Class: TextAlignment::TextAlignment

Inherits:
Object
  • Object
show all
Defined in:
lib/text_alignment/text_alignment.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(str1, str2, mappings = nil) ⇒ TextAlignment

Returns a new instance of TextAlignment.

Raises:

  • (ArgumentError) 


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# File 'lib/text_alignment/text_alignment.rb', line 17

def initialize(str1, str2, mappings = nil)
  raise ArgumentError, "nil string" if str1.nil? || str2.nil?

  mappings ||= TextAlignment::MAPPINGS

  # try exact match
  block_begin = str2.index(str1)
  unless block_begin.nil?
    @block_alignments = [{source:{begin:0, end:str1.length}, target:{begin:block_begin, end:block_begin + str1.length}, delta:block_begin}]
    return @block_alignments
  end

  anchor_finder = TextAlignment::AnchorFinder.new(str1, str2)

  # To collect matched blocks
  mblocks = []
  while anchor = anchor_finder.get_next_anchor
    last = mblocks.last
    if last && (anchor[:source][:begin] == last[:source][:end] + 1) && (anchor[:target][:begin] == last[:target][:end] + 1)
      last[:source][:end] = anchor[:source][:end]
      last[:target][:end] = anchor[:target][:end]
    else
      mblocks << anchor
    end
  end

  pp mblocks
  puts "-----"
  puts

  # mblocks.each do |b|
  #  p [b[:source], b[:target]]
  #  puts "---"
  #  puts str1[b[:source][:begin] ... b[:source][:end]]
  #  puts "---"
  #  puts str2[b[:target][:begin] ... b[:target][:end]]
  #  puts "====="
  #  puts
  # end
  # puts "-=-=-=-=-"
  # puts

  ## To find block alignments
  @block_alignments = []
  return if mblocks.empty?

  # Initial step
  if mblocks[0][:source][:begin] > 0
    e1 = mblocks[0][:source][:begin]
    e2 = mblocks[0][:target][:begin]

    if mblocks[0][:target][:begin] == 0
      @block_alignments << {source:{begin:0, end:e1}, target:{begin:0, end:0}, alignment: :empty}
    else
      _str1 = str1[0 ... e1]
      _str2 = str2[0 ... e2]

      unless _str1.strip.empty?
        if _str2.strip.empty?
          @block_alignments << {source:{begin:0, end:e1}, target:{begin:0, end:e2}, alignment: :empty}
        else
          len_min = [_str1.length, _str2.length].min
          len_buffer = (len_min * (1 + TextAlignment::BUFFER_RATE)).to_i + TextAlignment::BUFFER_MIN
          b1 = _str1.length < len_buffer ? 0 : e1 - len_buffer
          b2 = _str2.length < len_buffer ? 0 : e2 - len_buffer

          @block_alignments << {source:{begin:0, end:b1}, target:{begin:0, end:b2}, alignment: :empty} if b1 > 0

          alignment = TextAlignment::MixedAlignment.new(_str1.downcase, _str2.downcase, mappings)
          if alignment.similarity < 0.6
            @block_alignments << {source:{begin:b1, end:e1}, target:{begin:0, end:e2}, alignment: :empty}
          else
            @block_alignments << {source:{begin:b1, end:e1}, target:{begin:0, end:e2}, alignment:alignment}
          end
        end
      end
    end
  end
  @block_alignments << mblocks[0]

  (1 ... mblocks.length).each do |i|
    b1 = mblocks[i - 1][:source][:end]
    b2 = mblocks[i - 1][:target][:end]
    e1 = mblocks[i][:source][:begin]
    e2 = mblocks[i][:target][:begin]
    _str1 = str1[b1 ... e1]
    _str2 = str2[b2 ... e2]
    unless _str1.strip.empty?
      if _str2.strip.empty?
        @block_alignments << {source:{begin:b1, end:e1}, target:{begin:b2, end:e2}, alignment: :empty}
      else
        alignment = TextAlignment::MixedAlignment.new(_str1.downcase, _str2.downcase, mappings)
        if alignment.similarity < 0.6
          @block_alignments << {source:{begin:b1, end:e1}, target:{begin:b2, end:e2}, alignment: :empty}
        else
          @block_alignments << {source:{begin:b1, end:e1}, target:{begin:b2, end:e2}, alignment:alignment}
        end
      end
    end
    @block_alignments << mblocks[i]
  end

  # Final step
  if mblocks[-1][:source][:end] < str1.length
    b1 = mblocks[-1][:source][:end]
    b2 = mblocks[-1][:target][:end]

    if mblocks[-1][:target][:end] < str2.length

    else
      e1 = str1.length
      e2 = str2.length
      @block_alignments << {source:{begin:b1, end:e1}, target:{begin:b2, end:e2}, alignment: :empty}
    end
  end

  if  mblocks[-1][:source][:end] < str1.length && mblocks[-1][:target][:end] < str2.length
    b1 = mblocks[-1][:source][:end]
    b2 = mblocks[-1][:target][:end]
    _str1 = str1[b1 ... -1]
    _str2 = str2[b2 ... -1]

    unless _str1.strip.empty?
      if _str2.strip.empty?
        @block_alignments << {source:{begin:b1, end:str1.length}, target:{begin:b2, end:str2.length}, alignment: :empty}
      else
        len_min = [_str1.length, _str2.length].min
        len_buffer = (len_min * (1 + TextAlignment::BUFFER_RATE)).to_i + TextAlignment::BUFFER_MIN
        e1 = _str1.length < len_buffer ? str1.length : b1 + len_buffer
        e2 = _str2.length < len_buffer ? str2.length : b2 + len_buffer
        _str1 = str1[b1 ... e1]
        _str2 = str2[b2 ... e2]

        alignment = TextAlignment::MixedAlignment.new(_str1.downcase, _str2.downcase, mappings)
        if alignment.similarity < 0.6
          @block_alignments << {source:{begin:b1, end:e1}, target:{begin:b2, end:e2}, alignment: :empty}
        else
          @block_alignments << {source:{begin:b1, end:e1}, target:{begin:b2, end:e2}, alignment:alignment}
        end

        @block_alignments << {source:{begin:e1, end:-1}, target:{begin:e2, end:-1}, alignment: :empty} if e1 < str1.length
      end
    end
  end

  @block_alignments.each do |a|
    a[:delta] = a[:target][:begin] - a[:source][:begin]
  end
end

Instance Attribute Details

#block_alignments ⇒ Object (readonly)

Returns the value of attribute block_alignments.



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# File 'lib/text_alignment/text_alignment.rb', line 13

def block_alignments
  @block_alignments
end

#lost_annotations ⇒ Object (readonly)

Returns the value of attribute lost_annotations.



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# File 'lib/text_alignment/text_alignment.rb', line 15

def lost_annotations
  @lost_annotations
end

#similarity ⇒ Object (readonly)

Returns the value of attribute similarity.



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# File 'lib/text_alignment/text_alignment.rb', line 14

def similarity
  @similarity
end

Instance Method Details

#transform_a_span(span) ⇒ Object 



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# File 'lib/text_alignment/text_alignment.rb', line 205

def transform_a_span(span)
  {begin: transform_begin_position(span[:begin]), end: transform_end_position(span[:end])}
end

#transform_begin_position(begin_position) ⇒ Object 



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# File 'lib/text_alignment/text_alignment.rb', line 167

def transform_begin_position(begin_position)
  i = @block_alignments.index{|b| b[:source][:end] > begin_position}
  block_alignment = @block_alignments[i]

  b = if block_alignment[:alignment].nil?
    begin_position + block_alignment[:delta]
  elsif block_alignment[:alignment] == :empty
    if begin_position == block_alignment[:source][:begin]
      block_alignment[:target][:begin]
    else
      # raise "lost annotation"
      nil
    end
  else
    r = block_alignment[:alignment].transform_begin_position(begin_position - block_alignment[:source][:begin])
    r.nil? ? nil : r + block_alignment[:target][:begin]
  end
end

#transform_denotations!(denotations) ⇒ Object 



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# File 'lib/text_alignment/text_alignment.rb', line 213

def transform_denotations!(denotations)
  return nil if denotations.nil?
  @lost_annotations = []

  denotations.each do |d|
    begin
      d.begin = transform_begin_position(d.begin);
      d.end = transform_end_position(d.end);
    rescue
      @lost_annotations << d
      d.begin = nil
      d.end = nil
    end
  end

  @lost_annotations
end

#transform_end_position(end_position) ⇒ Object 



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# File 'lib/text_alignment/text_alignment.rb', line 186

def transform_end_position(end_position)
  i = @block_alignments.index{|b| b[:source][:end] >= end_position}
  block_alignment = @block_alignments[i]

  e = if block_alignment[:alignment].nil?
    end_position + block_alignment[:delta]
  elsif block_alignment[:alignment] == :empty
    if end_position == block_alignment[:source][:end]
      block_alignment[:target][:end]
    else
      # raise "lost annotation"
      nil
    end
  else
    r = block_alignment[:alignment].transform_end_position(end_position - block_alignment[:source][:begin])
    r.nil? ? nil : r + block_alignment[:target][:begin]
  end
end

#transform_hdenotations(hdenotations) ⇒ Object 



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# File 'lib/text_alignment/text_alignment.rb', line 231

def transform_hdenotations(hdenotations)
  return nil if hdenotations.nil?
  @lost_annotations = []

  r = hdenotations.collect do |d|
    new_d = begin
      d.dup.merge({span:transform_a_span(d[:span])})
    rescue
      @lost_annotations << d
      nil
    end
  end.compact

  r
end

#transform_spans(spans) ⇒ Object 



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# File 'lib/text_alignment/text_alignment.rb', line 209

def transform_spans(spans)
  spans.map{|span| transform_a_span(span)}
end