* ext/json: Merge json gem 1.5.4+ (f7f78896607b6f6226cd).

[Bug #4700]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32493 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/json/lib/json.rb

@@ -1,3 +1,55 @@
+##
+# = JavaScript Object Notation (JSON)
+#
+# JSON is a lightweight data-interchange format. It is easy for us
+# humans to read and write. Plus, equally simple for machines to generate or parse.
+# JSON is completely language agnostic, making it the ideal interchange format.
+#
+# Built on two universally available structures:
+#   1. A collection of name/value pairs. Often referred to as an _object_, hash table, record, struct, keyed list, or associative array.
+#   2. An orderd list of values. More commonly named as an _array_, vector, sequence, or list.
+#
+# To read more about JSON visit: http://json.org
+#
+# == Parsing JSON
+#
+# To parse a JSON string received by another application, or generated within
+# your existing application:
+#
+#   require 'json'
+#
+#   my_hash = JSON.parse('{"hello": "goodbye"}')
+#   puts my_hash["hello"] => "goodbye"
+#
+# Notice the extra quotes <tt>''</tt> around the hash notation. Ruby expects
+# the argument to be a string and can't convert objects like a hash or array.
+#
+# Ruby converts your string into a hash
+#
+# == Generating JSON
+#
+# Creating a JSON string for communication or serialization is
+# just as simple.
+#
+#   require 'json'
+#
+#   my_hash = {:hello => "goodbye"}
+#   puts JSON.generate(my_hash) => "{\"hello\":\"goodbye\"}"
+#
+# Or an alternative way:
+#
+#   require 'json'
+#   puts {:hello => "goodbye"}.to_json => "{\"hello\":\"goodbye\"}"
+#
+# <tt>JSON.generate</tt> only allows objects or arrays to be converted
+# to JSON syntax. While <tt>to_json</tt> accepts many Ruby classes
+# even though it only acts a method for serialization:
+#
+#   require 'json'
+#
+#   1.to_json => "1"
+#
+
 require 'json/common'
 module JSON
   require 'json/version'