| Current File : //opt/alt/ruby30/share/ruby/json.rb |
#frozen_string_literal: false
require 'json/common'
##
# = JavaScript \Object Notation (\JSON)
#
# \JSON is a lightweight data-interchange format.
#
# 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]
#
# - \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}
#
# 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]]
#
# == Using \Module \JSON
#
# To make module \JSON available in your code, begin with:
# require 'json'
#
# All examples here assume that this has been done.
#
# === Parsing \JSON
#
# 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>
#
# where
# - +source+ is a Ruby object.
# - +opts+ is a \Hash object containing options
# that control both input allowed and output formatting.
#
# 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.
#
# ==== Parsing \JSON Arrays
#
# 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
#
# 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]]
#
# ==== 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
#
# ==== Parsing Options
#
# ====== Input Options
#
# Option +max_nesting+ (\Integer) specifies the maximum nesting depth allowed;
# defaults to +100+; specify +false+ to disable depth checking.
#
# With the default, +false+:
# source = '[0, [1, [2, [3]]]]'
# ruby = JSON.parse(source)
# ruby # => [0, [1, [2, [3]]]]
# Too deep:
# # Raises JSON::NestingError (nesting of 2 is too deep):
# JSON.parse(source, {max_nesting: 1})
# Bad value:
# # Raises TypeError (wrong argument type Symbol (expected Fixnum)):
# JSON.parse(source, {max_nesting: :foo})
#
# ---
#
# Option +allow_nan+ (boolean) specifies whether to allow
# NaN, Infinity, and MinusInfinity in +source+;
# defaults to +false+.
#
# With the default, +false+:
# # Raises JSON::ParserError (225: unexpected token at '[NaN]'):
# JSON.parse('[NaN]')
# # Raises JSON::ParserError (232: unexpected token at '[Infinity]'):
# JSON.parse('[Infinity]')
# # Raises JSON::ParserError (248: unexpected token at '[-Infinity]'):
# JSON.parse('[-Infinity]')
# Allow:
# source = '[NaN, Infinity, -Infinity]'
# ruby = JSON.parse(source, {allow_nan: true})
# ruby # => [NaN, Infinity, -Infinity]
#
# ====== Output Options
#
# Option +symbolize_names+ (boolean) specifies whether returned \Hash keys
# should be Symbols;
# defaults to +false+ (use Strings).
#
# With the default, +false+:
# source = '{"a": "foo", "b": 1.0, "c": true, "d": false, "e": null}'
# ruby = JSON.parse(source)
# ruby # => {"a"=>"foo", "b"=>1.0, "c"=>true, "d"=>false, "e"=>nil}
# Use Symbols:
# ruby = JSON.parse(source, {symbolize_names: true})
# ruby # => {:a=>"foo", :b=>1.0, :c=>true, :d=>false, :e=>nil}
#
# ---
#
# Option +object_class+ (\Class) specifies the Ruby class to be used
# for each \JSON object;
# defaults to \Hash.
#
# With the default, \Hash:
# source = '{"a": "foo", "b": 1.0, "c": true, "d": false, "e": null}'
# ruby = JSON.parse(source)
# ruby.class # => Hash
# Use class \OpenStruct:
# ruby = JSON.parse(source, {object_class: OpenStruct})
# ruby # => #<OpenStruct a="foo", b=1.0, c=true, d=false, e=nil>
#
# ---
#
# Option +array_class+ (\Class) specifies the Ruby class to be used
# for each \JSON array;
# defaults to \Array.
#
# With the default, \Array:
# source = '["foo", 1.0, true, false, null]'
# ruby = JSON.parse(source)
# ruby.class # => Array
# Use class \Set:
# ruby = JSON.parse(source, {array_class: Set})
# ruby # => #<Set: {"foo", 1.0, true, false, nil}>
#
# ---
#
# Option +create_additions+ (boolean) specifies whether to use \JSON additions in parsing.
# See {\JSON Additions}[#module-JSON-label-JSON+Additions].
#
# === 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(42) # => '42'
# JSON.generate(0.42) # => '0.42'
#
# 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>"'
#
# ==== Generating Options
#
# ====== Input Options
#
# Option +allow_nan+ (boolean) specifies whether
# +NaN+, +Infinity+, and <tt>-Infinity</tt> may be generated;
# defaults to +false+.
#
# With the default, +false+:
# # Raises JSON::GeneratorError (920: NaN not allowed in JSON):
# JSON.generate(JSON::NaN)
# # Raises JSON::GeneratorError (917: Infinity not allowed in JSON):
# JSON.generate(JSON::Infinity)
# # Raises JSON::GeneratorError (917: -Infinity not allowed in JSON):
# JSON.generate(JSON::MinusInfinity)
#
# Allow:
# ruby = [Float::NaN, Float::Infinity, Float::MinusInfinity]
# JSON.generate(ruby, allow_nan: true) # => '[NaN,Infinity,-Infinity]'
#
# ---
#
# Option +max_nesting+ (\Integer) specifies the maximum nesting depth
# in +obj+; defaults to +100+.
#
# With the default, +100+:
# obj = [[[[[[0]]]]]]
# JSON.generate(obj) # => '[[[[[[0]]]]]]'
#
# Too deep:
# # Raises JSON::NestingError (nesting of 2 is too deep):
# JSON.generate(obj, max_nesting: 2)
#
# ====== Output Options
#
# The default formatting options generate the most compact
# \JSON data, all on one line and with no whitespace.
#
# You can use these formatting options to generate
# \JSON data in a more open format, using whitespace.
# See also JSON.pretty_generate.
#
# - Option +array_nl+ (\String) specifies a string (usually a newline)
# to be inserted after each \JSON array; defaults to the empty \String, <tt>''</tt>.
# - Option +object_nl+ (\String) specifies a string (usually a newline)
# to be inserted after each \JSON object; defaults to the empty \String, <tt>''</tt>.
# - Option +indent+ (\String) specifies the string (usually spaces) to be
# used for indentation; defaults to the empty \String, <tt>''</tt>;
# defaults to the empty \String, <tt>''</tt>;
# has no effect unless options +array_nl+ or +object_nl+ specify newlines.
# - Option +space+ (\String) specifies a string (usually a space) to be
# inserted after the colon in each \JSON object's pair;
# defaults to the empty \String, <tt>''</tt>.
# - Option +space_before+ (\String) specifies a string (usually a space) to be
# inserted before the colon in each \JSON object's pair;
# defaults to the empty \String, <tt>''</tt>.
#
# In this example, +obj+ is used first to generate the shortest
# \JSON data (no whitespace), then again with all formatting options
# specified:
#
# obj = {foo: [:bar, :baz], bat: {bam: 0, bad: 1}}
# json = JSON.generate(obj)
# puts 'Compact:', json
# opts = {
# array_nl: "\n",
# object_nl: "\n",
# indent: ' ',
# space_before: ' ',
# space: ' '
# }
# puts 'Open:', JSON.generate(obj, opts)
#
# Output:
# Compact:
# {"foo":["bar","baz"],"bat":{"bam":0,"bad":1}}
# Open:
# {
# "foo" : [
# "bar",
# "baz"
# ],
# "bat" : {
# "bam" : 0,
# "bad" : 1
# }
# }
#
# == \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.
#
# 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)
#
module JSON
require 'json/version'
begin
require 'json/ext'
rescue LoadError
require 'json/pure'
end
end