# frozen_string_literal: true
require 'psych/versions'
case RUBY_ENGINE
when 'jruby'
require 'psych_jars'
if JRuby::Util.respond_to?(:load_ext)
JRuby::Util.load_ext('org.jruby.ext.psych.PsychLibrary')
else
require 'java'; require 'jruby'
org.jruby.ext.psych.PsychLibrary.new.load(JRuby.runtime, false)
end
else
begin
require "#{RUBY_VERSION[/\d+\.\d+/]}/psych.so"
rescue LoadError
require 'psych.so'
end
end
require 'psych/nodes'
require 'psych/streaming'
require 'psych/visitors'
require 'psych/handler'
require 'psych/tree_builder'
require 'psych/parser'
require 'psych/omap'
require 'psych/set'
require 'psych/coder'
require 'psych/core_ext'
require 'psych/stream'
require 'psych/json/tree_builder'
require 'psych/json/stream'
require 'psych/handlers/document_stream'
require 'psych/class_loader'
###
# = Overview
#
# Psych is a YAML parser and emitter.
# Psych leverages libyaml [Home page: https://pyyaml.org/wiki/LibYAML]
# or [HG repo: https://bitbucket.org/xi/libyaml] for its YAML parsing
# and emitting capabilities. In addition to wrapping libyaml, Psych also
# knows how to serialize and de-serialize most Ruby objects to and from
# the YAML format.
#
# = I NEED TO PARSE OR EMIT YAML RIGHT NOW!
#
# # Parse some YAML
# Psych.load("--- foo") # => "foo"
#
# # Emit some YAML
# Psych.dump("foo") # => "--- foo\n...\n"
# { :a => 'b'}.to_yaml # => "---\n:a: b\n"
#
# Got more time on your hands? Keep on reading!
#
# == YAML Parsing
#
# Psych provides a range of interfaces for parsing a YAML document ranging from
# low level to high level, depending on your parsing needs. At the lowest
# level, is an event based parser. Mid level is access to the raw YAML AST,
# and at the highest level is the ability to unmarshal YAML to Ruby objects.
#
# == YAML Emitting
#
# Psych provides a range of interfaces ranging from low to high level for
# producing YAML documents. Very similar to the YAML parsing interfaces, Psych
# provides at the lowest level, an event based system, mid-level is building
# a YAML AST, and the highest level is converting a Ruby object straight to
# a YAML document.
#
# == High-level API
#
# === Parsing
#
# The high level YAML parser provided by Psych simply takes YAML as input and
# returns a Ruby data structure. For information on using the high level parser
# see Psych.load
#
# ==== Reading from a string
#
# Psych.load("--- a") # => 'a'
# Psych.load("---\n - a\n - b") # => ['a', 'b']
#
# ==== Reading from a file
#
# Psych.load_file("database.yml")
#
# ==== Exception handling
#
# begin
# # The second argument changes only the exception contents
# Psych.parse("--- `", "file.txt")
# rescue Psych::SyntaxError => ex
# ex.file # => 'file.txt'
# ex.message # => "(file.txt): found character that cannot start any token"
# end
#
# === Emitting
#
# The high level emitter has the easiest interface. Psych simply takes a Ruby
# data structure and converts it to a YAML document. See Psych.dump for more
# information on dumping a Ruby data structure.
#
# ==== Writing to a string
#
# # Dump an array, get back a YAML string
# Psych.dump(['a', 'b']) # => "---\n- a\n- b\n"
#
# # Dump an array to an IO object
# Psych.dump(['a', 'b'], StringIO.new) # => #<StringIO:0x000001009d0890>
#
# # Dump an array with indentation set
# Psych.dump(['a', ['b']], :indentation => 3) # => "---\n- a\n- - b\n"
#
# # Dump an array to an IO with indentation set
# Psych.dump(['a', ['b']], StringIO.new, :indentation => 3)
#
# ==== Writing to a file
#
# Currently there is no direct API for dumping Ruby structure to file:
#
# File.open('database.yml', 'w') do |file|
# file.write(Psych.dump(['a', 'b']))
# end
#
# == Mid-level API
#
# === Parsing
#
# Psych provides access to an AST produced from parsing a YAML document. This
# tree is built using the Psych::Parser and Psych::TreeBuilder. The AST can
# be examined and manipulated freely. Please see Psych::parse_stream,
# Psych::Nodes, and Psych::Nodes::Node for more information on dealing with
# YAML syntax trees.
#
# ==== Reading from a string
#
# # Returns Psych::Nodes::Stream
# Psych.parse_stream("---\n - a\n - b")
#
# # Returns Psych::Nodes::Document
# Psych.parse("---\n - a\n - b")
#
# ==== Reading from a file
#
# # Returns Psych::Nodes::Stream
# Psych.parse_stream(File.read('database.yml'))
#
# # Returns Psych::Nodes::Document
# Psych.parse_file('database.yml')
#
# ==== Exception handling
#
# begin
# # The second argument changes only the exception contents
# Psych.parse("--- `", "file.txt")
# rescue Psych::SyntaxError => ex
# ex.file # => 'file.txt'
# ex.message # => "(file.txt): found character that cannot start any token"
# end
#
# === Emitting
#
# At the mid level is building an AST. This AST is exactly the same as the AST
# used when parsing a YAML document. Users can build an AST by hand and the
# AST knows how to emit itself as a YAML document. See Psych::Nodes,
# Psych::Nodes::Node, and Psych::TreeBuilder for more information on building
# a YAML AST.
#
# ==== Writing to a string
#
# # We need Psych::Nodes::Stream (not Psych::Nodes::Document)
# stream = Psych.parse_stream("---\n - a\n - b")
#
# stream.to_yaml # => "---\n- a\n- b\n"
#
# ==== Writing to a file
#
# # We need Psych::Nodes::Stream (not Psych::Nodes::Document)
# stream = Psych.parse_stream(File.read('database.yml'))
#
# File.open('database.yml', 'w') do |file|
# file.write(stream.to_yaml)
# end
#
# == Low-level API
#
# === Parsing
#
# The lowest level parser should be used when the YAML input is already known,
# and the developer does not want to pay the price of building an AST or
# automatic detection and conversion to Ruby objects. See Psych::Parser for
# more information on using the event based parser.
#
# ==== Reading to Psych::Nodes::Stream structure
#
# parser = Psych::Parser.new(TreeBuilder.new) # => #<Psych::Parser>
# parser = Psych.parser # it's an alias for the above
#
# parser.parse("---\n - a\n - b") # => #<Psych::Parser>
# parser.handler # => #<Psych::TreeBuilder>
# parser.handler.root # => #<Psych::Nodes::Stream>
#
# ==== Receiving an events stream
#
# recorder = Psych::Handlers::Recorder.new
# parser = Psych::Parser.new(recorder)
#
# parser.parse("---\n - a\n - b")
# recorder.events # => [list of [event, args] lists]
# # event is one of: Psych::Handler::EVENTS
# # args are the arguments passed to the event
#
# === Emitting
#
# The lowest level emitter is an event based system. Events are sent to a
# Psych::Emitter object. That object knows how to convert the events to a YAML
# document. This interface should be used when document format is known in
# advance or speed is a concern. See Psych::Emitter for more information.
#
# ==== Writing to a Ruby structure
#
# Psych.parser.parse("--- a") # => #<Psych::Parser>
#
# parser.handler.first # => #<Psych::Nodes::Stream>
# parser.handler.first.to_ruby # => ["a"]
#
# parser.handler.root.first # => #<Psych::Nodes::Document>
# parser.handler.root.first.to_ruby # => "a"
#
# # You can instantiate an Emitter manually
# Psych::Visitors::ToRuby.new.accept(parser.handler.root.first)
# # => "a"
module Psych
# The version of libyaml Psych is using
LIBYAML_VERSION = Psych.libyaml_version.join '.'
# Deprecation guard
NOT_GIVEN = Object.new
private_constant :NOT_GIVEN
###
# Load +yaml+ in to a Ruby data structure. If multiple documents are
# provided, the object contained in the first document will be returned.
# +filename+ will be used in the exception message if any exception
# is raised while parsing. If +yaml+ is empty, it returns
# the specified +fallback+ return value, which defaults to +false+.
#
# Raises a Psych::SyntaxError when a YAML syntax error is detected.
#
# Example:
#
# Psych.load("--- a") # => 'a'
# Psych.load("---\n - a\n - b") # => ['a', 'b']
#
# begin
# Psych.load("--- `", filename: "file.txt")
# rescue Psych::SyntaxError => ex
# ex.file # => 'file.txt'
# ex.message # => "(file.txt): found character that cannot start any token"
# end
#
# When the optional +symbolize_names+ keyword argument is set to a
# true value, returns symbols for keys in Hash objects (default: strings).
#
# Psych.load("---\n foo: bar") # => {"foo"=>"bar"}
# Psych.load("---\n foo: bar", symbolize_names: true) # => {:foo=>"bar"}
#
# Raises a TypeError when `yaml` parameter is NilClass
#
def self.load yaml, legacy_filename = NOT_GIVEN, filename: nil, fallback: false, symbolize_names: false
if legacy_filename != NOT_GIVEN
warn_with_uplevel 'Passing filename with the 2nd argument of Psych.load is deprecated. Use keyword argument like Psych.load(yaml, filename: ...) instead.', uplevel: 1 if $VERBOSE
filename = legacy_filename
end
result = parse(yaml, filename: filename)
return fallback unless result
result = result.to_ruby if result
symbolize_names!(result) if symbolize_names
result
end
###
# Safely load the yaml string in +yaml+. By default, only the following
# classes are allowed to be deserialized:
#
# * TrueClass
# * FalseClass
# * NilClass
# * Numeric
# * String
# * Array
# * Hash
#
# Recursive data structures are not allowed by default. Arbitrary classes
# can be allowed by adding those classes to the +permitted_classes+ keyword argument. They are
# additive. For example, to allow Date deserialization:
#
# Psych.safe_load(yaml, permitted_classes: [Date])
#
# Now the Date class can be loaded in addition to the classes listed above.
#
# Aliases can be explicitly allowed by changing the +aliases+ keyword argument.
# For example:
#
# x = []
# x << x
# yaml = Psych.dump x
# Psych.safe_load yaml # => raises an exception
# Psych.safe_load yaml, aliases: true # => loads the aliases
#
# A Psych::DisallowedClass exception will be raised if the yaml contains a
# class that isn't in the +permitted_classes+ list.
#
# A Psych::BadAlias exception will be raised if the yaml contains aliases
# but the +aliases+ keyword argument is set to false.
#
# +filename+ will be used in the exception message if any exception is raised
# while parsing.
#
# When the optional +symbolize_names+ keyword argument is set to a
# true value, returns symbols for keys in Hash objects (default: strings).
#
# Psych.safe_load("---\n foo: bar") # => {"foo"=>"bar"}
# Psych.safe_load("---\n foo: bar", symbolize_names: true) # => {:foo=>"bar"}
#
def self.safe_load yaml, legacy_permitted_classes = NOT_GIVEN, legacy_permitted_symbols = NOT_GIVEN, legacy_aliases = NOT_GIVEN, legacy_filename = NOT_GIVEN, permitted_classes: [], permitted_symbols: [], aliases: false, filename: nil, fallback: nil, symbolize_names: false
if legacy_permitted_classes != NOT_GIVEN
warn_with_uplevel 'Passing permitted_classes with the 2nd argument of Psych.safe_load is deprecated. Use keyword argument like Psych.safe_load(yaml, permitted_classes: ...) instead.', uplevel: 1 if $VERBOSE
permitted_classes = legacy_permitted_classes
end
if legacy_permitted_symbols != NOT_GIVEN
warn_with_uplevel 'Passing permitted_symbols with the 3rd argument of Psych.safe_load is deprecated. Use keyword argument like Psych.safe_load(yaml, permitted_symbols: ...) instead.', uplevel: 1 if $VERBOSE
permitted_symbols = legacy_permitted_symbols
end
if legacy_aliases != NOT_GIVEN
warn_with_uplevel 'Passing aliases with the 4th argument of Psych.safe_load is deprecated. Use keyword argument like Psych.safe_load(yaml, aliases: ...) instead.', uplevel: 1 if $VERBOSE
aliases = legacy_aliases
end
if legacy_filename != NOT_GIVEN
warn_with_uplevel 'Passing filename with the 5th argument of Psych.safe_load is deprecated. Use keyword argument like Psych.safe_load(yaml, filename: ...) instead.', uplevel: 1 if $VERBOSE
filename = legacy_filename
end
result = parse(yaml, filename: filename)
return fallback unless result
class_loader = ClassLoader::Restricted.new(permitted_classes.map(&:to_s),
permitted_symbols.map(&:to_s))
scanner = ScalarScanner.new class_loader
visitor = if aliases
Visitors::ToRuby.new scanner, class_loader
else
Visitors::NoAliasRuby.new scanner, class_loader
end
result = visitor.accept result
symbolize_names!(result) if symbolize_names
result
end
###
# Parse a YAML string in +yaml+. Returns the Psych::Nodes::Document.
# +filename+ is used in the exception message if a Psych::SyntaxError is
# raised.
#
# Raises a Psych::SyntaxError when a YAML syntax error is detected.
#
# Example:
#
# Psych.parse("---\n - a\n - b") # => #<Psych::Nodes::Document:0x00>
#
# begin
# Psych.parse("--- `", filename: "file.txt")
# rescue Psych::SyntaxError => ex
# ex.file # => 'file.txt'
# ex.message # => "(file.txt): found character that cannot start any token"
# end
#
# See Psych::Nodes for more information about YAML AST.
def self.parse yaml, legacy_filename = NOT_GIVEN, filename: nil, fallback: NOT_GIVEN
if legacy_filename != NOT_GIVEN
warn_with_uplevel 'Passing filename with the 2nd argument of Psych.parse is deprecated. Use keyword argument like Psych.parse(yaml, filename: ...) instead.', uplevel: 1 if $VERBOSE
filename = legacy_filename
end
parse_stream(yaml, filename: filename) do |node|
return node
end
if fallback != NOT_GIVEN
warn_with_uplevel 'Passing the `fallback` keyword argument of Psych.parse is deprecated.', uplevel: 1 if $VERBOSE
fallback
else
false
end
end
###
# Parse a file at +filename+. Returns the Psych::Nodes::Document.
#
# Raises a Psych::SyntaxError when a YAML syntax error is detected.
def self.parse_file filename, fallback: false
result = File.open filename, 'r:bom|utf-8' do |f|
parse f, filename: filename
end
result || fallback
end
###
# Returns a default parser
def self.parser
Psych::Parser.new(TreeBuilder.new)
end
###
# Parse a YAML string in +yaml+. Returns the Psych::Nodes::Stream.
# This method can handle multiple YAML documents contained in +yaml+.
# +filename+ is used in the exception message if a Psych::SyntaxError is
# raised.
#
# If a block is given, a Psych::Nodes::Document node will be yielded to the
# block as it's being parsed.
#
# Raises a Psych::SyntaxError when a YAML syntax error is detected.
#
# Example:
#
# Psych.parse_stream("---\n - a\n - b") # => #<Psych::Nodes::Stream:0x00>
#
# Psych.parse_stream("--- a\n--- b") do |node|
# node # => #<Psych::Nodes::Document:0x00>
# end
#
# begin
# Psych.parse_stream("--- `", filename: "file.txt")
# rescue Psych::SyntaxError => ex
# ex.file # => 'file.txt'
# ex.message # => "(file.txt): found character that cannot start any token"
# end
#
# Raises a TypeError when NilClass is passed.
#
# See Psych::Nodes for more information about YAML AST.
def self.parse_stream yaml, legacy_filename = NOT_GIVEN, filename: nil, &block
if legacy_filename != NOT_GIVEN
warn_with_uplevel 'Passing filename with the 2nd argument of Psych.parse_stream is deprecated. Use keyword argument like Psych.parse_stream(yaml, filename: ...) instead.', uplevel: 1 if $VERBOSE
filename = legacy_filename
end
if block_given?
parser = Psych::Parser.new(Handlers::DocumentStream.new(&block))
parser.parse yaml, filename
else
parser = self.parser
parser.parse yaml, filename
parser.handler.root
end
end
###
# call-seq:
# Psych.dump(o) -> string of yaml
# Psych.dump(o, options) -> string of yaml
# Psych.dump(o, io) -> io object passed in
# Psych.dump(o, io, options) -> io object passed in
#
# Dump Ruby object +o+ to a YAML string. Optional +options+ may be passed in
# to control the output format. If an IO object is passed in, the YAML will
# be dumped to that IO object.
#
# Currently supported options are:
#
# [<tt>:indentation</tt>] Number of space characters used to indent.
# Acceptable value should be in <tt>0..9</tt> range,
# otherwise option is ignored.
#
# Default: <tt>2</tt>.
# [<tt>:line_width</tt>] Max character to wrap line at.
#
# Default: <tt>0</tt> (meaning "wrap at 81").
# [<tt>:canonical</tt>] Write "canonical" YAML form (very verbose, yet
# strictly formal).
#
# Default: <tt>false</tt>.
# [<tt>:header</tt>] Write <tt>%YAML [version]</tt> at the beginning of document.
#
# Default: <tt>false</tt>.
#
# Example:
#
# # Dump an array, get back a YAML string
# Psych.dump(['a', 'b']) # => "---\n- a\n- b\n"
#
# # Dump an array to an IO object
# Psych.dump(['a', 'b'], StringIO.new) # => #<StringIO:0x000001009d0890>
#
# # Dump an array with indentation set
# Psych.dump(['a', ['b']], indentation: 3) # => "---\n- a\n- - b\n"
#
# # Dump an array to an IO with indentation set
# Psych.dump(['a', ['b']], StringIO.new, indentation: 3)
def self.dump o, io = nil, options = {}
if Hash === io
options = io
io = nil
end
visitor = Psych::Visitors::YAMLTree.create options
visitor << o
visitor.tree.yaml io, options
end
###
# Dump a list of objects as separate documents to a document stream.
#
# Example:
#
# Psych.dump_stream("foo\n ", {}) # => "--- ! \"foo\\n \"\n--- {}\n"
def self.dump_stream *objects
visitor = Psych::Visitors::YAMLTree.create({})
objects.each do |o|
visitor << o
end
visitor.tree.yaml
end
###
# Dump Ruby +object+ to a JSON string.
def self.to_json object
visitor = Psych::Visitors::JSONTree.create
visitor << object
visitor.tree.yaml
end
###
# Load multiple documents given in +yaml+. Returns the parsed documents
# as a list. If a block is given, each document will be converted to Ruby
# and passed to the block during parsing
#
# Example:
#
# Psych.load_stream("--- foo\n...\n--- bar\n...") # => ['foo', 'bar']
#
# list = []
# Psych.load_stream("--- foo\n...\n--- bar\n...") do |ruby|
# list << ruby
# end
# list # => ['foo', 'bar']
#
def self.load_stream yaml, legacy_filename = NOT_GIVEN, filename: nil, fallback: []
if legacy_filename != NOT_GIVEN
warn_with_uplevel 'Passing filename with the 2nd argument of Psych.load_stream is deprecated. Use keyword argument like Psych.load_stream(yaml, filename: ...) instead.', uplevel: 1 if $VERBOSE
filename = legacy_filename
end
result = if block_given?
parse_stream(yaml, filename: filename) do |node|
yield node.to_ruby
end
else
parse_stream(yaml, filename: filename).children.map(&:to_ruby)
end
return fallback if result.is_a?(Array) && result.empty?
result
end
###
# Load the document contained in +filename+. Returns the yaml contained in
# +filename+ as a Ruby object, or if the file is empty, it returns
# the specified +fallback+ return value, which defaults to +false+.
def self.load_file filename, fallback: false
File.open(filename, 'r:bom|utf-8') { |f|
self.load f, filename: filename, fallback: fallback
}
end
# :stopdoc:
@domain_types = {}
def self.add_domain_type domain, type_tag, &block
key = ['tag', domain, type_tag].join ':'
@domain_types[key] = [key, block]
@domain_types["tag:#{type_tag}"] = [key, block]
end
def self.add_builtin_type type_tag, &block
domain = 'yaml.org,2002'
key = ['tag', domain, type_tag].join ':'
@domain_types[key] = [key, block]
end
def self.remove_type type_tag
@domain_types.delete type_tag
end
@load_tags = {}
@dump_tags = {}
def self.add_tag tag, klass
@load_tags[tag] = klass.name
@dump_tags[klass] = tag
end
def self.symbolize_names!(result)
case result
when Hash
result.keys.each do |key|
result[key.to_sym] = symbolize_names!(result.delete(key))
end
when Array
result.map! { |r| symbolize_names!(r) }
end
result
end
private_class_method :symbolize_names!
# Workaround for emulating `warn '...', uplevel: 1` in Ruby 2.4 or lower.
def self.warn_with_uplevel(message, uplevel: 1)
at = parse_caller(caller[uplevel]).join(':')
warn "#{at}: #{message}"
end
def self.parse_caller(at)
if /^(.+?):(\d+)(?::in `.*')?/ =~ at
file = $1
line = $2.to_i
[file, line]
end
end
private_class_method :warn_with_uplevel, :parse_caller
class << self
attr_accessor :load_tags
attr_accessor :dump_tags
attr_accessor :domain_types
end
# :startdoc:
end