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.



64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
 
# File 'lib/psych/visitors/yaml_tree.rb', line 64

def initialize emitter, ss, options
  super()
  @started    = false
  @finished   = false
  @emitter    = emitter
  @st         = Registrar.new
  @ss         = ss
  @options    = options
  @line_width = options[:line_width]
  @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

#finished ⇒ Object (readonly) Also known as: finished?

Returns the value of attribute finished.



44
45
46
 
# File 'lib/psych/visitors/yaml_tree.rb', line 44

def finished
  @finished
end

#started ⇒ Object (readonly) Also known as: started?

Returns the value of attribute started.



44
45
46
 
# File 'lib/psych/visitors/yaml_tree.rb', line 44

def started
  @started
end

Class Method Details

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



48
49
50
51
52
53
 
# File 'lib/psych/visitors/yaml_tree.rb', line 48

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 



55
56
57
58
59
60
61
62
 
# File 'lib/psych/visitors/yaml_tree.rb', line 55

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 



123
124
125
126
127
128
129
130
131
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
 
# File 'lib/psych/visitors/yaml_tree.rb', line 123

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

#finish ⇒ Object 



92
93
94
95
96
 
# File 'lib/psych/visitors/yaml_tree.rb', line 92

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

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



103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
 
# File 'lib/psych/visitors/yaml_tree.rb', line 103

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 



86
87
88
89
90
 
# File 'lib/psych/visitors/yaml_tree.rb', line 86

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

#tree ⇒ Object 



98
99
100
101
 
# File 'lib/psych/visitors/yaml_tree.rb', line 98

def tree
  finish unless finished?
  @emitter.root
end

#visit_Array(o) ⇒ Object 



395
396
397
398
399
400
401
402
403
 
# File 'lib/psych/visitors/yaml_tree.rb', line 395

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 



417
418
419
420
421
422
423
424
425
426
427
 
# File 'lib/psych/visitors/yaml_tree.rb', line 417

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 



297
298
299
 
# File 'lib/psych/visitors/yaml_tree.rb', line 297

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

#visit_Class(o) ⇒ Object

Raises:

  • (TypeError) 


358
359
360
361
 
# File 'lib/psych/visitors/yaml_tree.rb', line 358

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 



269
270
271
272
273
274
275
276
277
 
# File 'lib/psych/visitors/yaml_tree.rb', line 269

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 



241
242
243
244
245
246
247
248
249
 
# File 'lib/psych/visitors/yaml_tree.rb', line 241

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 



166
167
168
169
 
# File 'lib/psych/visitors/yaml_tree.rb', line 166

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

#visit_Exception(o) ⇒ Object 



199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
 
# File 'lib/psych/visitors/yaml_tree.rb', line 199

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 



286
287
288
289
290
291
292
293
294
295
 
# File 'lib/psych/visitors/yaml_tree.rb', line 286

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 



371
372
373
374
375
376
377
378
379
380
381
382
 
# File 'lib/psych/visitors/yaml_tree.rb', line 371

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 



279
280
281
 
# File 'lib/psych/visitors/yaml_tree.rb', line 279

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

#visit_Module(o) ⇒ Object

Raises:

  • (TypeError) 


353
354
355
356
 
# File 'lib/psych/visitors/yaml_tree.rb', line 353

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 



218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
 
# File 'lib/psych/visitors/yaml_tree.rb', line 218

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 



405
406
407
 
# File 'lib/psych/visitors/yaml_tree.rb', line 405

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

#visit_Object(o) ⇒ Object 



171
172
173
174
175
176
177
178
179
180
181
182
183
 
# File 'lib/psych/visitors/yaml_tree.rb', line 171

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 



158
159
160
161
162
163
164
 
# File 'lib/psych/visitors/yaml_tree.rb', line 158

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) ⇒ Object 



384
385
386
387
388
389
390
391
392
393
 
# File 'lib/psych/visitors/yaml_tree.rb', line 384

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 



363
364
365
366
367
368
369
 
# File 'lib/psych/visitors/yaml_tree.rb', line 363

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 



256
257
258
259
260
261
262
263
264
265
266
267
 
# File 'lib/psych/visitors/yaml_tree.rb', line 256

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 



237
238
239
 
# File 'lib/psych/visitors/yaml_tree.rb', line 237

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

#visit_String(o) ⇒ Object 



301
302
303
304
305
306
307
308
309
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
 
# File 'lib/psych/visitors/yaml_tree.rb', line 301

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

  if binary?(o)
    o     = [o].pack('m').chomp
    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)
    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 



185
186
187
188
189
190
191
192
193
194
195
196
197
 
# File 'lib/psych/visitors/yaml_tree.rb', line 185

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 



409
410
411
412
413
414
415
 
# File 'lib/psych/visitors/yaml_tree.rb', line 409

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 



251
252
253
254
 
# File 'lib/psych/visitors/yaml_tree.rb', line 251

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