I must formally disagree: 500 lines is about how you can read and comprehend a program. 500 lines fits in a single file in virtually any programming language (yes, you can put multiple classes in a single *.java file). And if you make use of libraries which allow to write 500 lines of high order instructions steering a vastly complex machinery, even better! This allows the 500 lines to be very expressive. I really like the idea because it puts emphasis onto a well written documentation which explains concepts while the code is very breve. Shorter code can increase the probability that bugs are found because it is probably more frequently read by other people.
> 500 lines is about how you can read and comprehend a program.
(With the exception of languages that are idiomatically horizontal, such as Forth or APL, where a 500-line program sounds about as reassuring as a 500-line mathematics paper, and is probably about as dense. But none of the programs in that book use one of those.)
