John Backus's Turing Award Lecture
John Backus's Turing Award Lecture was a watershed for the
programming-language community because the inventor of FORTRAN, which
was the dominant programming language of the day, stepped forward and
said that the main stream of programming practice was flowing in a
most unproductive direction.
His lecture "Can Programming Be Liberated From the von Neumann Style?"
was developed into a
fairly technical paper
which opened the floodgates for a torrent of intellectual activity
that continues to this day.
While Backus's message remains as relevant as ever (simply substitute
"object-oriented languages" for "conventional languages"), the
technical work has worn less well.
Backus's original proposals, while tremendously important to the
development of a young field, are now taken for granted.
Much of the most exciting work builds on two ideas brought to fruition
after Backus's lecture:
polymorphic type systems with type inference,
and algebraic data types
with pattern matching.
Thanks in part to a lifetime of work by Richard Bird,
algebraic reasoning techniques in Section 12
have been developed to a point where they are much more readable and
can be routinely applied to
they are especially useful for developing efficient
But like other formal techniques, they are not scaled up
to write whole systems.
Functional programming has moved away from the point-free style
inspired by APL and shown
in Section 11 of Backus's paper.
Current functional languages deliver more expressive power in a more