Rework CSV and Fixed files source fields options, see #116.

It's not possible to use a comma separator when using more than one
source field option at the same time, and for better readability the
options are to be found enclosed in squared brackets.

Also, it's now possible to spell out "from" and "for" keywords on the
source definitions, making it easier to read and maintain the load file,
as in this full example:

          (
           a from  0 for 10,
           b from 10 for  8,
           c from 18 for  8,
           d from 26 for 17 [null if blanks, trim right whitespace]
          )

pgloader.1

@@ -1,7 +1,7 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "PGLOADER" "1" "September 2014" "ff" ""
+.TH "PGLOADER" "1" "October 2014" "ff" ""
 .
 .SH "NAME"
 \fBpgloader\fR \- PostgreSQL data loader
@@ -516,7 +516,7 @@ The optional \fIIN DIRECTORY\fR clause allows specifying which directory to walk
 The \fIFROM\fR option also supports an optional comma separated list of \fIfield\fR names describing what is expected in the \fBCSV\fR data file, optionally introduced by the clause \fBHAVING FIELDS\fR\.
 .
 .IP
-Each field name can be either only one name or a name following with specific reader options for that field\. Supported per\-field reader options are:
+Each field name can be either only one name or a name following with specific reader options for that field, enclosed in square brackets and comma\-separated\. Supported per\-field reader options are:
 .
 .IP "\(bu" 4
 \fIterminated by\fR
@@ -639,7 +639,13 @@ This command instructs pgloader to load data from a text file containing columns
 .nf
 
 LOAD FIXED
-     FROM inline (a 0 10, b 10 8, c 18 8, d 26 17)
+     FROM inline
+          (
+           a from  0 for 10,
+           b from 10 for  8,
+           c from 18 for  8,
+           d from 26 for 17 [null if blanks, trim right whitespace]
+          )
      INTO postgresql:///pgloader?fixed
           (
              a, b,
@@ -666,6 +672,8 @@ BEFORE LOAD DO
  01234567892008052011431250firstline
     01234562008052115182300left blank\-padded
  12345678902008052208231560another line
+  2345609872014092914371500
+  2345678902014092914371520
 .
 .fi
 .
@@ -715,6 +723,11 @@ Position in the line where to start reading that field\'s value\. Can be entered
 .IP
 How many bytes to read from the \fIstart\fR position to read that field\'s value\. Same format as \fIstart\fR\.
 .
+.IP "" 0
+.
+.IP
+Those optional parameters can enclosed in square brackets and comma\-separated:
+.
 .IP "\(bu" 4
 \fIterminated by\fR
 .

pgloader.1.md

@@ -465,8 +465,8 @@ The `csv` format command accepts the following clauses and options:
 	optionally introduced by the clause `HAVING FIELDS`.
 
 	Each field name can be either only one name or a name following with
-	specific reader options for that field. Supported per-field reader
+	specific reader options for that field, enclosed in square brackets and
-	options are:
+	comma-separated. Supported per-field reader options are:
 
 	  - *terminated by*
 
@@ -576,7 +576,13 @@ This command instructs pgloader to load data from a text file containing
 columns arranged in a *fixed size* manner. Here's an example:
 
     LOAD FIXED
-         FROM inline (a 0 10, b 10 8, c 18 8, d 26 17)
+         FROM inline
+              (
+               a from  0 for 10,
+               b from 10 for  8,
+               c from 18 for  8,
+               d from 26 for 17 [null if blanks, trim right whitespace]
+              )
          INTO postgresql:///pgloader?fixed
               (
                  a, b,
@@ -603,6 +609,8 @@ columns arranged in a *fixed size* manner. Here's an example:
      01234567892008052011431250firstline
         01234562008052115182300left blank-padded
      12345678902008052208231560another line
+      2345609872014092914371500                 
+      2345678902014092914371520
 
 The `fixed` format command accepts the following clauses and options:
 
@@ -642,6 +650,9 @@ The `fixed` format command accepts the following clauses and options:
 	    How many bytes to read from the *start* position to read that
 	    field's value. Same format as *start*.
 
+    Those optional parameters can enclosed in square brackets and
+	comma-separated:
+
 	  - *terminated by*
 
 		See the description of *field terminated by* below.

src/parser.lisp

@@ -120,6 +120,8 @@
   (def-keyword-rule "left")
   (def-keyword-rule "right")
   (def-keyword-rule "whitespace")
+  (def-keyword-rule "from")
+  (def-keyword-rule "for")
   (def-keyword-rule "skip")
   (def-keyword-rule "header")
   (def-keyword-rule "null")
@@ -1721,6 +1723,28 @@ load database
                               option-trim-left-whitespace
                               option-trim-right-whitespace))
 
+(defrule another-csv-field-option (and comma csv-field-option)
+  (:lambda (field-option)
+    (destructuring-bind (comma option) field-option
+      (declare (ignore comma))
+      option)))
+
+(defrule open-square-bracket (and ignore-whitespace #\[ ignore-whitespace)
+  (:constant :open-square-bracket))
+(defrule close-square-bracket (and ignore-whitespace #\] ignore-whitespace)
+  (:constant :close-square-bracket))
+
+(defrule csv-field-option-list (and open-square-bracket
+                                    csv-field-option
+                                    (* another-csv-field-option)
+                                    close-square-bracket)
+  (:lambda (option)
+    (destructuring-bind (open opt1 opts close) option
+      (declare (ignore open close))
+      (alexandria:alist-plist `(,opt1 ,@opts)))))
+
+(defrule csv-field-options (? (or csv-field-option csv-field-option-list)))
+
 (defrule csv-field-options (* csv-field-option)
   (:lambda (options)
     (alexandria:alist-plist options)))
@@ -2038,11 +2062,11 @@ load database
 
 (defrule number (or hex-number dec-number))
 
-(defrule field-start-position (and ignore-whitespace number)
+(defrule field-start-position (and (? kw-from) ignore-whitespace number)
-  (:destructure (ws pos) (declare (ignore ws)) pos))
+  (:destructure (from ws pos) (declare (ignore from ws)) pos))
 
-(defrule fixed-field-length (and ignore-whitespace number)
+(defrule fixed-field-length (and (? kw-for) ignore-whitespace number)
-  (:destructure (ws len) (declare (ignore ws)) len))
+  (:destructure (for ws len) (declare (ignore for ws)) len))
 
 (defrule fixed-source-field (and csv-field-name
 				 field-start-position fixed-field-length

test/fixed.load

@@ -13,11 +13,11 @@
 
 LOAD FIXED
      FROM inline
-          ( -- col start length opts
+          (
-               a    0     10,
+           a from  0 for 10,
-               b    10     8,
+           b from 10 for  8,
-               c    18     8,
+           c from 18 for  8,
-               d    26    17 null if blanks trim right whitespace
+           d from 26 for 17 [null if blanks, trim right whitespace]
           )
      INTO postgresql:///pgloader?fixed
           (