[ruby/csv] Improve RDoc for common options (#146)

https://github.com/ruby/csv/commit/223cbee35d

doc/csv/options/common/col_sep.rdoc

@@ -7,39 +7,57 @@ The \String will be transcoded into the data's \Encoding before use.
 Default value:
   CSV::DEFAULT_OPTIONS.fetch(:col_sep) # => "," (comma)
 
-For examples in this section:
+Using the default (comma):
-  ary = ['a', 'b', 'c']
+  str = CSV.generate do |csv|
-
+    csv << [:foo, 0]
-Using the default:
+    csv << [:bar, 1]
-  str = CSV.generate_line(line)
+    csv << [:baz, 2]
-  str # => "a,b,c\n"
+  end
-  ary = CSV.parse_line(str)
+  str # => "foo,0\nbar,1\nbaz,2\n"
-  ary # => ["a", "b", "c"]
+  ary = CSV.parse(str)
+  ary # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]
 
 Using +:+ (colon):
   col_sep = ':'
-  str = CSV.generate_line(ary, col_sep: col_sep)
+  str = CSV.generate(col_sep: col_sep) do |csv|
-  str # => "a:b:c\n"
+    csv << [:foo, 0]
-  ary = CSV.parse_line(str, col_sep: col_sep)
+    csv << [:bar, 1]
-  ary # => [["a", "b", "c"]]
+    csv << [:baz, 2]
+  end
+  str # => "foo:0\nbar:1\nbaz:2\n"
+  ary = CSV.parse(str, col_sep: col_sep)
+  ary # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]
 
 Using +::+ (two colons):
   col_sep = '::'
-  str = CSV.generate_line(ary, col_sep: col_sep)
+  str = CSV.generate(col_sep: col_sep) do |csv|
-  str # => "a::b::c\n"
+    csv << [:foo, 0]
-  ary = CSV.parse_line(str, col_sep: col_sep)
+    csv << [:bar, 1]
-  ary # => [["a", "b", "c"]]
+    csv << [:baz, 2]
+  end
+  str # => "foo::0\nbar::1\nbaz::2\n"
+  ary = CSV.parse(str, col_sep: col_sep)
+  ary # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]
+
+Using <tt>''</tt> (empty string):
+  col_sep = ''
+  str = CSV.generate(col_sep: col_sep) do |csv|
+    csv << [:foo, 0]
+    csv << [:bar, 1]
+    csv << [:baz, 2]
+  end
+  str # => "foo0\nbar1\nbaz2\n"
 
 ---
 
-Raises an exception if given the empty \String:
+Raises an exception if parsing with the empty \String:
   col_sep = ''
   # Raises ArgumentError (:col_sep must be 1 or more characters: "")
-  CSV.parse_line("a:b:c\n", col_sep: col_sep)
+  CSV.parse("foo0\nbar1\nbaz2\n", col_sep: col_sep)
 
 Raises an exception if the given value is not String-convertible:
   col_sep = BasicObject.new
   # Raises NoMethodError (undefined method `to_s' for #<BasicObject:>)
-  CSV.generate_line(line, col_sep: col_sep)
+  CSV.generate(line, col_sep: col_sep)
   # Raises NoMethodError (undefined method `to_s' for #<BasicObject:>)
   CSV.parse(str, col_sep: col_sep)

doc/csv/options/common/quote_char.rdoc

@@ -5,28 +5,38 @@ in both parsing and generating.
 This String will be transcoded into the data's \Encoding before use.
 
 Default value:
-  CSV::DEFAULT_OPTIONS.fetch(:quote_char) # => "\"" (backslash)
+  CSV::DEFAULT_OPTIONS.fetch(:quote_char) # => "\"" (double quote)
 
 This is useful for an application that incorrectly uses <tt>'</tt> (single-quote)
 to quote fields, instead of the correct <tt>"</tt> (double-quote).
 
-Using the default:
+Using the default (double quote):
-  ary = ['a', 'b', '"c"', 'd']
+  str = CSV.generate do |csv|
-  str = CSV.generate_line(ary)
+    csv << ['foo', 0]
-  str # => "a,b,\"\"\"c\"\"\",d\n"
+    csv << ["'bar'", 1]
-  ary = CSV.parse_line(str)
+    csv << ['"baz"', 2]
-  ary # => ["a", "b", "\"c\"", "d"]
+  end
+  str # => "foo,0\n'bar',1\n\"\"\"baz\"\"\",2\n"
+  ary = CSV.parse(str)
+  ary # => [["foo", "0"], ["'bar'", "1"], ["\"baz\"", "2"]]
 
 Using <tt>'</tt> (single-quote):
   quote_char = "'"
-  ary = ['a', 'b', '\'c\'', 'd']
+  str = CSV.generate(quote_char: quote_char) do |csv|
-  str = CSV.generate_line(ary, quote_char: quote_char)
+    csv << ['foo', 0]
-  str # => "a,b,'''c''',d\n"
+    csv << ["'bar'", 1]
-  ary = CSV.parse_line(str, quote_char: quote_char)
+    csv << ['"baz"', 2]
-  ary # => [["a", "b", "'c'", "d"]]
+  end
+  str # => "foo,0\n'''bar''',1\n\"baz\",2\n"
+  ary = CSV.parse(str, quote_char: quote_char)
+  ary # => [["foo", "0"], ["'bar'", "1"], ["\"baz\"", "2"]]
 
 ---
 
 Raises an exception if the \String length is greater than 1:
   # Raises ArgumentError (:quote_char has to be nil or a single character String)
   CSV.new('', quote_char: 'xx')
+
+Raises an exception if the value is not a \String:
+  # Raises ArgumentError (:quote_char has to be nil or a single character String)
+  CSV.new('', quote_char: :foo)

doc/csv/options/common/row_sep.rdoc

@@ -12,7 +12,8 @@ When +row_sep+ is a \String, that \String becomes the row separator.
 The String will be transcoded into the data's Encoding before use.
 
 Using <tt>"\n"</tt>:
-  str = CSV.generate do |csv|
+  row_sep = "\n"
+  str = CSV.generate(row_sep: row_sep) do |csv|
     csv << [:foo, 0]
     csv << [:bar, 1]
     csv << [:baz, 2]
@@ -57,20 +58,28 @@ Using <tt>''</tt> (empty string):
 ---
 
 When +row_sep+ is the \Symbol +:auto+ (the default),
-invokes auto-discovery of the row separator.
+generating uses <tt>"\n"</tt> as the row separator:
-
+  str = CSV.generate do |csv|
-Auto-discovery reads ahead in the data looking for the next <tt>\r\n</tt>, +\n+, or +\r+ sequence.
-The sequence will be selected even if it occurs in a quoted field,
-assuming that you would have the same line endings there.
-
-  row_sep = :auto
-  str = CSV.generate(row_sep: row_sep) do |csv|
     csv << [:foo, 0]
     csv << [:bar, 1]
     csv << [:baz, 2]
   end
   str # => "foo,0\nbar,1\nbaz,2\n"
-  ary = CSV.parse(str, row_sep: row_sep)
+
+Parsing, on the other hand, invokes auto-discovery of the row separator.
+
+Auto-discovery reads ahead in the data looking for the next <tt>\r\n</tt>, +\n+, or +\r+ sequence.
+The sequence will be selected even if it occurs in a quoted field,
+assuming that you would have the same line endings there.
+
+Example:
+  str = CSV.generate do |csv|
+    csv << [:foo, 0]
+    csv << [:bar, 1]
+    csv << [:baz, 2]
+  end
+  str # => "foo,0\nbar,1\nbaz,2\n"
+  ary = CSV.parse(str)
   ary # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]
 
 The default <tt>$INPUT_RECORD_SEPARATOR</tt> (<tt>$/</tt>) is used
@@ -86,6 +95,6 @@ Obviously, discovery takes a little time. Set manually if speed is important. Al
 Raises an exception if the given value is not String-convertible:
   row_sep = BasicObject.new
   # Raises NoMethodError (undefined method `to_s' for #<BasicObject:>)
-  CSV.generate_line(ary, row_sep: row_sep)
+  CSV.generate(ary, row_sep: row_sep)
   # Raises NoMethodError (undefined method `to_s' for #<BasicObject:>)
   CSV.parse(str, row_sep: row_sep)