Class: Diff::Display::Unified::Generator

Inherits:
Object
  • Object
show all
Defined in:
lib/diff/display/unified/generator.rb

Overview

Processes the diff and generates a Data object which contains the resulting data structure.

The run class method is fed a diff and returns a Data object. It will accept as its argument a String, an Array or a File object (or anything that responds to #each):

Diff::Display::Unified::Generator.run(diff)

Constant Summary collapse

LINE_NUM_RE =

Extracts the line number info for a given diff section

/^@@ [+-]([0-9]+)(?:,([0-9]+))? [+-]([0-9]+)(?:,([0-9]+))? @@/
LINE_TYPES = 
{'+' => :add, '-' => :rem, ' ' => :unmod, '\\' => :nonewline}

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Generator

Returns a new instance of Generator.



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# File 'lib/diff/display/unified/generator.rb', line 32

def initialize
  @buffer         = []
  @line_type      = nil
  @prev_line_type = nil
  @offset         = [0, 0]
  @data = Data.new
  self
end

Class Method Details

.run(udiff) ⇒ Object

Runs the generator on a diff and returns a Data object

Raises:

  • (ArgumentError) 


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# File 'lib/diff/display/unified/generator.rb', line 18

def self.run(udiff)
  raise ArgumentError, "Object must be enumerable" unless udiff.respond_to?(:each_line)
  generator = new
  udiff.each_line do |line|
    begin
      generator.process(line.chomp)
    rescue ArgumentError => e
      e.message =~ /^invalid byte sequence/ ? next : raise(e)
    end
  end
  generator.finish
  generator.data
end

Instance Method Details

#data ⇒ Object

Finishes up with the generation and returns the Data object (could probably use a better name…maybe just #data?)



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# File 'lib/diff/display/unified/generator.rb', line 43

def data
  @data
end

#finish ⇒ Object

This method is called once the generator is done with the unified diff. It is a finalizer of sorts. By the time it is called all data has been collected and processed.



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# File 'lib/diff/display/unified/generator.rb', line 50

def finish
  # certain things could be set now that processing is done
  #identify_block
end

#process(line) ⇒ Object 



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# File 'lib/diff/display/unified/generator.rb', line 55

def process(line)      
  if is_header_line?(line)
    push Block.header
    current_block << Line.header(line)
    return
  end
  
  if line =~ LINE_NUM_RE
    push Block.header
    current_block << Line.header(line)
    add_separator unless @offset[0].zero?
    @line_type = nil
    @offset    = Array.new(2) { $3.to_i - 1 }
    return
  end
  
  @line_type, line = LINE_TYPES[car(line)], cdr(line)
  
  if @line_type == :add && @prev_line_type == :rem
    @offset[0] -= 1
    @buffer.push current_block.pop
    @buffer.push line
    process_block(:mod, false)
    return
  end
  
  if LINE_TYPES.values.include?(@line_type)
    @buffer.push(line.to_s)
    process_block(@line_type, true)
  end
  
end