class Diff::LCS::Block

deletes a single item. Used by bin/ldiff.
Basically, this is just a list of changes, where each change adds or
A block is an operation removing, adding, or changing a group of items.

def diff_size 

def diff_size
  @insert.size - @remove.size
end

def initialize(chunk) 

def initialize(chunk)
  @changes = []
  @insert = []
  @remove = []
  chunk.each do |item|
    @changes << item
    @remove << item if item.deleting?
    @insert << item if item.adding?
  end
end

def op 

def op
  case [@remove.empty?, @insert.empty?]
  when [false, false]
    "!"
  when [false, true]
    "-"
  when [true, false]
    "+"
  else # [true, true]
    "^"
  end
end