Add eol argument to write functions

This allows writing with Windows newlines if desired.

Fixes #857

NEWS.md

@@ -7,6 +7,8 @@
 
 ## Additional features and fixes
 
+* `write_*()` functions gain a `eol =` argument to control the end of line character used (#857). This allows writing of CSV files with Windows newlines (CRLF) if desired.
+
 * `write_excel_csv()` no longer outputs a byte order mark when appending to a file (#1075).
 
 * The `read_*` functions now close properly all connections, including on 

R/RcppExports.R

@@ -101,7 +101,7 @@ write_file_raw_ <- function(x, connection) {
     invisible(.Call(`_readr_write_file_raw_`, x, connection))
 }
 
-stream_delim_ <- function(df, connection, delim, na, col_names, bom, quote_escape) {
-    .Call(`_readr_stream_delim_`, df, connection, delim, na, col_names, bom, quote_escape)
+stream_delim_ <- function(df, connection, delim, na, col_names, bom, quote_escape, eol) {
+    .Call(`_readr_stream_delim_`, df, connection, delim, na, col_names, bom, quote_escape, eol)
 }
 

R/write.R

@@ -40,6 +40,8 @@
 #'   "double", "backslash" or "none". You can also use `FALSE`, which is
 #'   equivalent to "none". The default is to double the quotes, which is the
 #'   format excel expects.
+#' @param eol The end of line character to use. Most commonly either "\n" for
+#'   Unix style newlines, or "\r\n" for Windows style newlines.
 #' @return `write_*()` returns the input `x` invisibly.
 #' @references Florian Loitsch, Printing Floating-Point Numbers Quickly and
 #' Accurately with Integers, PLDI '10,
@@ -60,41 +62,41 @@
 #'
 #' \dontshow{setwd(.old_wd)}
 write_delim <- function(x, path, delim = " ", na = "NA", append = FALSE,
-                        col_names = !append, quote_escape = "double") {
+                        col_names = !append, quote_escape = "double", eol = "\n") {
   stopifnot(is.data.frame(x))
 
   x_out <- x
   x[] <- lapply(names(x), function(i) output_column(x[[i]], i))
   stream_delim(x, path, delim = delim, col_names = col_names, append = append,
-    na = na, quote_escape = quote_escape)
+    na = na, quote_escape = quote_escape, eol = eol)
 
   invisible(x_out)
 }
 
 #' @rdname write_delim
 #' @export
 write_csv <- function(x, path, na = "NA", append = FALSE, col_names = !append,
-                      quote_escape = "double") {
+                      quote_escape = "double", eol = "\n") {
   write_delim(x, path, delim = ",", na = na, append = append,
-    col_names = col_names, quote_escape = quote_escape)
+    col_names = col_names, quote_escape = quote_escape, eol = eol)
 }
 
 #' @rdname write_delim
 #' @export
 write_csv2 <- function(x, path, na = "NA", append = FALSE, col_names = !append,
-                       quote_escape = "double") {
+                       quote_escape = "double", eol = "\n") {
   x_out <- x
   x <- change_decimal_separator(x, decimal_mark = ",")
   write_delim(x, path, delim = ";", na = na, append = append,
-    col_names = col_names, quote_escape = quote_escape)
+    col_names = col_names, quote_escape = quote_escape, eol = eol)
 
   invisible(x_out)
 }
 
 #' @rdname write_delim
 #' @export
 write_excel_csv <- function(x, path, na = "NA", append = FALSE,
-                            col_names = !append, delim = ",", quote_escape = "double") {
+                            col_names = !append, delim = ",", quote_escape = "double", eol = "\n") {
 
   stopifnot(is.data.frame(x))
 
@@ -104,31 +106,31 @@ write_excel_csv <- function(x, path, na = "NA", append = FALSE,
 
   x[] <- lapply(x, output_column)
   stream_delim(x, path, delim, col_names = col_names, append = append,
-    na = na, bom = !append, quote_escape = quote_escape)
+    na = na, bom = !append, quote_escape = quote_escape, eol = eol)
 
   invisible(x_out)
 }
 
 #' @rdname write_delim
 #' @export
 write_excel_csv2 <- function(x, path, na = "NA", append = FALSE,
-                             col_names = !append, delim = ";", quote_escape = "double") {
+                             col_names = !append, delim = ";", quote_escape = "double", eol = "\n") {
   x_out <- x
   x <- change_decimal_separator(x, decimal_mark = ",")
 
   datetime_cols <- vapply(x, inherits, logical(1), "POSIXt")
   x[datetime_cols] <- lapply(x[datetime_cols], format, "%Y/%m/%d %H:%M:%S")
 
   x[] <- lapply(x, output_column)
-  write_excel_csv(x, path, na, append, col_names, delim, quote_escape = quote_escape)
+  write_excel_csv(x, path, na, append, col_names, delim, quote_escape = quote_escape, eol = eol)
 
   invisible(x_out)
 }
 
 #' @rdname write_delim
 #' @export
-write_tsv <- function(x, path, na = "NA", append = FALSE, col_names = !append, quote_escape = "double") {
-  write_delim(x, path, delim = '\t', na = na, append = append, col_names = col_names, quote_escape = quote_escape)
+write_tsv <- function(x, path, na = "NA", append = FALSE, col_names = !append, quote_escape = "double", eol = "\n") {
+  write_delim(x, path, delim = '\t', na = na, append = append, col_names = col_names, quote_escape = quote_escape, eol = eol)
 }
 
 #' Convert a data frame to a delimited string
@@ -154,32 +156,32 @@ write_tsv <- function(x, path, na = "NA", append = FALSE, col_names = !append, q
 #' cat(format_csv(df))
 #' @export
 format_delim <- function(x, delim, na = "NA", append = FALSE,
-                         col_names = !append, quote_escape = "double") {
+                         col_names = !append, quote_escape = "double", eol = "\n") {
   stopifnot(is.data.frame(x))
 
   x[] <- lapply(x, output_column)
-  res <- stream_delim(df = x, path = NULL, delim = delim, col_names = col_names, append = append, na = na, quote_escape = quote_escape)
+  res <- stream_delim(df = x, path = NULL, delim = delim, col_names = col_names, append = append, na = na, quote_escape = quote_escape, eol = eol)
   Encoding(res) <- "UTF-8"
   res
 }
 
 #' @export
 #' @rdname format_delim
-format_csv <- function(x, na = "NA", append = FALSE, col_names = !append, quote_escape = "double") {
-  format_delim(x, delim = ",", na = na, append = append, col_names = col_names, quote_escape = quote_escape)
+format_csv <- function(x, na = "NA", append = FALSE, col_names = !append, quote_escape = "double", eol = "\n") {
+  format_delim(x, delim = ",", na = na, append = append, col_names = col_names, quote_escape = quote_escape, eol = eol)
 }
 
 #' @export
 #' @rdname format_delim
-format_csv2 <- function(x, na = "NA", append = FALSE, col_names = !append, quote_escape = "double") {
+format_csv2 <- function(x, na = "NA", append = FALSE, col_names = !append, quote_escape = "double", eol = "\n") {
   x <- change_decimal_separator(x, decimal_mark = ",")
-  format_delim(x, delim = ";", na = na, append = append, col_names = col_names, quote_escape = quote_escape)
+  format_delim(x, delim = ";", na = na, append = append, col_names = col_names, quote_escape = quote_escape, eol = eol)
 }
 
 #' @export
 #' @rdname format_delim
-format_tsv <- function(x, na = "NA", append = FALSE, col_names = !append, quote_escape = "double") {
-  format_delim(x, delim = "\t", na = na, append = append, col_names = col_names, quote_escape = quote_escape)
+format_tsv <- function(x, na = "NA", append = FALSE, col_names = !append, quote_escape = "double", eol = "\n") {
+  format_delim(x, delim = "\t", na = na, append = append, col_names = col_names, quote_escape = quote_escape, eol = eol)
 }
 
 #' Preprocess column for output
@@ -220,7 +222,7 @@ output_column.list <- function(x, name) {
   stop("Flat files can't store the list column `", name, "`", call. = FALSE)
 }
 
-stream_delim <- function(df, path, append = FALSE, bom = FALSE, ..., quote_escape) {
+stream_delim <- function(df, path, append = FALSE, bom = FALSE, ..., quote_escape, eol) {
   quote_escape <- standardise_escape(quote_escape)
 
   path <- standardise_path(path, input = FALSE)
@@ -233,7 +235,7 @@ stream_delim <- function(df, path, append = FALSE, bom = FALSE, ..., quote_escap
       open(path, "wb")
     }
   }
-  stream_delim_(df, path, ..., bom = bom, quote_escape = quote_escape)
+  stream_delim_(df, path, ..., bom = bom, quote_escape = quote_escape, eol = eol)
 }
 
 change_decimal_separator <- function(x, decimal_mark = ",") {

src/RcppExports.cpp

@@ -352,8 +352,8 @@ BEGIN_RCPP
 END_RCPP
 }
 // stream_delim_
-std::string stream_delim_(const List& df, RObject connection, char delim, const std::string& na, bool col_names, bool bom, int quote_escape);
-RcppExport SEXP _readr_stream_delim_(SEXP dfSEXP, SEXP connectionSEXP, SEXP delimSEXP, SEXP naSEXP, SEXP col_namesSEXP, SEXP bomSEXP, SEXP quote_escapeSEXP) {
+std::string stream_delim_(const List& df, RObject connection, char delim, const std::string& na, bool col_names, bool bom, int quote_escape, const char* eol);
+RcppExport SEXP _readr_stream_delim_(SEXP dfSEXP, SEXP connectionSEXP, SEXP delimSEXP, SEXP naSEXP, SEXP col_namesSEXP, SEXP bomSEXP, SEXP quote_escapeSEXP, SEXP eolSEXP) {
 BEGIN_RCPP
     Rcpp::RObject rcpp_result_gen;
     Rcpp::RNGScope rcpp_rngScope_gen;
@@ -364,7 +364,8 @@ BEGIN_RCPP
     Rcpp::traits::input_parameter< bool >::type col_names(col_namesSEXP);
     Rcpp::traits::input_parameter< bool >::type bom(bomSEXP);
     Rcpp::traits::input_parameter< int >::type quote_escape(quote_escapeSEXP);
-    rcpp_result_gen = Rcpp::wrap(stream_delim_(df, connection, delim, na, col_names, bom, quote_escape));
+    Rcpp::traits::input_parameter< const char* >::type eol(eolSEXP);
+    rcpp_result_gen = Rcpp::wrap(stream_delim_(df, connection, delim, na, col_names, bom, quote_escape, eol));
     return rcpp_result_gen;
 END_RCPP
 }
@@ -395,7 +396,7 @@ static const R_CallMethodDef CallEntries[] = {
     {"_readr_write_lines_raw_", (DL_FUNC) &_readr_write_lines_raw_, 3},
     {"_readr_write_file_", (DL_FUNC) &_readr_write_file_, 2},
     {"_readr_write_file_raw_", (DL_FUNC) &_readr_write_file_raw_, 2},
-    {"_readr_stream_delim_", (DL_FUNC) &_readr_stream_delim_, 7},
+    {"_readr_stream_delim_", (DL_FUNC) &_readr_stream_delim_, 8},
     {NULL, NULL, 0}
 };
 

src/write_delim.cpp

@@ -24,7 +24,8 @@ void stream_delim_row(
     int i,
     char delim,
     const std::string& na,
-    quote_escape_t escape) {
+    quote_escape_t escape,
+    const char* eol) {
   int p = Rf_length(x);
 
   for (int j = 0; j < p - 1; ++j) {
@@ -33,7 +34,7 @@ void stream_delim_row(
   }
   stream_delim(output, x.at(p - 1), i, delim, na, escape);
 
-  output << '\n';
+  output << eol;
 }
 
 bool needs_quote(const char* string, char delim, const std::string& na) {
@@ -92,7 +93,8 @@ void stream_delim(
     const std::string& na,
     bool col_names,
     bool bom,
-    quote_escape_t escape) {
+    quote_escape_t escape,
+    const char* eol) {
   int p = Rf_length(df);
   if (p == 0)
     return;
@@ -108,14 +110,14 @@ void stream_delim(
       if (j != p - 1)
         output << delim;
     }
-    output << '\n';
+    output << eol;
   }
 
   RObject first_col = df[0];
   int n = Rf_length(first_col);
 
   for (int i = 0; i < n; ++i) {
-    stream_delim_row(output, df, i, delim, na, escape);
+    stream_delim_row(output, df, i, delim, na, escape, eol);
   }
 }
 
@@ -127,7 +129,8 @@ std::string stream_delim_(
     const std::string& na,
     bool col_names,
     bool bom,
-    int quote_escape) {
+    int quote_escape,
+    const char* eol) {
   if (connection == R_NilValue) {
     std::ostringstream output;
     stream_delim(
@@ -137,7 +140,8 @@ std::string stream_delim_(
         na,
         col_names,
         bom,
-        static_cast<quote_escape_t>(quote_escape));
+        static_cast<quote_escape_t>(quote_escape),
+        eol);
     return output.str();
   } else {
     boost::iostreams::stream<connection_sink> output(connection);
@@ -148,7 +152,8 @@ std::string stream_delim_(
         na,
         col_names,
         bom,
-        static_cast<quote_escape_t>(quote_escape));
+        static_cast<quote_escape_t>(quote_escape),
+        eol);
   }
 
   return "";