Show me your flowchart and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won’t usually need your flowchart; it’ll be obvious.
Show me your code and conceal your data structures, and I shall continue to be mystified. Show me your data structures, and I won’t usually need your code; it’ll be obvious.
Show me your function bodies and conceal your types, and I shall continue to be mystified. Show me your types, and I won’t usually need your function bodies; they’ll be obvious.
– Maybe Fred Brookes or Eric Raymond, if they’d been strongly typed functional programmers
(Thanks to Jeremy Gibbons for providing the Eric Raymond citation)