function debug () {
	if [ -n "$DEBUG" ]; then
		echo "$1"
	fi
}

function debug_inline () {
	if [ -n "$DEBUG" ]; then
		printf "$1"
	fi
}

function error_and_exit () {
	echo $1 || "error"
	exit 1
}

function assert_arg () {
	arg=$1

	if [ -z "$arg" ]; then
		return 1
	fi
	return 0
}