Class: TSV::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/rbbt/tsv/parser.rb

Defined Under Namespace

Classes: END_PARSING, SKIP_LINE

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stream = nil, options = {}) ⇒ Parser

Returns a new instance of Parser.



385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
 
# File 'lib/rbbt/tsv/parser.rb', line 385

def initialize(stream = nil, options = {})
  @header_hash = Misc.process_options(options, :header_hash) || "#"
  @sep = Misc.process_options(options, :sep) || "\t"
  @tsv_grep = Misc.process_options(options, :tsv_grep) 
  stream = TSV.get_stream stream
  @stream = stream


  header_options = parse_header(stream)

  options = header_options.merge options

  @type ||= Misc.process_options(options, :type) || :double
  @type ||= :double

  @identifiers = Misc.process_options(options, :identifiers) 

  @filename = Misc.process_options(options, :filename) 
  @filename ||= stream.filename if stream.respond_to? :filename

  @sep2 = Misc.process_options(options, :sep2) || "|"
  @cast = Misc.process_options options, :cast; @cast = @cast.to_sym if String === @cast
  @type ||= Misc.process_options options, :type
  @fix = Misc.process_options(options, :fix) 
  @select= Misc.process_options options, :select
  @zipped = Misc.process_options options, :zipped
  @namespace = Misc.process_options options, :namespace
  merge = Misc.process_options(options, :merge)
  merge = @zipped if merge.nil?
  merge = false if merge.nil?

  fields = options[:fields]
  fix_fields(options)

  @type = @type.strip.to_sym if String === @type
  #@type ||= :double if merge == true

  case @type
  when :double 
    self.instance_eval do alias get_values get_values_double end
    self.instance_eval do alias cast_values cast_values_double end
    case
    when (merge and not zipped)
        self.instance_eval do alias add_to_data add_to_data_merge end
    when (merge and zipped)
        self.instance_eval do alias add_to_data add_to_data_merge_zipped end
    when zipped
        self.instance_eval do alias add_to_data add_to_data_zipped end
    else
      self.instance_eval do alias add_to_data add_to_data_no_merge_double end
    end
  when :single
    if header_options[:type] == :flat
      self.instance_eval do alias get_values get_values_single_from_flat end
      self.instance_eval do alias cast_values cast_values_single end
      self.instance_eval do alias add_to_data add_to_data_no_merge_double end
    else
      self.instance_eval do alias get_values get_values_single end
      self.instance_eval do alias cast_values cast_values_single end
      self.instance_eval do alias add_to_data add_to_data_no_merge_list end
    end
  when :list
    self.instance_eval do alias get_values get_values_list end
    self.instance_eval do alias cast_values cast_values_list end
    self.instance_eval do alias add_to_data add_to_data_no_merge_list end
  when :flat
    @take_all = true if field_positions.nil?
    self.instance_eval do alias cast_values cast_values_flat end
    merge = true if key_position and key_position != 0 and field_positions.nil?
    if merge 
      self.instance_eval do alias get_values get_values_flat_merge end
      if key_position and key_position != 0 and field_positions.nil?
        self.instance_eval do alias add_to_data add_to_data_flat_merge_keys end
      else
        self.instance_eval do alias add_to_data add_to_data_flat_merge_double end
      end
    else
      self.instance_eval do alias get_values get_values_flat end
      if key_position and key_position != 0 and field_positions.nil?
        self.instance_eval do alias add_to_data add_to_data_flat_keys end
      else
        self.instance_eval do alias add_to_data add_to_data_flat end
      end
    end
  else
    raise "Unknown TSV type: #{@type.inspect}"
  end


  @straight = false if @sep != "\t" or not @cast.nil? or merge or (@type == :flat and fields)
end

Instance Attribute Details

#cast ⇒ Object

Returns the value of attribute cast.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def cast
  @cast
end

#field_positions ⇒ Object

Returns the value of attribute field_positions.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def field_positions
  @field_positions
end

#fields ⇒ Object

Returns the value of attribute fields.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def fields
  @fields
end

#filename ⇒ Object

Returns the value of attribute filename.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def filename
  @filename
end

#first_line ⇒ Object

Returns the value of attribute first_line.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def first_line
  @first_line
end

#fix ⇒ Object

Returns the value of attribute fix.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def fix
  @fix
end

#header_hash ⇒ Object

Returns the value of attribute header_hash.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def header_hash
  @header_hash
end

#identifiers ⇒ Object

Returns the value of attribute identifiers.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def identifiers
  @identifiers
end

#key_field ⇒ Object

Returns the value of attribute key_field.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def key_field
  @key_field
end

#key_position ⇒ Object

Returns the value of attribute key_position.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def key_position
  @key_position
end

#namespace ⇒ Object

Returns the value of attribute namespace.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def namespace
  @namespace
end

#preamble ⇒ Object

Returns the value of attribute preamble.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def preamble
  @preamble
end

#select ⇒ Object

Returns the value of attribute select.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def select
  @select
end

#sep ⇒ Object

Returns the value of attribute sep.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def sep
  @sep
end

#sep2 ⇒ Object

Returns the value of attribute sep2.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def sep2
  @sep2
end

#serializer ⇒ Object

Returns the value of attribute serializer.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def serializer
  @serializer
end

#straight ⇒ Object

Returns the value of attribute straight.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def straight
  @straight
end

#stream ⇒ Object

Returns the value of attribute stream.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def stream
  @stream
end

#take_all ⇒ Object

Returns the value of attribute take_all.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def take_all
  @take_all
end

#type ⇒ Object

Returns the value of attribute type.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def type
  @type
end

#zipped ⇒ Object

Returns the value of attribute zipped.



4
5
6
 
# File 'lib/rbbt/tsv/parser.rb', line 4

def zipped
  @zipped
end

Class Method Details

.traverse(stream, options = {}, &block) ⇒ Object 



616
617
618
619
 
# File 'lib/rbbt/tsv/parser.rb', line 616

def self.traverse(stream, options = {}, &block)
  parser = Parser.new(stream, options)
  parser.traverse(options, &block)
end

Instance Method Details

#add_to_data_flat(data, key, values) ⇒ Object 



183
184
185
186
 
# File 'lib/rbbt/tsv/parser.rb', line 183

def add_to_data_flat(data, key, values)
  data[key] = values unless data.include? key
  nil
end

#add_to_data_flat_keys(data, key, values) ⇒ Object 



178
179
180
181
 
# File 'lib/rbbt/tsv/parser.rb', line 178

def add_to_data_flat_keys(data, key, values)
  data[key] = values unless data.include? key
  nil
end

#add_to_data_flat_merge(data, key, values) ⇒ Object 



188
189
190
191
192
193
194
195
 
# File 'lib/rbbt/tsv/parser.rb', line 188

def add_to_data_flat_merge(data, key, values)
  if data.include? key
    data[key] = data[key].concat values
  else
    data[key] = values
  end
  nil
end

#add_to_data_flat_merge_double(data, keys, values) ⇒ Object 



197
198
199
200
201
202
203
204
205
206
 
# File 'lib/rbbt/tsv/parser.rb', line 197

def add_to_data_flat_merge_double(data, keys, values)
  keys.each do |key|
    if data.include? key
      data[key] = data[key].concat values
    else
      data[key] = values
    end
  end
  nil
end

#add_to_data_flat_merge_keys(data, keys, values) ⇒ Object 



208
209
210
211
212
213
214
215
216
217
 
# File 'lib/rbbt/tsv/parser.rb', line 208

def add_to_data_flat_merge_keys(data, keys, values)
  keys.each do |key|
    if data.include? key
      data[key] = data[key].concat values
    else
      data[key] = values.dup
    end
  end
  nil
end

#add_to_data_merge(data, keys, values) ⇒ Object 



227
228
229
230
231
232
233
234
235
236
237
238
239
240
 
# File 'lib/rbbt/tsv/parser.rb', line 227

def add_to_data_merge(data, keys, values)
  keys.uniq.each do |key|
    if data.include? key
      new = data[key]
      new.each_with_index do |old, i|
        old.concat values[i]
      end
      data[key] = new
    else
      data[key] = values
    end
  end
  nil
end

#add_to_data_merge_zipped(data, keys, values) ⇒ Object 



242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
 
# File 'lib/rbbt/tsv/parser.rb', line 242

def add_to_data_merge_zipped(data, keys, values)
  num = keys.length

  if values.first.length > 1 and num == 1
    keys = keys * values.first.length
    num = keys.length
  end

  values = values.collect{|v| v.length != num ? [v.first] * num : v}
  all = values.unshift keys
  Misc.zip_fields(all).each do |values|
    key = values.shift
    if data.include? key
      data[key] = data[key].zip(values).collect do |old, new|
        old.push new
        old
      end
    else
      data[key] = values.collect{|v| [v]}
    end
  end
  nil
end

#add_to_data_no_merge_double(data, keys, values) ⇒ Object 



219
220
221
222
223
224
225
 
# File 'lib/rbbt/tsv/parser.rb', line 219

def add_to_data_no_merge_double(data, keys, values)
  keys.each do |key|
    next if data.include? key
    data[key] = values 
  end
  nil
end

#add_to_data_no_merge_list(data, key, values) ⇒ Object 



173
174
175
176
 
# File 'lib/rbbt/tsv/parser.rb', line 173

def add_to_data_no_merge_list(data, key, values)
  data[key] = values unless data.include? key
  nil
end

#add_to_data_zipped(data, keys, values) ⇒ Object 



266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
 
# File 'lib/rbbt/tsv/parser.rb', line 266

def add_to_data_zipped(data, keys, values)
  num = keys.length

  if values.first.length > 1 and num == 1
    keys = keys * values.first.length
    num = keys.length
  end

  values = values.collect{|v| v.length != num ? [v.first] * num : v}
  all = values.unshift keys
  Misc.zip_fields(all).each do |values|
    key = values.shift
    next if data.include? key
    data[key] = values.collect{|v| [v]}
  end
  nil
end

#all_fields ⇒ Object 



9
10
11
12
 
# File 'lib/rbbt/tsv/parser.rb', line 9

def all_fields
  all = [key_field] + fields
  NamedArray.setup all, all
end

#annotate(data) ⇒ Object 



489
490
491
 
# File 'lib/rbbt/tsv/parser.rb', line 489

def annotate(data)
  setup(data)
end

#cast? ⇒ Boolean

Returns:

  • (Boolean) 


69
70
71
 
# File 'lib/rbbt/tsv/parser.rb', line 69

def cast?
  !! @cast
end

#cast_values_double(values) ⇒ Object 



314
315
316
317
318
319
320
321
 
# File 'lib/rbbt/tsv/parser.rb', line 314

def cast_values_double(values)
  case
  when Symbol === cast
    values.collect{|list| list.collect{|v| v.nil? or v.empty? ? nil : v.send(cast)}}
  when Proc === cast
    values.collect{|list| list.collect{|v| v.nil? or v.empty? ? nil : cast.call(v) }}
  end
end

#cast_values_flat(values) ⇒ Object 



305
306
307
308
309
310
311
312
 
# File 'lib/rbbt/tsv/parser.rb', line 305

def cast_values_flat(values)
  case
  when Symbol === cast
    values.collect{|v| v.nil? or v.empty? ? nil : v.send(cast)}
  when Proc === cast
    values.collect{|v| v.nil? or v.empty? ? nil : cast.call(v) }
  end
end

#cast_values_list(values) ⇒ Object 



296
297
298
299
300
301
302
303
 
# File 'lib/rbbt/tsv/parser.rb', line 296

def cast_values_list(values)
  case
  when Symbol === cast
    values.collect{|v| v.nil? or v.empty? ? nil : v.send(cast)}
  when Proc === cast
    values.collect{|v| v.nil? or v.empty? ? nil : cast.call(v)}
  end
end

#cast_values_single(value) ⇒ Object 



285
286
287
288
289
290
291
292
293
294
 
# File 'lib/rbbt/tsv/parser.rb', line 285

def cast_values_single(value)
  case
  when (value.nil? or value.empty?)
    nil
  when Symbol === cast
    value.send(cast)
  when Proc === cast
    cast.call value
  end
end

#chop_line(line) ⇒ Object 



73
74
75
 
# File 'lib/rbbt/tsv/parser.rb', line 73

def chop_line(line)
  @sep == " " ? line.split(/ /, -1) : line.split(@sep, -1)
end

#fix_fields(options) ⇒ Object 



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
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
 
# File 'lib/rbbt/tsv/parser.rb', line 327

def fix_fields(options)
  key_field = Misc.process_options options, :key_field
  fields    = Misc.process_options options, :fields


  if (key_field.nil? or key_field == 0 or key_field == :key) and
    (fields.nil? or fields == @fields or (not @fields.nil? and fields == (1..@fields.length).to_a))

    @straight = true
    return
  else
    @straight = false

    case
    when (key_field.nil? or (not Integer === key_field and @key_field.nil?) or key_field == @key_field or key_field == 0)
      @key_position = 0
    when Integer === key_field
      @key_position = key_field
    when String === key_field
      @key_position = @fields.dup.unshift(@key_field).index key_field
      raise "Key field #{ key_field } was not found" if @key_position.nil?
    when :key == key_field
      @key_position = 0
    else
      raise "Format of key_field not understood: #{key_field.inspect}"
    end

    if (fields.nil? or (not (Array === fields and Integer === fields.first) and @fields.nil?) or fields == @fields or (not @fields.nil? and fields == (1..@fields.length).to_a))
      if not @fields.nil? and type != :flat
        @field_positions = (0..@fields.length).to_a
        @field_positions.delete @key_position
      end
    else
      fields = [fields] if not Array === fields
      @field_positions = fields.collect{|field|
        case
        when Integer === field
          field
        when String === field
          pos = @fields.dup.unshift(@key_field).index field
          raise "Field not identified: #{ field }" if pos.nil?
          pos
        else
          raise "Format of fields not understood: #{field.inspect}"
        end
      }
    end

    new_key_field = @fields.dup.unshift(@key_field)[@key_position] if not @fields.nil?
    @fields = @fields.dup.unshift(@key_field).values_at *@field_positions if not @fields.nil? and not @field_positions.nil?
    @fields ||= fields if Array === fields and String === fields.first
    @fields = [@key_field] if new_key_field != @key_field and type == :flat and @field_positions.nil?
    @key_field = new_key_field 
    @key_field ||= key_field if String === key_field

  end
end

#get_values_double(parts) ⇒ Object 



111
112
113
114
115
116
117
118
119
120
121
122
123
 
# File 'lib/rbbt/tsv/parser.rb', line 111

def get_values_double(parts)
  return parts.shift.split(@sep2, -1), parts.collect{|value| value.split(@sep2, -1)} if field_positions.nil? and key_position.nil?
  keys = parts[key_position].split(@sep2, -1)
  values = case
           when field_positions.nil?
            parts.tap{|o| o.delete_at key_position}
           when field_positions.empty?
             []
           else
             parts.values_at *field_positions
           end.collect{|value| value.nil? ? [] : value.split(@sep2, -1) }
  [keys, values]
end

#get_values_flat(parts) ⇒ Object 



167
168
169
170
 
# File 'lib/rbbt/tsv/parser.rb', line 167

def get_values_flat(parts)
  keys, values = get_values_flat_merge(parts)
  [keys.first, values]
end

#get_values_flat_inverse(parts) ⇒ Object 



125
126
127
128
129
 
# File 'lib/rbbt/tsv/parser.rb', line 125

def get_values_flat_inverse(parts)
  value = parts.shift
  keys = parts
  [keys, [value]]
end

#get_values_flat_merge(parts) ⇒ 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/rbbt/tsv/parser.rb', line 132

def get_values_flat_merge(parts)
  begin
    orig = parts

    if key_position and key_position != 0 and field_positions.nil?
      value = parts.shift.split(@sep2, -1)
      keys = parts.collect{|p| p.split(@sep2, -1) }.flatten
      return [keys, value]
    end

    return parts.shift.split(@sep2, -1), parts.collect{|value| value.split(@sep2, -1)}.flatten if 
    field_positions.nil? and (key_position.nil? or key_position == 0)
  rescue
    raise $!
  end

  str = parts[key_position]
  keys = str.split(@sep2, -1)

  if @take_all
    values = parts.collect{|e| e.split(@sep2, -1) }.flatten
  else
    if field_positions.nil?
      parts.delete_at key_position
      values = parts.first
    else
      values = parts[field_positions.first]
    end

    values = values.split(@sep2, -1)
  end

  [keys, values]
end

#get_values_list(parts) ⇒ Object 



95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
 
# File 'lib/rbbt/tsv/parser.rb', line 95

def get_values_list(parts)
  return parts.shift, parts if field_positions.nil? and key_position.nil?
  key = parts[key_position]

  values = case
           when field_positions.nil?
            parts.tap{|o| o.delete_at key_position}
           when field_positions.empty?
             []
           else
            parts.values_at *field_positions
           end

  [key, values]
end

#get_values_single(parts) ⇒ Object 



88
89
90
91
92
93
 
# File 'lib/rbbt/tsv/parser.rb', line 88

def get_values_single(parts)
  return parts.shift, parts.first if field_positions.nil? and key_position.nil?
  key = parts[key_position]
  value = parts[(field_positions.nil? or field_positions.empty?) ? 0 : field_positions.first]
  [key, value]
end

#get_values_single_from_flat(parts) ⇒ Object 



77
78
79
80
81
82
83
84
85
86
 
# File 'lib/rbbt/tsv/parser.rb', line 77

def get_values_single_from_flat(parts)
  return parts.shift, parts.first if field_positions.nil? and key_position.nil?
  if key_position == 0
    [parts.shift, parts.first]
  else
    key = parts.shift
    [parts, key]
  end

end

#identify_field(field) ⇒ Object 



612
613
614
 
# File 'lib/rbbt/tsv/parser.rb', line 612

def identify_field(field)
  TSV.identify_field(key_field, fields, field)
end

#options ⇒ Object 



493
494
495
496
497
498
499
500
501
502
503
 
# File 'lib/rbbt/tsv/parser.rb', line 493

def options
  options = {}
  TSV::ENTRIES.each do |entry|
    if self.respond_to? entry
      value = self.send(entry) 
      options[entry.to_sym] = value unless value.nil?
    end
  end
  options[:sep] = @sep if @sep and @sep != "\t" and @sep != /\t/
  IndiferentHash.setup options
end

#parse_header(stream) ⇒ Object 



14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
 
# File 'lib/rbbt/tsv/parser.rb', line 14

def parse_header(stream)
  options = {}
  @preamble = []

  # Get line

  #Thread.pass while IO.select([stream], nil, nil, 1).nil? if IO === stream
  line = stream.gets
  return {} if line.nil?
  #raise "Empty content: #{ stream.inspect }" if line.nil?
  line = Misc.fixutf8 line.chomp

  # Process options line

  if line and line =~ /^#{@header_hash}: (.*)/
    options = Misc.string2hash $1.chomp
    line = stream.gets
    line = Misc.fixutf8 line.chomp if line
  end

  # Determine separator

  @sep = options[:sep] if options[:sep]

  # Process fields line

  preamble << line if line
  while line and Misc.fixutf8(line) =~ /^#{@header_hash}/ 
    @fields = line.split(@sep)
    @key_field = @fields.shift
    @key_field = @key_field[(0 + header_hash.length)..-1] # Remove initial hash character

    #Thread.pass while IO.select([stream], nil, nil, 1).nil? if IO === stream
    line = (@header_hash != "" ?  stream.gets : nil)
    line = Misc.fixutf8 line.chomp if line
    preamble << line if line
  end

  @preamble = preamble[0..-3] * "\n"

  line ||= stream.gets

  @first_line = line

  options
end

#process(line) ⇒ Object

Raises:



61
62
63
64
65
66
67
 
# File 'lib/rbbt/tsv/parser.rb', line 61

def process(line)
  l = line.chomp
  raise SKIP_LINE if l[0] == "#"[0] or (Proc === @select and not @select.call l)
  l = @fix.call l if Proc === @fix
  raise END_PARSING unless l
  l
end

#rescue_first_line ⇒ Object 



323
324
325
 
# File 'lib/rbbt/tsv/parser.rb', line 323

def rescue_first_line
  @first_line
end

#setup(data) ⇒ Object 



477
478
479
480
481
482
483
484
485
486
487
 
# File 'lib/rbbt/tsv/parser.rb', line 477

def setup(data)
  data.extend TSV unless TSV === data
  data.type = @type
  data.key_field = @key_field
  data.fields = @fields
  data.namespace = @namespace
  data.filename = @filename
  data.identifiers = @identifiers
  data.cast = @cast if Symbol === @cast
  data
end

#traverse(options = {}) ⇒ Object 



505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
 
# File 'lib/rbbt/tsv/parser.rb', line 505

def traverse(options = {})
  monitor, grep, invert_grep, head = Misc.process_options options, :monitor, :grep, :invert_grep, :head
  raise "No block given in TSV::Parser#traverse" unless block_given?

  stream = @stream


  # first line
  line = self.rescue_first_line

  if @tsv_grep

    stream = Open.grep(stream, @tsv_grep, invert_grep)
    stream.no_fail = true
    begin
      match = Open.grep(StringIO.new(line), @tsv_grep, invert_grep).read
      line = stream.gets if match.empty?
    rescue Exception
      Log.exception $!
      line = stream.gets 
    end
  end

  progress_monitor, monitor = monitor, nil if Log::ProgressBar === monitor
  # setup monitor
  if monitor and (stream.respond_to?(:size) or (stream.respond_to?(:stat) and stream.stat.respond_to? :size and stream.respond_to?(:pos)))
    size = case
           when stream.respond_to?(:size)
             stream.size
           else
             stream.stat.size
           end
    size = nil if size.to_i == 0
    desc = "Parsing Stream"
    step = 100
    if Hash === monitor
      desc = monitor[:desc] if monitor.include? :desc 
      step = monitor[:step] if monitor.include? :step 
    end
    progress_monitor = Log::ProgressBar.new_bar(size, :desc => desc)
  elsif progress_monitor 

    size = case
           when stream.respond_to?(:size)
             stream.size
           else
             stream.stat.size
           end

    progress_monitor.max =  size unless size.to_i == 0
  end

  # parser 
  line_num = 1
  begin

    while not line.nil? 
      begin
        if progress_monitor
          progress_monitor.tick(line.bytesize)
        end

        raise SKIP_LINE if line.empty?

        line = Misc.fixutf8(line)
        line = self.process line
        raise SKIP_LINE if line.empty?
        parts = self.chop_line line
        key, values = self.get_values parts
        values = self.cast_values values if self.cast?
        
        yield key, values

        line = stream.gets

        line_num += 1
        raise END_PARSING if head and line_num > head.to_i
      rescue SKIP_LINE
        begin
          line = stream.gets
          next
        rescue IOError
          break
        end
      rescue END_PARSING
        stream.close unless stream.closed?
        begin stream.join; rescue Exception; end if stream.respond_to? :join and not stream.joined?
        break
      rescue Errno::EPIPE
        Log.error "Pipe closed while parsing #{Misc.fingerprint stream}: #{$!.message}"
        stream.abort if stream.respond_to? :abort
        raise $!
      rescue Exception
        Log.error "Exception parsing #{Misc.fingerprint stream}: #{$!.message}"
        stream.abort $! if stream.respond_to? :abort
        raise $!
      end
    end
  ensure
    Log::ProgressBar.remove_bar(progress_monitor)
    stream.close unless stream.closed?
    stream.join if stream.respond_to? :join and not stream.joined?
  end

  self
end