Add extra docs for CSV classes

lib/csv/fields_converter.rb

@@ -3,6 +3,22 @@
 class CSV
   class FieldsConverter
     include Enumerable
+    #
+    # A CSV::FieldsConverter is a data structure for storing the
+    # fields converter properties to be passed as a parameter
+    # when parsing a new file (e.g. CSV::Parser.new(@io, parser_options))
+    #
+    # FieldsConverter options:
+    # 1. The option +converters+ stores all the converters added by you
+    # when calling the CSV::FieldsConverter.add_converter method.
+    # 2. The option +builtin_converters+ stores the following converter parsers:
+    # - :integer
+    # - :float
+    # - :date
+    # - :date_time
+    # - :numeric
+    # - :all
+    #
 
     def initialize(options={})
       @converters = []

lib/csv/parser.rb

@@ -12,6 +12,16 @@
 
 class CSV
   class Parser
+    #
+    # A CSV::Parser is m17n aware. The parser works in the Encoding of the IO
+    # or String object being read from or written to. Your data is never transcoded
+    # (unless you ask Ruby to transcode it for you) and will literally be parsed in
+    # the Encoding it is in. Thus CSV will return Arrays or Rows of Strings in the
+    # Encoding of your data. This is accomplished by transcoding the parser itself
+    # into your Encoding.
+    #
+
+    # Raised when encoding is invalid
     class InvalidEncoding < StandardError
     end
 

lib/csv/writer.rb

@@ -7,6 +7,10 @@
 
 class CSV
   class Writer
+    #
+    # A CSV::Writer receives an output, prepares the header, format and output.
+    # It allows us to write new rows in the object and rewind it.
+    #
     attr_reader :lineno
     attr_reader :headers
 
@@ -22,6 +26,9 @@ def initialize(output, options)
       @fields_converter = @options[:fields_converter]
     end
 
+    #
+    # Adds a new row
+    #
     def <<(row)
       case row
       when Row
@@ -47,6 +54,9 @@ def <<(row)
       self
     end
 
+    #
+    # Winds back to the beginning
+    #
     def rewind
       @lineno = 0
       @headers = nil if @options[:headers].nil?