From 3d79fa040aa253172fef621d4a38e737e9f9a10a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Tich=C3=BD?= <petr.tichy@gooddata.com>
Date: Thu, 17 Sep 2015 17:50:34 +0200
Subject: [PATCH] Add escape-char option to write-csv

---
 src/clojure_csv/core.clj       | 16 ++++++++++------
 test/clojure_csv/test/core.clj |  8 ++++++++
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/clojure_csv/core.clj b/src/clojure_csv/core.clj
index f5a523a..6e5d616 100644
--- a/src/clojure_csv/core.clj
+++ b/src/clojure_csv/core.clj
@@ -234,16 +234,16 @@ and quotes. The main functions are parse-csv and write-csv."}
   "Given a character, returns the escaped version, whether that is the same
    as the original character or a replacement. The return is a string or a
    character, but it all gets passed into str anyways."
-  [chr delimiter quote-char]
-  (if (= quote-char chr) (str quote-char quote-char) chr))
+  [chr delimiter quote-char escape-char]
+  (if (= quote-char chr) (str escape-char quote-char) chr))
 
 (defn- quote-and-escape
   "Given a string (cell), returns a new string that has any necessary quoting
    and escaping."
-  [cell delimiter quote-char force-quote]
+  [cell delimiter quote-char escape-char force-quote]
   (if (or force-quote (needs-quote? cell delimiter quote-char))
     (str quote-char
-         (apply str (map #(escape % delimiter quote-char)
+         (apply str (map #(escape % delimiter quote-char escape-char)
                                     cell))
          quote-char)
     cell))
@@ -251,10 +251,11 @@ and quotes. The main functions are parse-csv and write-csv."}
 (defn- quote-and-escape-row
   "Given a row (vector of strings), quotes and escapes any cells where that
    is necessary and then joins all the text into a string for that entire row."
-  [row delimiter quote-char force-quote]
+  [row delimiter quote-char escape-char force-quote]
   (string/join delimiter (map #(quote-and-escape %
                                                  delimiter
                                                  quote-char
+                                                 escape-char
                                                  force-quote)
                               row)))
 
@@ -269,15 +270,18 @@ and quotes. The main functions are parse-csv and write-csv."}
                       for writing CSV files.  Default value: \\n
        :quote-char - A character that is used to begin and end a quoted cell.
                      Default value: \\\"
+       :escape-char - A character that is used to escape quoting.
+                     Default value: :quote-char
        :force-quote - Forces every cell to be quoted (useful for Excel interop)
                       Default value: false"
-  [table & {:keys [delimiter quote-char end-of-line force-quote]
+  [table & {:keys [delimiter quote-char escape-char end-of-line force-quote]
             :or {delimiter \, quote-char \" end-of-line "\n"
                  force-quote false}}]
   (loop [csv-string (StringBuilder.)
          quoted-table (map #(quote-and-escape-row %
                                                   (str delimiter)
                                                   quote-char
+                                                  (if (nil? escape-char) quote-char escape-char)
                                                   force-quote)
                            table)]
     (if (empty? quoted-table)
diff --git a/test/clojure_csv/test/core.clj b/test/clojure_csv/test/core.clj
index 7636bf4..299a7f7 100644
--- a/test/clojure_csv/test/core.clj
+++ b/test/clojure_csv/test/core.clj
@@ -84,6 +84,14 @@
   (is (= "a,b\"c,d\n"
          (write-csv [["a", "b\"c", "d"]] :quote-char \|))))
 
+(deftest alternate-escape-char
+  (is (= "quoted:,\"escaped\"quotes\"\"\n"
+         (write-csv [["quoted:" "escaped\"quotes\""]] :escape-char "")))
+  (is (= "quoted:,\"escaped\"\"quotes\"\"\"\n"
+         (write-csv [["quoted:" "escaped\"quotes\""]] :escape-char \")))
+  (is (= "quoted:,\"escaped\\\"quotes\\\"\"\n"
+         (write-csv [["quoted:" "escaped\"quotes\""]] :escape-char \\))))
+
 (deftest strictness
   (is (thrown? Exception (dorun (parse-csv "a,b,c,\"d" :strict true))))
   (is (thrown? Exception (dorun (parse-csv "a,b,c,d\"e" :strict true))))