def operations
position_in_old = position_in_new = 0
operations = []
matches = matching_blocks
matches << Match.new(@old_words.length, @new_words.length, 0)
matches.each_with_index do |match, i|
match_starts_at_current_position_in_old = (position_in_old == match.start_in_old)
match_starts_at_current_position_in_new = (position_in_new == match.start_in_new)
action_upto_match_positions =
case [match_starts_at_current_position_in_old, match_starts_at_current_position_in_new]
when [false, false]
:replace
when [true, false]
:insert
when [false, true]
:delete
else
:none
end
if action_upto_match_positions != :none
operation_upto_match_positions =
Operation.new(action_upto_match_positions,
position_in_old, match.start_in_old,
position_in_new, match.start_in_new)
operations << operation_upto_match_positions
end
if match.size != 0
match_operation = Operation.new(:equal,
match.start_in_old, match.end_in_old,
match.start_in_new, match.end_in_new)
operations << match_operation
end
position_in_old = match.end_in_old
position_in_new = match.end_in_new
end
operations
end