global

:yields diff changes:
#finish, it will be called.
initialise it. If the +callbacks+ object (possibly initialised) responds to
Class argument is provided for +callbacks+, #diff will attempt to
behaviour may be implemented with Diff::LCS::ContextDiffCallbacks. If a
See Diff::LCS::DiffCallbacks for the default behaviour. An alternate

changes.
turn the first sequence into the second, and returns a description of these
#diff computes the smallest set of additions and deletions necessary to

def diff(seq1, seq2, callbacks = nil, &block) # :yields diff changes:
  diff_traversal(:diff, seq1, seq2, callbacks || Diff::LCS::DiffCallbacks, &block)
end