Allow for more options in the CSV escape character, fix #38.

To allow for importing JSON one-liners as-is in the database it can be
interesting to leverage the CSV parser in a compatible setup. That setup
requires being able to use any separator character as the escape
character.

pgloader.1.md

@@ -878,10 +878,11 @@ The `csv` format command accepts the following clauses and options:
 
       - *fields escaped by*
 
-	    Takes either the special value *backslash-quote* or *double-quote*.
-	    This value is used to recognize escaped field separators when they
-	    are to be found within the data fields themselves. Defaults to
-	    *double-quote*.
+	    Takes either the special value *backslash-quote* or *double-quote*,
+	    or any value supported by the *fields terminated by* option (see
+	    below). This value is used to recognize escaped field separators
+	    when they are to be found within the data fields themselves.
+	    Defaults to *double-quote*.
 
       - *fields terminated by*
 

src/parsers/command-csv.lisp

@@ -65,7 +65,9 @@
 (defrule backslash-quote "backslash-quote" (:constant "\\\""))
 (defrule escaped-quote-name    (or quote-quote backslash-quote))
 (defrule escaped-quote-literal (or (and #\" #\") (and #\\ #\")) (:text t))
-(defrule escaped-quote         (or escaped-quote-literal escaped-quote-name))
+(defrule escaped-quote         (or escaped-quote-literal
+                                   escaped-quote-name
+                                   separator))
 
 (defrule option-fields-escaped-by (and kw-fields kw-escaped kw-by escaped-quote)
   (:lambda (esc)

test/Makefile

@@ -11,6 +11,7 @@ REGRESS= allcols.load 		    \
          csv-error.load 	    \
          csv-filename-pattern.load  \
          csv-header.load            \
+         csv-json.load              \
          csv-keep-extra-blanks.load \
          csv-nulls.load             \
          csv-trim-extra-blanks.load \

test/csv-json.load

@@ -0,0 +1,30 @@
+LOAD CSV
+     FROM INLINE
+     INTO postgresql:///pgloader?json
+
+     WITH truncate,
+          fields not enclosed,
+          fields terminated by '0x02',
+          fields escaped by '0x02'
+
+   BEFORE LOAD DO
+    $$ drop table if exists json; $$,
+    $$ CREATE TABLE json (json text); $$;
+
+
+
+{"table-name": "fetch","read":0,"imported":0,"errors":0,"time":"0.000s"}
+{"table-name": "fetch meta data","read":8,"imported":8,"errors":0,"time":"0.026s"}
+{"table-name": "create, truncate","read":0,"imported":0,"errors":0,"time":"0.046s"}
+{"table-name": "long","read":0,"imported":2,"errors":0,"time":"0.069s"}
+{"table-name": "blobs","read":0,"imported":1,"errors":0,"time":"0.021s"}
+{"table-name": "unsigned","read":0,"imported":2,"errors":0,"time":"0.007s"}
+{"table-name": "reals","read":0,"imported":3,"errors":0,"time":"0.007s"}
+{"table-name": "ints","read":0,"imported":3,"errors":0,"time":"0.006s"}
+{"table-name": "def","read":0,"imported":2,"errors":0,"time":"0.007s"}
+{"table-name": "stamps","read":0,"imported":2,"errors":0,"time":"0.007s"}
+{"table-name": "character","read":0,"imported":4,"errors":0,"time":"0.005s"}
+{"table-name": "index build completion","read":0,"imported":0,"errors":0,"time":"0.000s"}
+{"table-name": "Create Indexes","read":0,"imported":0,"errors":0,"time":"0.000s"}
+{"table-name": "Reset Sequences","read":0,"imported":0,"errors":0,"time":"0.015s"}
+{"table-name": "Total streaming time","read":0,"imported":19,"errors":0,"time":"0.216s"}

test/regress/expected/csv-json.out

@@ -0,0 +1,15 @@
+{"table-name": "fetch","read":0,"imported":0,"errors":0,"time":"0.000s"},
+{"table-name": "fetch meta data","read":8,"imported":8,"errors":0,"time":"0.026s"},
+{"table-name": "create, truncate","read":0,"imported":0,"errors":0,"time":"0.046s"},
+{"table-name": "long","read":0,"imported":2,"errors":0,"time":"0.069s"},
+{"table-name": "blobs","read":0,"imported":1,"errors":0,"time":"0.021s"},
+{"table-name": "unsigned","read":0,"imported":2,"errors":0,"time":"0.007s"},
+{"table-name": "reals","read":0,"imported":3,"errors":0,"time":"0.007s"},
+{"table-name": "ints","read":0,"imported":3,"errors":0,"time":"0.006s"},
+{"table-name": "def","read":0,"imported":2,"errors":0,"time":"0.007s"},
+{"table-name": "stamps","read":0,"imported":2,"errors":0,"time":"0.007s"},
+{"table-name": "character","read":0,"imported":4,"errors":0,"time":"0.005s"},
+{"table-name": "index build completion","read":0,"imported":0,"errors":0,"time":"0.000s"},
+{"table-name": "Create Indexes","read":0,"imported":0,"errors":0,"time":"0.000s"},
+{"table-name": "Reset Sequences","read":0,"imported":0,"errors":0,"time":"0.015s"},
+{"table-name": "Total streaming time","read":0,"imported":19,"errors":0,"time":"0.216s"}