def traverse_sequences(seq1, seq2, callbacks = Diff::LCS::SequenceCallbacks, &block)
matches = Diff::LCS.__lcs(seq1, seq2)
run_finished_a = run_finished_b = false
string = seq1.kind_of?(String)
a_size = seq1.size
b_size = seq2.size
ai = bj = 0
(0 .. matches.size).each do |ii|
b_line = matches[ii]
ax = string ? seq1[ii, 1] : seq1[ii]
bx = string ? seq2[bj, 1] : seq2[bj]
if b_line.nil?
unless ax.nil?
event = Diff::LCS::ContextChange.new('-', ii, ax, bj, bx)
event = yield event if block_given?
callbacks.discard_a(event)
end
else
loop do
break unless bj < b_line
bx = string ? seq2[bj, 1] : seq2[bj]
event = Diff::LCS::ContextChange.new('+', ii, ax, bj, bx)
event = yield event if block_given?
callbacks.discard_b(event)
bj += 1
end
bx = string ? seq2[bj, 1] : seq2[bj]
event = Diff::LCS::ContextChange.new('=', ii, ax, bj, bx)
event = yield event if block_given?
callbacks.match(event)
bj += 1
end
ai = ii
end
ai += 1
while (ai < a_size) or (bj < b_size)
if ai == a_size and bj < b_size
if callbacks.respond_to?(:finished_a) and not run_finished_a
ax = string ? seq1[-1, 1] : seq1[-1]
bx = string ? seq2[bj, 1] : seq2[bj]
event = Diff::LCS::ContextChange.new('>', (a_size - 1), ax, bj, bx)
event = yield event if block_given?
callbacks.finished_a(event)
run_finished_a = true
else
ax = string ? seq1[ai, 1] : seq1[ai]
loop do
bx = string ? seq2[bj, 1] : seq2[bj]
event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
event = yield event if block_given?
callbacks.discard_b(event)
bj += 1
break unless bj < b_size
end
end
end
if bj == b_size and ai < a_size
if callbacks.respond_to?(:finished_b) and not run_finished_b
ax = string ? seq1[ai, 1] : seq1[ai]
bx = string ? seq2[-1, 1] : seq2[-1]
event = Diff::LCS::ContextChange.new('<', ai, ax, (b_size - 1), bx)
event = yield event if block_given?
callbacks.finished_b(event)
run_finished_b = true
else
bx = string ? seq2[bj, 1] : seq2[bj]
loop do
ax = string ? seq1[ai, 1] : seq1[ai]
event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
event = yield event if block_given?
callbacks.discard_a(event)
ai += 1
break unless bj < b_size
end
end
end
if ai < a_size
ax = string ? seq1[ai, 1] : seq1[ai]
bx = string ? seq2[bj, 1] : seq2[bj]
event = Diff::LCS::ContextChange.new('-', ai, ax, bj, bx)
event = yield event if block_given?
callbacks.discard_a(event)
ai += 1
end
if bj < b_size
ax = string ? seq1[ai, 1] : seq1[ai]
bx = string ? seq2[bj, 1] : seq2[bj]
event = Diff::LCS::ContextChange.new('+', ai, ax, bj, bx)
event = yield event if block_given?
callbacks.discard_b(event)
bj += 1
end
end
end