName(tempfile())

		con <- file(phraseFile, "a", encoding = "UTF-8")
		tryCatch({
		  cat(iconv(phrase, from = utils::localeToCharset()[1], to = "UTF-8"), file=con, sep="\n")
		},
		finally = {
		  close(con)
		})
		
  	outputFile <- utils::shortPathName(tempfile())
  	
  	mecabOption <- c("-r", mecabKoRc, "-d", mecabKoDic, "-o", outputFile, phraseFile)
  	
  	# run mecab.exe
  	system2(mecabKo, mecabOption)

  	con <- file(outputFile, "r")
  	posResult <- readLines(con, encoding="UTF-8")
  	close(con)
  	
  	i <- 1
  	tagged <- list()
  	length(tagged) <- i
  	
    for(line in seq(1, length(posResult), 1)) {
      
      taggedLine <- c()
      
      if(posResult[line] == "EOS") {
        i <- i + 1
        if (line != length(posResult)) length(tagged) <-  i
      } else if(substring(posResult[line], 1, 1) == ",") {
        if (join) {
          taggedLine <- c(taggedLine, ",/SC")  
        } else {
          taggedLine["SC"] = ","
        }
      } else {
        taggedElements <- strsplit(posResult[line], ",")
        if (join) {
          taggedLine <- c(taggedLine, gsub("\t", "/", taggedElements[[1]][1]))
        } else {
          taggedMorpheme <- strsplit(taggedElements[[1]][1], "\t")
          taggedLine[taggedMorpheme[[1]][2]] <- taggedMorpheme[[1]][1]
        }
        tagged[[i]] <- c(tagged[[i]], taggedLine)
      }
    }
  	
  	suppressWarnings(file.remove(phraseFile))
  	suppressWarnings(file.remove(outputFile))
	} 
  names(tagged) <- phrase
  
  return(tagged)
}