YAMLTree builds a YAML ast given a ruby object. For example:

builder = Psych::Visitors::YAMLTree.new
builder << { :foo => 'bar' }
builder.tree # => #<Psych::Nodes::Stream .. }
Methods
#
A
B
D
E
F
N
P
R
S
T
V
Attributes
[R] finished
[R] finished?
[R] started
[R] started?
Class Public methods
new(options = {})

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 15
def initialize options = {}, emitter = TreeBuilder.new, ss = ScalarScanner.new
  super()
  @started  = false
  @finished = false
  @emitter  = emitter
  @st       = {}
  @ss       = ss
  @options  = options
  @coders   = []

  @dispatch_cache = Hash.new do |h,klass|
    method = "visit_#{(klass.name || '').split('::').join('_')}"

    method = respond_to?(method) ? method : h[klass.superclass]

    raise(TypeError, "Can't dump #{target.class}") unless method

    h[klass] = method
  end
end
Instance Public methods
<<(object)
Alias for: push
accept(target)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 72
def accept target
  # return any aliases we find
  if @st.key? target.object_id
    oid         = target.object_id
    node        = @st[oid]
    anchor      = oid.to_s
    node.anchor = anchor
    return @emitter.alias anchor
  end

  if target.respond_to?(:to_yaml)
    begin
      loc = target.method(:to_yaml).source_location.first
      if loc !~ /(syck\/rubytypes.rb|psych\/core_ext.rb)/
        unless target.respond_to?(:encode_with)
          if $VERBOSE
            warn "implementing to_yaml is deprecated, please implement \"encode_with\""
          end

          target.to_yaml(:nodump => true)
        end
      end
    rescue
      # public_method or source_location might be overridden,
      # and it's OK to skip it since it's only to emit a warning
    end
  end

  if target.respond_to?(:encode_with)
    dump_coder target
  else
    send(@dispatch_cache[target.class], target)
  end
end
finish()

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 42
def finish
  @emitter.end_stream.tap do
    @finished = true
  end
end
push(object)
Also aliased as: <<

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 52
def push object
  start unless started?
  version = []
  version = [1,1] if @options[:header]

  case @options[:version]
  when Array
    version = @options[:version]
  when String
    version = @options[:version].split('.').map { |x| x.to_i }
  else
    version = [1,1]
  end if @options.key? :version

  @emitter.start_document version, [], false
  accept object
  @emitter.end_document
end
start(encoding = Nodes::Stream::UTF8)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 36
def start encoding = Nodes::Stream::UTF8
  @emitter.start_stream(encoding).tap do
    @started = true
  end
end
tree()

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 48
def tree
  finish unless finished?
end
visit_Array(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 310
def visit_Array o
  if o.class == ::Array
    register o, @emitter.start_sequence(nil, nil, true, Nodes::Sequence::BLOCK)
    o.each { |c| accept c }
    @emitter.end_sequence
  else
    visit_array_subclass o
  end
end
visit_BigDecimal(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 218
def visit_BigDecimal o
  @emitter.scalar o._dump, nil, '!ruby/object:BigDecimal', false, false, Nodes::Scalar::ANY
end
visit_Class(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 272
def visit_Class o
  raise TypeError, "can't dump anonymous class: #{o}" unless o.name
  register o, @emitter.scalar(o.name, nil, '!ruby/class', false, false, Nodes::Scalar::SINGLE_QUOTED)
end
visit_Complex(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 190
def visit_Complex o
  register o, @emitter.start_mapping(nil, '!ruby/object:Complex', false, Nodes::Mapping::BLOCK)

  ['real', o.real.to_s, 'image', o.imag.to_s].each do |m|
    @emitter.scalar m, nil, nil, true, false, Nodes::Scalar::ANY
  end

  @emitter.end_mapping
end
visit_Date(o)
Alias for: visit_Integer
visit_DateTime(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 166
def visit_DateTime o
  formatted = format_time o.to_time
  tag = '!ruby/object:DateTime'
  register o, @emitter.scalar(formatted, nil, tag, false, false, Nodes::Scalar::ANY)
end
visit_Exception(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 143
def visit_Exception o
  tag = ['!ruby/exception', o.class.name].join ':'

  @emitter.start_mapping nil, tag, false, Nodes::Mapping::BLOCK

  {
    'message'   => private_iv_get(o, 'mesg'),
    'backtrace' => private_iv_get(o, 'backtrace'),
  }.each do |k,v|
    next unless v
    @emitter.scalar k, nil, nil, true, false, Nodes::Scalar::ANY
    accept v
  end

  dump_ivars o

  @emitter.end_mapping
end
visit_FalseClass(o)
Alias for: visit_Integer
visit_Float(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 207
def visit_Float o
  if o.nan?
    @emitter.scalar '.nan', nil, nil, true, false, Nodes::Scalar::ANY
  elsif o.infinite?
    @emitter.scalar((o.infinite? > 0 ? '.inf' : '-.inf'),
      nil, nil, true, false, Nodes::Scalar::ANY)
  else
    @emitter.scalar o.to_s, nil, nil, true, false, Nodes::Scalar::ANY
  end
end
visit_Hash(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 285
def visit_Hash o
  tag      = o.class == ::Hash ? nil : "!ruby/hash:#{o.class}"
  implicit = !tag

  register(o, @emitter.start_mapping(nil, tag, implicit, Psych::Nodes::Mapping::BLOCK))

  o.each do |k,v|
    accept k
    accept v
  end

  @emitter.end_mapping
end
visit_Integer(o)
Also aliased as: visit_TrueClass, visit_FalseClass, visit_Date

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 200
def visit_Integer o
  @emitter.scalar o.to_s, nil, nil, true, false, Nodes::Scalar::ANY
end
visit_Module(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 267
def visit_Module o
  raise TypeError, "can't dump anonymous module: #{o}" unless o.name
  register o, @emitter.scalar(o.name, nil, '!ruby/module', false, false, Nodes::Scalar::SINGLE_QUOTED)
end
visit_NilClass(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 320
def visit_NilClass o
  @emitter.scalar('', nil, 'tag:yaml.org,2002:null', true, false, Nodes::Scalar::ANY)
end
visit_Object(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 115
def visit_Object o
  tag = Psych.dump_tags[o.class]
  unless tag
    klass = o.class == Object ? nil : o.class.name
    tag   = ['!ruby/object', klass].compact.join(':')
  end

  map = @emitter.start_mapping(nil, tag, false, Nodes::Mapping::BLOCK)
  register(o, map)

  dump_ivars o
  @emitter.end_mapping
end
visit_Psych_Omap(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 107
def visit_Psych_Omap o
  seq = @emitter.start_sequence(nil, '!omap', false, Nodes::Sequence::BLOCK)
  register(o, seq)

  o.each { |k,v| visit_Hash k => v }
  @emitter.end_sequence
end
visit_Psych_Set(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 299
def visit_Psych_Set o
  register(o, @emitter.start_mapping(nil, '!set', false, Psych::Nodes::Mapping::BLOCK))

  o.each do |k,v|
    accept k
    accept v
  end

  @emitter.end_mapping
end
visit_Range(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 277
def visit_Range o
  register o, @emitter.start_mapping(nil, '!ruby/range', false, Nodes::Mapping::BLOCK)
  ['begin', o.begin, 'end', o.end, 'excl', o.exclude_end?].each do |m|
    accept m
  end
  @emitter.end_mapping
end
visit_Rational(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 177
def visit_Rational o
  register o, @emitter.start_mapping(nil, '!ruby/object:Rational', false, Nodes::Mapping::BLOCK)

  [
    'denominator', o.denominator.to_s,
    'numerator', o.numerator.to_s
  ].each do |m|
    @emitter.scalar m, nil, nil, true, false, Nodes::Scalar::ANY
  end

  @emitter.end_mapping
end
visit_Regexp(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 162
def visit_Regexp o
  register o, @emitter.scalar(o.inspect, nil, '!ruby/regexp', false, false, Nodes::Scalar::ANY)
end
visit_String(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 229
def visit_String o
  plain = false
  quote = false
  style = Nodes::Scalar::ANY

  if binary?(o)
    str   = [o].pack('m').chomp
    tag   = '!binary' # FIXME: change to below when syck is removed
    #tag   = 'tag:yaml.org,2002:binary'
    style = Nodes::Scalar::LITERAL
  else
    str   = o
    tag   = nil
    quote = !(String === @ss.tokenize(o))
    plain = !quote
  end

  ivars = find_ivars o

  if ivars.empty?
    unless o.class == ::String
      tag = "!ruby/string:#{o.class}"
    end
    @emitter.scalar str, nil, tag, plain, quote, style
  else
    maptag = '!ruby/string'
    maptag << ":#{o.class}" unless o.class == ::String

    register o, @emitter.start_mapping(nil, maptag, false, Nodes::Mapping::BLOCK)
    @emitter.scalar 'str', nil, nil, true, false, Nodes::Scalar::ANY
    @emitter.scalar str, nil, tag, plain, quote, style

    dump_ivars o

    @emitter.end_mapping
  end
end
visit_Struct(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 129
def visit_Struct o
  tag = ['!ruby/struct', o.class.name].compact.join(':')

  register o, @emitter.start_mapping(nil, tag, false, Nodes::Mapping::BLOCK)
  o.members.each do |member|
    @emitter.scalar member.to_s, nil, nil, true, false, Nodes::Scalar::ANY
    accept o[member]
  end

  dump_ivars o

  @emitter.end_mapping
end
visit_Symbol(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 324
def visit_Symbol o
  @emitter.scalar ":#{o}", nil, nil, true, false, Nodes::Scalar::ANY
end
visit_Time(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 172
def visit_Time o
  formatted = format_time o
  @emitter.scalar formatted, nil, nil, true, false, Nodes::Scalar::ANY
end
visit_TrueClass(o)
Alias for: visit_Integer
Instance Private methods
binary?(string)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 222
def binary? string
  string.encoding == Encoding::ASCII_8BIT ||
    string.index("\x00") ||
    string.count("\x00-\x7F", "^ -~\t\r\n").fdiv(string.length) > 0.3
end
dump_coder(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 409
def dump_coder o
  @coders << o
  tag = Psych.dump_tags[o.class]
  unless tag
    klass = o.class == Object ? nil : o.class.name
    tag   = ['!ruby/object', klass].compact.join(':')
  end

  c = Psych::Coder.new(tag)
  o.encode_with(c)
  emit_coder c
end
dump_ivars(target)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 444
def dump_ivars target
  ivars = find_ivars target

  ivars.each do |iv|
    @emitter.scalar("#{iv.to_s.sub(/^@/, '')}", nil, nil, true, false, Nodes::Scalar::ANY)
    accept target.instance_variable_get(iv)
  end
end
dump_list(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 359
def dump_list o
end
emit_coder(c)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 422
def emit_coder c
  case c.type
  when :scalar
    @emitter.scalar c.scalar, nil, c.tag, c.tag.nil?, false, Nodes::Scalar::ANY
  when :seq
    @emitter.start_sequence nil, c.tag, c.tag.nil?, Nodes::Sequence::BLOCK
    c.seq.each do |thing|
      accept thing
    end
    @emitter.end_sequence
  when :map
    @emitter.start_mapping nil, c.tag, c.implicit, c.style
    c.map.each do |k,v|
      @emitter.scalar k, nil, nil, true, false, Nodes::Scalar::ANY
      accept v
    end
    @emitter.end_mapping
  when :object
    accept c.object
  end
end
find_ivars(target)

FIXME: remove this method once “to_yaml_properties” is removed

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 387
def find_ivars target
  begin
    loc = target.method(:to_yaml_properties).source_location.first
    unless loc.start_with?(Psych::DEPRECATED) || loc.end_with?('rubytypes.rb')
      if $VERBOSE
        warn "#{loc}: to_yaml_properties is deprecated, please implement \"encode_with(coder)\""
      end
      return target.to_yaml_properties
    end
  rescue
    # public_method or source_location might be overridden,
    # and it's OK to skip it since it's only to emit a warning.
  end

  target.instance_variables
end
format_time(time)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 364
def format_time time
  formatted = time.strftime("%Y-%m-%d %H:%M:%S.%9N")

  if time.utc?
    formatted += " Z"
  else
    zone = time.strftime('%z')
    formatted += " #{zone[0,3]}:#{zone[3,5]}"
  end

  formatted
end
private_iv_get(target, prop)

Get the private instance variable prop from target

Source: show 

static VALUE private_iv_get(VALUE self, VALUE target, VALUE prop)
{
    return rb_attr_get(target, rb_intern(StringValuePtr(prop)));
}
register(target, yaml_obj)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 404
def register target, yaml_obj
  @st[target.object_id] = yaml_obj
  yaml_obj
end
visit_array_subclass(o)

Source: show | on GitHub 

# File ../ruby/ext/psych/lib/psych/visitors/yaml_tree.rb, line 329
def visit_array_subclass o
  tag = "!ruby/array:#{o.class}"
  if o.instance_variables.empty?
    node = @emitter.start_sequence(nil, tag, false, Nodes::Sequence::BLOCK)
    register o, node
    o.each { |c| accept c }
    @emitter.end_sequence
  else
    node = @emitter.start_mapping(nil, tag, false, Nodes::Sequence::BLOCK)
    register o, node

    # Dump the internal list
    accept 'internal'
    @emitter.start_sequence(nil, nil, true, Nodes::Sequence::BLOCK)
    o.each { |c| accept c }
    @emitter.end_sequence

    # Dump the ivars
    accept 'ivars'
    @emitter.start_mapping(nil, nil, true, Nodes::Sequence::BLOCK)
    o.instance_variables.each do |ivar|
      accept ivar
      accept o.instance_variable_get ivar
    end
    @emitter.end_mapping

    @emitter.end_mapping
  end
end