R/io.R

In rijpma/cower: Convert csvs to nquads using json-ld data description

#' @import data.table
#' @export
nqwrite = function(dat, nquadpath, 
    append = FALSE, compress = TRUE){

    if (compress & stringi::stri_sub(nquadpath, -3, -1) != ".gz"){
        warning(paste("compress == ", compress, "and file", nquadpath, "does not end in .gz"))
    }

    if (append & !file.exists(nquadpath)){
        stop(paste("'append' is", append, ", but", nquadpath, "does not exist."))
    }

    if (append) writemode = 'a' else writemode = 'w'

    if (compress) {
        outfile = gzfile(nquadpath, open = writemode)
    } else {
        outfile = file(nquadpath, open = writemode)
    }

    write.table(dat[complete.cases(pred, obj), list(sub, pred, obj, graph)], 
        file = outfile, sep = ' ', quote = F, 
        col.names = F, row.names = F, eol = " .\n")

    close(outfile)
}