Don't confuse "premature optimization" with "no optimization". As you and jrockway wrote, there certainly are more exotic data structures that are more appropr

Don't confuse "premature optimization" with "no optimization". As you and jrockway wrote, there certainly are more exotic data structures that are more appropriate for a text editor, but until there is enough of a text editor to do actual tests with, then choosing one of the options is premature. From what I read, the programmer's intent was not to write the most efficient editor, but to write an editor and see how the internal program structure will evolve as it becomes more efficient and/or feature rich. That knowledge and experience is sometimes more valuable then knowing what data structure to use.