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authorBurdetteLamar <burdettelamar@yahoo.com>2020-05-06 07:59:54 -0500
committerHiroshi SHIBATA <hsbt@ruby-lang.org>2020-07-01 18:47:50 +0900
commit4689fd5f9982a148052d76e8e1a7bd85256baec6 (patch)
tree3c329cf9bc2375134bb256e8ffdd28a51427e434 /ext/json/lib/json.rb
parent1351374bd14d4d134726889ba195609b4f745ea6 (diff)
[flori/json] Rdoc enhancements
https://github.com/flori/json/commit/e7e3732130
Diffstat (limited to 'ext/json/lib/json.rb')
-rw-r--r--ext/json/lib/json.rb441
1 files changed, 379 insertions, 62 deletions
diff --git a/ext/json/lib/json.rb b/ext/json/lib/json.rb
index 151d9c2f26..a96f4bc612 100644
--- a/ext/json/lib/json.rb
+++ b/ext/json/lib/json.rb
@@ -2,88 +2,405 @@
require 'json/common'
##
-# = JavaScript Object Notation (JSON)
+# = 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.
+# \JSON is a lightweight data-interchange format.
#
-# Built on two universally available structures:
+# A \JSON value is one of the following:
+# - Double-quoted text: <tt>"foo"</tt>.
+# - Number: +1+, +1.0+, +2.0e2+.
+# - Boolean: +true+, +false+.
+# - Null: +null+.
+# - \Array: an ordered list of values, enclosed by square brackets:
+# ["foo", 1, 1.0, 2.0e2, true, false, null]
#
-# 1. A collection of name/value pairs. Often referred to as an _object_, hash table,
-# record, struct, keyed list, or associative array.
-# 2. An ordered list of values. More commonly called an _array_, vector, sequence or
-# list.
+# - \Object: a collection of name/value pairs, enclosed by curly braces;
+# each name is double-quoted text;
+# the values may be any \JSON values:
+# {"a": "foo", "b": 1, "c": 1.0, "d": 2.0e2, "e": true, "f": false, "g": null}
#
-# To read more about JSON visit: http://json.org
+# A \JSON array or object may contain nested arrays, objects, and scalars
+# to any depth:
+# {"foo": {"bar": 1, "baz": 2}, "bat": [0, 1, 2]}
+# [{"foo": 0, "bar": 1}, ["baz", 2]]
#
-# == Parsing JSON
-#
-# To parse a JSON string received by another application or generated within
-# your existing application:
+# == Using \Module \JSON
#
+# To make module \JSON available in your code, begin with:
# require 'json'
#
-# my_hash = JSON.parse('{"hello": "goodbye"}')
-# puts my_hash["hello"] # => "goodbye"
+# All examples here assume that this has been done.
#
-# 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.
+# === Parsing \JSON
#
-# Ruby converts your string into a hash
+# You can parse a \String containing \JSON data using
+# either of two methods:
+# - <tt>JSON.parse(source, opts)</tt>
+# - <tt>JSON.parse!(source, opts)</tt>
#
-# == Generating JSON
+# where
+# - +source+ is a Ruby object.
+# - +opts+ is a \Hash object containing options
+# that control both input allowed and output formatting.
#
-# Creating a JSON string for communication or serialization is
-# just as simple.
+# The difference between the two methods
+# is that JSON.parse! omits some checks
+# and may not be safe for some +source+ data;
+# use it only for data from trusted sources.
+# Use the safer method JSON.parse for less trusted sources.
#
-# require 'json'
+# ==== Parsing \JSON Arrays
#
-# my_hash = {:hello => "goodbye"}
-# puts JSON.generate(my_hash) # => "{\"hello\":\"goodbye\"}"
+# When +source+ is a \JSON array, JSON.parse by default returns a Ruby \Array:
+# json = '["foo", 1, 1.0, 2.0e2, true, false, null]'
+# ruby = JSON.parse(json)
+# ruby # => ["foo", 1, 1.0, 200.0, true, false, nil]
+# ruby.class # => Array
#
-# Or an alternative way:
+# The \JSON array may contain nested arrays, objects, and scalars
+# to any depth:
+# json = '[{"foo": 0, "bar": 1}, ["baz", 2]]'
+# JSON.parse(json) # => [{"foo"=>0, "bar"=>1}, ["baz", 2]]
#
-# require 'json'
-# puts({:hello => "goodbye"}.to_json) # => "{\"hello\":\"goodbye\"}"
+# ==== Parsing \JSON \Objects
+#
+# When the source is a \JSON object, JSON.parse by default returns a Ruby \Hash:
+# json = '{"a": "foo", "b": 1, "c": 1.0, "d": 2.0e2, "e": true, "f": false, "g": null}'
+# ruby = JSON.parse(json)
+# ruby # => {"a"=>"foo", "b"=>1, "c"=>1.0, "d"=>200.0, "e"=>true, "f"=>false, "g"=>nil}
+# ruby.class # => Hash
+#
+# The \JSON object may contain nested arrays, objects, and scalars
+# to any depth:
+# json = '{"foo": {"bar": 1, "baz": 2}, "bat": [0, 1, 2]}'
+# JSON.parse(json) # => {"foo"=>{"bar"=>1, "baz"=>2}, "bat"=>[0, 1, 2]}
+#
+# ==== Parsing \JSON Scalars
+#
+# When the source is a \JSON scalar (not an array or object),
+# JSON.parse returns a Ruby scalar.
+#
+# \String:
+# ruby = JSON.parse('"foo"')
+# ruby # => "foo"
+# ruby.class # => String
+# \Integer:
+# ruby = JSON.parse('1')
+# ruby # => 1
+# ruby.class # => Integer
+# \Float:
+# ruby = JSON.parse('1.0')
+# ruby # => 1.0
+# ruby.class # => Float
+# ruby = JSON.parse('2.0e2')
+# ruby # => 200
+# ruby.class # => Float
+# Boolean:
+# ruby = JSON.parse('true')
+# ruby # => true
+# ruby.class # => TrueClass
+# ruby = JSON.parse('false')
+# ruby # => false
+# ruby.class # => FalseClass
+# Null:
+# ruby = JSON.parse('null')
+# ruby # => nil
+# ruby.class # => NilClass
+#
+# === Generating \JSON
+#
+# To generate a Ruby \String containing \JSON data,
+# use method <tt>JSON.generate(source, opts)</tt>, where
+# - +source+ is a Ruby object.
+# - +opts+ is a \Hash object containing options
+# that control both input allowed and output formatting.
+#
+# ==== Generating \JSON from Arrays
+#
+# When the source is a Ruby \Array, JSON.generate returns
+# a \String containing a \JSON array:
+# ruby = [0, 's', :foo]
+# json = JSON.generate(ruby)
+# json # => "[0,\"s\",\"foo\"]"
+#
+# The Ruby \Array array may contain nested arrays, hashes, and scalars
+# to any depth:
+# ruby = [0, [1, 2], {foo: 3, bar: 4}]
+# json = JSON.generate(ruby)
+# json # => "[0,[1,2],{\"foo\":3,\"bar\":4}]"
+#
+# ==== Generating \JSON from Hashes
+#
+# When the source is a Ruby \Hash, JSON.generate returns
+# a \String containing a \JSON object:
+# ruby = {foo: 0, bar: 's', baz: :bat}
+# json = JSON.generate(ruby)
+# json # => "{\"foo\":0,\"bar\":\"s\",\"baz\":\"bat\"}"
+#
+# The Ruby \Hash array may contain nested arrays, hashes, and scalars
+# to any depth:
+# ruby = {foo: [0, 1], bar: {baz: 2, bat: 3}, bam: :bad}
+# json = JSON.generate(ruby)
+# json # => "{\"foo\":[0,1],\"bar\":{\"baz\":2,\"bat\":3},\"bam\":\"bad\"}"
+#
+# ==== Generating \JSON from Other Objects
+#
+# When the source is neither an \Array nor a \Hash,
+# the generated \JSON data depends on the class of the source.
+#
+# When the source is a Ruby \Integer or \Float, JSON.generate returns
+# a \String containing a \JSON number:
+# JSON.generate(Integer(0)) # => "0""
+# JSON.generate(Float(1.0)) # => "1.0"
+#
+# When the source is a Ruby \String, JSON.generate returns
+# a \String containing a \JSON string (with double-quotes):
+# JSON.generate('A string') # => "\"A string\""
+#
+# When the source is +true+, +false+ or +nil+, JSON.generate returns
+# a \String containing the corresponding \JSON token:
+# JSON.generate(true) # => "true"
+# JSON.generate(false) # => "false"
+# JSON.generate(nil) # => "null"
+#
+# When the source is none of the above, JSON.generate returns
+# a \String containing a \JSON string representation of the source:
+# JSON.generate(:foo) # => "\"foo\""
+# JSON.generate(Complex(0, 0)) # => "\"0+0i\""
+# JSON.generate(Dir.new('.')) # => "\"#<Dir:0x0000000006bb30b8>\""
+#
+# == \JSON Additions
+#
+# When you "round trip" a non-\String object from Ruby to \JSON and back,
+# you have a new \String, instead of the object you began with:
+# ruby0 = Range.new(0, 2)
+# json = JSON.generate(ruby0)
+# json # => "\"0..2\""
+# ruby1 = JSON.parse(json)
+# ruby1 # => "0..2"
+# ruby1.class # => String
+#
+# You can use \JSON _additions_ to preserve the original object.
+# The addition is an extension of a ruby class, so that:
+# - \JSON.generate stores more information in the \JSON string.
+# - \JSON.parse, called with option +create_additions+,
+# uses that information to create a proper Ruby object.
#
-# <tt>JSON.generate</tt> only allows objects or arrays to be converted
-# to JSON syntax. <tt>to_json</tt>, however, accepts many Ruby classes
-# even though it acts only as a method for serialization:
+# This example shows a \Range being generated into \JSON
+# and parsed back into Ruby, both without and with
+# the addition for \Range:
+# ruby = Range.new(0, 2)
+# # This passage does not use the addition for Range.
+# json0 = JSON.generate(ruby)
+# ruby0 = JSON.parse(json0)
+# # This passage uses the addition for Range.
+# require 'json/add/range'
+# json1 = JSON.generate(ruby)
+# ruby1 = JSON.parse(json1, create_additions: true)
+# # Make a nice display.
+# display = <<EOT
+# Generated JSON:
+# Without addition: #{json0} (#{json0.class})
+# With addition: #{json1} (#{json1.class})
+# Parsed JSON:
+# Without addition: #{ruby0.inspect} (#{ruby0.class})
+# With addition: #{ruby1.inspect} (#{ruby1.class})
+# EOT
+# puts display
#
+# This output shows the different results:
+# Generated JSON:
+# Without addition: "0..2" (String)
+# With addition: {"json_class":"Range","a":[0,2,false]} (String)
+# Parsed JSON:
+# Without addition: "0..2" (String)
+# With addition: 0..2 (Range)
+#
+# The \JSON module includes additions for certain classes.
+# You can also craft custom additions.
+# See {Custom \JSON Additions}[#module-JSON-label-Custom+JSON+Additions].
+#
+# === Built-in Additions
+#
+# The \JSON module includes additions for certain classes.
+# To use an addition, +require+ its source:
+# - BigDecimal: <tt>require 'json/add/bigdecimal'</tt>
+# - Complex: <tt>require 'json/add/complex'</tt>
+# - Date: <tt>require 'json/add/date'</tt>
+# - DateTime: <tt>require 'json/add/date_time'</tt>
+# - Exception: <tt>require 'json/add/exception'</tt>
+# - OpenStruct: <tt>require 'json/add/ostruct'</tt>
+# - Range: <tt>require 'json/add/range'</tt>
+# - Rational: <tt>require 'json/add/rational'</tt>
+# - Regexp: <tt>require 'json/add/regexp'</tt>
+# - Set: <tt>require 'json/add/set'</tt>
+# - Struct: <tt>require 'json/add/struct'</tt>
+# - Symbol: <tt>require 'json/add/symbol'</tt>
+# - Time: <tt>require 'json/add/time'</tt>
+#
+# To reduce punctuation clutter, the examples below
+# show the generated \JSON via +puts+, rather than the usual +inspect+,
+#
+# \BigDecimal:
+# require 'json/add/bigdecimal'
+# ruby0 = BigDecimal(0) # 0.0
+# json = JSON.generate(ruby0) # {"json_class":"BigDecimal","b":"27:0.0"}
+# ruby1 = JSON.parse(json, create_additions: true) # 0.0
+# ruby1.class # => BigDecimal
+#
+# \Complex:
+# require 'json/add/complex'
+# ruby0 = Complex(1+0i) # 1+0i
+# json = JSON.generate(ruby0) # {"json_class":"Complex","r":1,"i":0}
+# ruby1 = JSON.parse(json, create_additions: true) # 1+0i
+# ruby1.class # Complex
+#
+# \Date:
+# require 'json/add/date'
+# ruby0 = Date.today # 2020-05-02
+# json = JSON.generate(ruby0) # {"json_class":"Date","y":2020,"m":5,"d":2,"sg":2299161.0}
+# ruby1 = JSON.parse(json, create_additions: true) # 2020-05-02
+# ruby1.class # Date
+#
+# \DateTime:
+# require 'json/add/date_time'
+# ruby0 = DateTime.now # 2020-05-02T10:38:13-05:00
+# json = JSON.generate(ruby0) # {"json_class":"DateTime","y":2020,"m":5,"d":2,"H":10,"M":38,"S":13,"of":"-5/24","sg":2299161.0}
+# ruby1 = JSON.parse(json, create_additions: true) # 2020-05-02T10:38:13-05:00
+# ruby1.class # DateTime
+#
+# \Exception (and its subclasses including \RuntimeError):
+# require 'json/add/exception'
+# ruby0 = Exception.new('A message') # A message
+# json = JSON.generate(ruby0) # {"json_class":"Exception","m":"A message","b":null}
+# ruby1 = JSON.parse(json, create_additions: true) # A message
+# ruby1.class # Exception
+# ruby0 = RuntimeError.new('Another message') # Another message
+# json = JSON.generate(ruby0) # {"json_class":"RuntimeError","m":"Another message","b":null}
+# ruby1 = JSON.parse(json, create_additions: true) # Another message
+# ruby1.class # RuntimeError
+#
+# \OpenStruct:
+# require 'json/add/ostruct'
+# ruby0 = OpenStruct.new(name: 'Matz', language: 'Ruby') # #<OpenStruct name="Matz", language="Ruby">
+# json = JSON.generate(ruby0) # {"json_class":"OpenStruct","t":{"name":"Matz","language":"Ruby"}}
+# ruby1 = JSON.parse(json, create_additions: true) # #<OpenStruct name="Matz", language="Ruby">
+# ruby1.class # OpenStruct
+#
+# \Range:
+# require 'json/add/range'
+# ruby0 = Range.new(0, 2) # 0..2
+# json = JSON.generate(ruby0) # {"json_class":"Range","a":[0,2,false]}
+# ruby1 = JSON.parse(json, create_additions: true) # 0..2
+# ruby1.class # Range
+#
+# \Rational:
+# require 'json/add/rational'
+# ruby0 = Rational(1, 3) # 1/3
+# json = JSON.generate(ruby0) # {"json_class":"Rational","n":1,"d":3}
+# ruby1 = JSON.parse(json, create_additions: true) # 1/3
+# ruby1.class # Rational
+#
+# \Regexp:
+# require 'json/add/regexp'
+# ruby0 = Regexp.new('foo') # (?-mix:foo)
+# json = JSON.generate(ruby0) # {"json_class":"Regexp","o":0,"s":"foo"}
+# ruby1 = JSON.parse(json, create_additions: true) # (?-mix:foo)
+# ruby1.class # Regexp
+#
+# \Set:
+# require 'json/add/set'
+# ruby0 = Set.new([0, 1, 2]) # #<Set: {0, 1, 2}>
+# json = JSON.generate(ruby0) # {"json_class":"Set","a":[0,1,2]}
+# ruby1 = JSON.parse(json, create_additions: true) # #<Set: {0, 1, 2}>
+# ruby1.class # Set
+#
+# \Struct:
+# require 'json/add/struct'
+# Customer = Struct.new(:name, :address) # Customer
+# ruby0 = Customer.new("Dave", "123 Main") # #<struct Customer name="Dave", address="123 Main">
+# json = JSON.generate(ruby0) # {"json_class":"Customer","v":["Dave","123 Main"]}
+# ruby1 = JSON.parse(json, create_additions: true) # #<struct Customer name="Dave", address="123 Main">
+# ruby1.class # Customer
+ #
+# \Symbol:
+# require 'json/add/symbol'
+# ruby0 = :foo # foo
+# json = JSON.generate(ruby0) # {"json_class":"Symbol","s":"foo"}
+# ruby1 = JSON.parse(json, create_additions: true) # foo
+# ruby1.class # Symbol
+#
+# \Time:
+# require 'json/add/time'
+# ruby0 = Time.now # 2020-05-02 11:28:26 -0500
+# json = JSON.generate(ruby0) # {"json_class":"Time","s":1588436906,"n":840560000}
+# ruby1 = JSON.parse(json, create_additions: true) # 2020-05-02 11:28:26 -0500
+# ruby1.class # Time
+#
+#
+# === Custom \JSON Additions
+#
+# In addition to the \JSON additions provided,
+# you can craft \JSON additions of your own,
+# either for Ruby built-in classes or for user-defined classes.
+#
+# Here's a user-defined class +Foo+:
+# class Foo
+# attr_accessor :bar, :baz
+# def initialize(bar, baz)
+# self.bar = bar
+# self.baz = baz
+# end
+# end
+#
+# Here's the \JSON addition for it:
+# # Extend class Foo with JSON addition.
+# class Foo
+# # Serialize Foo object with its class name and arguments
+# def to_json(*args)
+# {
+# JSON.create_id => self.class.name,
+# 'a' => [ bar, baz ]
+# }.to_json(*args)
+# end
+# # Deserialize JSON string by constructing new Foo object with arguments.
+# def self.json_create(object)
+# new(*object['a'])
+# end
+# end
+#
+# Demonstration:
# require 'json'
+# # This Foo object has no custom addition.
+# foo0 = Foo.new(0, 1)
+# json0 = JSON.generate(foo0)
+# obj0 = JSON.parse(json0)
+# # Lood the custom addition.
+# require_relative 'foo_addition'
+# # This foo has the custom addition.
+# foo1 = Foo.new(0, 1)
+# json1 = JSON.generate(foo1)
+# obj1 = JSON.parse(json1, create_additions: true)
+# # Make a nice display.
+# display = <<EOT
+# Generated JSON:
+# Without custom addition: #{json0} (#{json0.class})
+# With custom addition: #{json1} (#{json1.class})
+# Parsed JSON:
+# Without custom addition: #{obj0.inspect} (#{obj0.class})
+# With custom addition: #{obj1.inspect} (#{obj1.class})
+# EOT
+# puts display
+#
+# Output:
+#
+# Generated JSON:
+# Without custom addition: "#<Foo:0x0000000006534e80>" (String)
+# With custom addition: {"json_class":"Foo","a":[0,1]} (String)
+# Parsed JSON:
+# Without custom addition: "#<Foo:0x0000000006534e80>" (String)
+# With custom addition: #<Foo:0x0000000006473bb8 @bar=0, @baz=1> (Foo)
#
-# 1.to_json # => "1"
-#
-# The {#generate}[rdoc-ref:JSON#generate] method accepts a variety of options
-# to set the formatting of string output and defining what input is accepteable.
-# There are also shortcut methods pretty_generate (with a set of options to
-# generate human-readable multiline JSON) and fast_generate (with a set of
-# options to generate JSON faster at the price of disabling some checks).
-#
-# == Extended rendering and loading of Ruby objects
-#
-# JSON library provides optional _additions_ allowing to serialize and
-# deserialize Ruby classes without loosing their type.
-#
-# # without additions
-# require "json"
-# json = JSON.generate({range: 1..3, regex: /test/})
-# # => '{"range":"1..3","regex":"(?-mix:test)"}'
-# JSON.parse(json)
-# # => {"range"=>"1..3", "regex"=>"(?-mix:test)"}
-#
-# # with additions
-# require "json/add/range"
-# require "json/add/regexp"
-# json = JSON.generate({range: 1..3, regex: /test/})
-# # => '{"range":{"json_class":"Range","a":[1,3,false]},"regex":{"json_class":"Regexp","o":0,"s":"test"}}'
-# JSON.parse(json)
-# # => {"range"=>{"json_class"=>"Range", "a"=>[1, 3, false]}, "regex"=>{"json_class"=>"Regexp", "o"=>0, "s"=>"test"}}
-# JSON.load(json)
-# # => {"range"=>1..3, "regex"=>/test/}
-#
-# See JSON.load for details.
module JSON
require 'json/version'