Class: Card::Content::Diff::LCS::Processor

Inherits:
Object
  • Object
show all
Defined in:
lib/card/content/diff/processor.rb

Overview

Compares two lists of chunks and generates a diff

Instance Method Summary collapse

Constructor Details

#initialize(old_words, new_words, old_excludees, new_excludees) ⇒ Processor

Returns a new instance of Processor.



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# File 'lib/card/content/diff/processor.rb', line 7

def initialize old_words, new_words, old_excludees, new_excludees
  @adds = []
  @dels = []
  @words = { old: old_words, new: new_words }
  @excludees =
    ExcludeeIterator.old_and_new old_excludees, new_excludees
end

Instance Method Details

#add_new_excludees ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 90

def add_new_excludees
  @excludees[:new].scan_and_record(@adds) do |element|
    write_adds
    @result.complete << element
  end
end

#del_old_excludees ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 83

def del_old_excludees
  @excludees[:old].scan_and_record(@dels) do |element|
    write_dels
    @result.write_excluded_chunk element
  end
end

#handle_action(action) ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 41

def handle_action action
  case action
  when "-" then del_old_excludees
  when "+" then add_new_excludees
  when "!" then
    del_old_excludees
    add_new_excludees
  else
    write_excludees
  end
end

#interpret_action(prev_action, word) ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 31

def interpret_action prev_action, word
  if (prev_action == word.action) ||
     (prev_action == "-" && word.action == "!") ||
     (prev_action == "!" && word.action == "+")
    handle_action word.action
  else
    write_all
  end
end

#minus(old_element) ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 115

def minus old_element
  @dels << old_element
  @excludees[:old].word_step
end

#plus(new_element) ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 110

def plus new_element
  @adds << new_element
  @excludees[:new].word_step
end

#process_element(old_element, new_element, action) ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 97

def process_element old_element, new_element, action
  case action
  when "-" then minus old_element
  when "+" then plus new_element
  when "!"
    minus old_element
    plus new_element
  else
    write_unchanged new_element
    @excludees[:new].word_step
  end
end

#run(result) ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 15

def run result
  @result = result
  prev_action = nil
  ::Diff::LCS.traverse_balanced(@words[:old], @words[:new]) do |word|
    if prev_action
      interpret_action prev_action, word
    else
      write_excludees
    end
    process_element word.old_element, word.new_element, word.action
    prev_action = word.action
  end
  write_all
  @result
end

#write_adds ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 70

def write_adds
  return if @adds.empty?

  @result.write_added_chunk @adds.join
  @adds = []
end

#write_all ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 53

def write_all
  write_dels
  write_adds
  write_excludees
end

#write_dels ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 63

def write_dels
  return if @dels.empty?

  @result.write_deleted_chunk @dels.join
  @dels = []
end

#write_excludees ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 77

def write_excludees
  while (ex = @excludees[:new].next)
    @result.write_excluded_chunk ex[:element]
  end
end

#write_unchanged(text) ⇒ Object 



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# File 'lib/card/content/diff/processor.rb', line 59

def write_unchanged text
  @result.write_unchanged_chunk text
end