function Log2InitState()
	if !exists("b:log_2_cursor") || b:log_2_cursor != col(".") || b:log_2_line != line(".")
		let b:log_2_cursor = col(".")
		let b:log_2_line = line(".")
		let b:log_2_left = 0
		let b:log_2_right = strlen(getline(b:log_2_line))
		let b:log_2_call_stack = ""
	endif
endfunction

function Log2MoveIt(i)
	let b:log_2_cursor = a:i + b:log_2_left + ( (b:log_2_right - b:log_2_left) / 2 )
	call cursor(b:log_2_line, b:log_2_cursor)
endfunction

function Log2StackPush (val)
	let b:log_2_call_stack = b:log_2_call_stack . a:val
endfunction

function Log2StackPop ()
	let ret = strpart(b:log_2_call_stack, strlen(b:log_2_call_stack)-1, 1)
	let b:log_2_call_stack = substitute(b:log_2_call_stack, ".$", "", "")
	return ret
endfunction


function Log2Left()
	call Log2InitState()
	if b:log_2_right - b:log_2_left > 1
		let b:log_2_right = b:log_2_cursor
		call Log2StackPush("l")
		call Log2MoveIt(0)
	endif
endfunction

function Log2Right()
	call Log2InitState()
	if b:log_2_right - b:log_2_left > 1
		let b:log_2_left = b:log_2_cursor
		call Log2StackPush("r")
		call Log2MoveIt(1)
	endif
endfunction

function Log2Backtrack()
	call Log2InitState()

	let popped = Log2StackPop()
	if popped == "r"
		let b:log_2_left = b:log_2_left - (b:log_2_right - b:log_2_left)
		if b:log_2_left < 0
			let b:log_2_left = 0
		endif
	elseif popped == "l"
		let b:log_2_right = b:log_2_right + ( b:log_2_right - b:log_2_left)
		if b:log_2_left > strlen(getline(b:log_2_line))
			let b:log_2_line = strlen(getline(b:log_2_line))
		endif
	else
		let b:log_2_left = 0
		let b:log_2_right = strlen(getline(b:log_2_line))
	endif

	call Log2MoveIt(0)
endfunction