Class: Psych::Visitors::YAMLTree

Inherits:
Visitor show all
Defined in:
lib/psych/visitors/yaml_tree.rb,
ext/psych/psych_yaml_tree.c

Overview

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

builder = Psych::Visitors::YAMLTree.new
builder << { :foo => 'bar' }
builder.tree # => #<Psych::Nodes::Stream .. }

Direct Known Subclasses

Stream, JSONTree

Defined Under Namespace

Classes: Registrar

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(emitter, ss, options) ⇒ YAMLTree

Returns a new instance of YAMLTree.



65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
# File 'lib/psych/visitors/yaml_tree.rb', line 65

def initialize emitter, ss, options
  super()
  @started    = false
  @finished   = false
  @emitter    = emitter
  @st         = Registrar.new
  @ss         = ss
  @options    = options
  @line_width = options[:line_width]
  if @line_width && @line_width < 0
    if @line_width == -1
      # Treat -1 as unlimited line-width, same as libyaml does.
      @line_width = nil
    else
      fail(ArgumentError, "Invalid line_width #{@line_width}, must be non-negative or -1 for unlimited.")
    end
  end
  @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 Attribute Details

#finishedObject (readonly) Also known as: finished?

Returns the value of attribute finished.



45
46
47
# File 'lib/psych/visitors/yaml_tree.rb', line 45

def finished
  @finished
end

#startedObject (readonly) Also known as: started?

Returns the value of attribute started.



45
46
47
# File 'lib/psych/visitors/yaml_tree.rb', line 45

def started
  @started
end

Class Method Details

.create(options = {}, emitter = nil) ⇒ Object



49
50
51
52
53
54
# File 'lib/psych/visitors/yaml_tree.rb', line 49

def self.create options = {}, emitter = nil
  emitter      ||= TreeBuilder.new
  class_loader = ClassLoader.new
  ss           = ScalarScanner.new class_loader
  new(emitter, ss, options)
end

.new(emitter = nil, ss = nil, options = nil) ⇒ Object



56
57
58
59
60
61
62
63
# File 'lib/psych/visitors/yaml_tree.rb', line 56

def self.new emitter = nil, ss = nil, options = nil
  return super if emitter && ss && options

  if $VERBOSE
    warn "This API is deprecated, please pass an emitter, scalar scanner, and options or call #{self}.create() (#{caller.first})"
  end
  create emitter, ss
end

Instance Method Details

#accept(target) ⇒ Object



132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
# File 'lib/psych/visitors/yaml_tree.rb', line 132

def accept target
  # return any aliases we find
  if @st.key? target
    oid         = @st.id_for target
    node        = @st.node_for target
    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

#finishObject



101
102
103
104
105
# File 'lib/psych/visitors/yaml_tree.rb', line 101

def finish
  @emitter.end_stream.tap do
    @finished = true
  end
end

#push(object) ⇒ Object Also known as: <<



112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
# File 'lib/psych/visitors/yaml_tree.rb', line 112

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 !@emitter.streaming?
end

#start(encoding = Nodes::Stream::UTF8) ⇒ Object



95
96
97
98
99
# File 'lib/psych/visitors/yaml_tree.rb', line 95

def start encoding = Nodes::Stream::UTF8
  @emitter.start_stream(encoding).tap do
    @started = true
  end
end

#treeObject



107
108
109
110
# File 'lib/psych/visitors/yaml_tree.rb', line 107

def tree
  finish unless finished?
  @emitter.root
end

#visit_Array(o) ⇒ Object



404
405
406
407
408
409
410
411
412
# File 'lib/psych/visitors/yaml_tree.rb', line 404

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_BasicObject(o) ⇒ Object



426
427
428
429
430
431
432
433
434
435
436
# File 'lib/psych/visitors/yaml_tree.rb', line 426

def visit_BasicObject o
  tag = Psych.dump_tags[o.class]
  tag ||= "!ruby/marshalable:#{o.class.name}"

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

  o.marshal_dump.each(&method(:accept))

  @emitter.end_mapping
end

#visit_BigDecimal(o) ⇒ Object



306
307
308
# File 'lib/psych/visitors/yaml_tree.rb', line 306

def visit_BigDecimal o
  @emitter.scalar o._dump, nil, '!ruby/object:BigDecimal', false, false, Nodes::Scalar::ANY
end

#visit_Class(o) ⇒ Object

Raises:

  • (TypeError)


367
368
369
370
# File 'lib/psych/visitors/yaml_tree.rb', line 367

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) ⇒ Object



278
279
280
281
282
283
284
285
286
# File 'lib/psych/visitors/yaml_tree.rb', line 278

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_DateTime(o) ⇒ Object



250
251
252
253
254
255
256
257
258
# File 'lib/psych/visitors/yaml_tree.rb', line 250

def visit_DateTime o
  formatted = if o.offset.zero?
                o.strftime("%Y-%m-%d %H:%M:%S.%9N Z".freeze)
              else
                o.strftime("%Y-%m-%d %H:%M:%S.%9N %:z".freeze)
              end
  tag = '!ruby/object:DateTime'
  register o, @emitter.scalar(formatted, nil, tag, false, false, Nodes::Scalar::ANY)
end

#visit_Encoding(o) ⇒ Object



175
176
177
178
# File 'lib/psych/visitors/yaml_tree.rb', line 175

def visit_Encoding o
  tag = "!ruby/encoding"
  @emitter.scalar o.name, nil, tag, false, false, Nodes::Scalar::ANY
end

#visit_Exception(o) ⇒ Object



208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
# File 'lib/psych/visitors/yaml_tree.rb', line 208

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_Float(o) ⇒ Object



295
296
297
298
299
300
301
302
303
304
# File 'lib/psych/visitors/yaml_tree.rb', line 295

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) ⇒ Object



380
381
382
383
384
385
386
387
388
389
390
391
# File 'lib/psych/visitors/yaml_tree.rb', line 380

def visit_Hash o
  if o.class == ::Hash
    register(o, @emitter.start_mapping(nil, nil, true, Psych::Nodes::Mapping::BLOCK))
    o.each do |k,v|
      accept k
      accept v
    end
    @emitter.end_mapping
  else
    visit_hash_subclass o
  end
end

#visit_Integer(o) ⇒ Object Also known as: visit_TrueClass, visit_FalseClass, visit_Date



288
289
290
# File 'lib/psych/visitors/yaml_tree.rb', line 288

def visit_Integer o
  @emitter.scalar o.to_s, nil, nil, true, false, Nodes::Scalar::ANY
end

#visit_Module(o) ⇒ Object

Raises:

  • (TypeError)


362
363
364
365
# File 'lib/psych/visitors/yaml_tree.rb', line 362

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_NameError(o) ⇒ Object



227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
# File 'lib/psych/visitors/yaml_tree.rb', line 227

def visit_NameError o
  tag = ['!ruby/exception', o.class.name].join ':'

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

  {
    'message'   => o.message.to_s,
    '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_NilClass(o) ⇒ Object



414
415
416
# File 'lib/psych/visitors/yaml_tree.rb', line 414

def visit_NilClass o
  @emitter.scalar('', nil, 'tag:yaml.org,2002:null', true, false, Nodes::Scalar::ANY)
end

#visit_Object(o) ⇒ Object



180
181
182
183
184
185
186
187
188
189
190
191
192
# File 'lib/psych/visitors/yaml_tree.rb', line 180

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) ⇒ Object



167
168
169
170
171
172
173
# File 'lib/psych/visitors/yaml_tree.rb', line 167

def visit_Psych_Omap o
  seq = @emitter.start_sequence(nil, 'tag:yaml.org,2002:omap', false, Nodes::Sequence::BLOCK)
  register(o, seq)

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

#visit_Psych_Set(o) ⇒ Object



393
394
395
396
397
398
399
400
401
402
# File 'lib/psych/visitors/yaml_tree.rb', line 393

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) ⇒ Object



372
373
374
375
376
377
378
# File 'lib/psych/visitors/yaml_tree.rb', line 372

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) ⇒ Object



265
266
267
268
269
270
271
272
273
274
275
276
# File 'lib/psych/visitors/yaml_tree.rb', line 265

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) ⇒ Object



246
247
248
# File 'lib/psych/visitors/yaml_tree.rb', line 246

def visit_Regexp o
  register o, @emitter.scalar(o.inspect, nil, '!ruby/regexp', false, false, Nodes::Scalar::ANY)
end

#visit_String(o) ⇒ Object



310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
# File 'lib/psych/visitors/yaml_tree.rb', line 310

def visit_String o
  plain = true
  quote = true
  style = Nodes::Scalar::PLAIN
  tag   = nil

  if binary?(o)
    o     = [o].pack('m0')
    tag   = '!binary' # FIXME: change to below when syck is removed
    #tag   = 'tag:yaml.org,2002:binary'
    style = Nodes::Scalar::LITERAL
    plain = false
    quote = false
  elsif o =~ /\n(?!\Z)/  # match \n except blank line at the end of string
    style = Nodes::Scalar::LITERAL
  elsif o == '<<'
    style = Nodes::Scalar::SINGLE_QUOTED
    tag   = 'tag:yaml.org,2002:str'
    plain = false
    quote = false
  elsif @line_width && o.length > @line_width
    style = Nodes::Scalar::FOLDED
  elsif o =~ /^[^[:word:]][^"]*$/
    style = Nodes::Scalar::DOUBLE_QUOTED
  elsif not String === @ss.tokenize(o) or /\A0[0-7]*[89]/ =~ o
    style = Nodes::Scalar::SINGLE_QUOTED
  end

  is_primitive = o.class == ::String
  ivars = find_ivars o, is_primitive

  if ivars.empty?
    unless is_primitive
      tag = "!ruby/string:#{o.class}"
      plain = false
      quote = false
    end
    @emitter.scalar o, 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 o, nil, tag, plain, quote, style

    dump_ivars o

    @emitter.end_mapping
  end
end

#visit_Struct(o) ⇒ Object



194
195
196
197
198
199
200
201
202
203
204
205
206
# File 'lib/psych/visitors/yaml_tree.rb', line 194

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) ⇒ Object



418
419
420
421
422
423
424
# File 'lib/psych/visitors/yaml_tree.rb', line 418

def visit_Symbol o
  if o.empty?
    @emitter.scalar "", nil, '!ruby/symbol', false, false, Nodes::Scalar::ANY
  else
    @emitter.scalar ":#{o}", nil, nil, true, false, Nodes::Scalar::ANY
  end
end

#visit_Time(o) ⇒ Object



260
261
262
263
# File 'lib/psych/visitors/yaml_tree.rb', line 260

def visit_Time o
  formatted = format_time o
  register o, @emitter.scalar(formatted, nil, nil, true, false, Nodes::Scalar::ANY)
end