Class: Diff::LCS::ContextChange

Inherits:
Object
  • Object
show all
Includes:
Comparable, ChangeTypeTests
Defined in:
lib/diff/lcs/change.rb

Overview

Represents a contextual change. Contains the position and values of the elements in the old and the new sequenced enumerables as well as the action taken.

Instance Attribute Summary (collapse)

Class Method Summary (collapse)

Instance Method Summary (collapse)

Methods included from ChangeTypeTests

#adding?, #changed?, #deleting?, #finished_a?, #finished_b?, #unchanged?

Constructor Details

- (ContextChange) initialize(action, old_position, old_element, new_position, new_element)

A new instance of ContextChange



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# File 'lib/diff/lcs/change.rb', line 117

def initialize(action, old_position, old_element, new_position, new_element)
  @action = action
  @old_position = old_position
  @old_element = old_element
  @new_position = new_position
  @new_element = new_element
end

Instance Attribute Details

- (Object) action (readonly)

Returns the action this Change represents. Can be '+' (#adding?), '-' (#deleting?), '=' (#unchanged?), # or '!' (#changed?). When created by Diff::LCS#diff or Diff::LCS#sdiff, it may also be '>' (#finished_a?) or '<' (#finished_b?).



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# File 'lib/diff/lcs/change.rb', line 88

def action
  @action
end

- (Object) new_element (readonly)

Returns the value of attribute new_element



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# File 'lib/diff/lcs/change.rb', line 92

def new_element
  @new_element
end

- (Object) new_position (readonly)

Returns the value of attribute new_position



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# File 'lib/diff/lcs/change.rb', line 91

def new_position
  @new_position
end

- (Object) old_element (readonly)

Returns the value of attribute old_element



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# File 'lib/diff/lcs/change.rb', line 90

def old_element
  @old_element
end

- (Object) old_position (readonly)

Returns the value of attribute old_position



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# File 'lib/diff/lcs/change.rb', line 89

def old_position
  @old_position
end

Class Method Details

+ (Object) from_a(arr)

Creates a ContextChange from an array produced by ContextChange#to_a.



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# File 'lib/diff/lcs/change.rb', line 130

def self.from_a(arr)
  if arr.size == 5
    Diff::LCS::ContextChange.new(arr[0], arr[1], arr[2], arr[3], arr[4])
  else
    Diff::LCS::ContextChange.new(arr[0], arr[1][0], arr[1][1], arr[2][0],
                                 arr[2][1])
  end
end

+ (Object) simplify(event)

Simplifies a context change for use in some diff callbacks. '<' actions are converted to '-' and '>' actions are converted to '+'.



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# File 'lib/diff/lcs/change.rb', line 141

def self.simplify(event)
  ea = event.to_a

  case ea[0]
  when '-'
    ea[2][1] = nil
  when '<'
    ea[0] = '-'
    ea[2][1] = nil
  when '+'
    ea[1][1] = nil
  when '>'
    ea[0] = '+'
    ea[1][1] = nil
  end

  Diff::LCS::ContextChange.from_a(ea)
end

Instance Method Details

- (Object) <=>(other) 



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# File 'lib/diff/lcs/change.rb', line 108

def <=>(other)
  r = @action <=> other.action
  r = @old_position <=> other.old_position if r.zero?
  r = @new_position <=> other.new_position if r.zero?
  r = @old_element <=> other.old_element if r.zero?
  r = @new_element <=> other.new_element if r.zero?
  r
end

- (Object) ==(other) 



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# File 'lib/diff/lcs/change.rb', line 96

def ==(other)
  (@action == other.action) and
  (@old_position == other.old_position) and
  (@new_position == other.new_position) and
  (@old_element == other.old_element) and
  (@new_element == other.new_element)
end

- (Object) inspect(*args) 



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# File 'lib/diff/lcs/change.rb', line 104

def inspect(*args)
  %Q(#<#{self.class.name}:#{__id__} @action=#{action} positions=#{old_position},#{new_position} elements=#{old_element.inspect},#{new_element.inspect}>)
end

- (Object) to_a 



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# File 'lib/diff/lcs/change.rb', line 125

def to_a
  [@action, [@old_position, @old_element], [@new_position, @new_element]]
end