The Shape of Code

Who wrote the early compilers, when did they do it, and what were the languages compiled?

Answering these questions requires defining what we mean by ‘compiler’ and deciding what counts as a language.

Donald Knuth does a masterful job of covering the early development of programming languages. People were writing programs in high level languages well before the 1950s, and Konrad Zuse is the forgotten pioneer from the 1940s (it did not help that Germany had just lost a war and people were not inclined to given German’s much public credit).

What is the distinction between a compiler and an assembler? Some early ‘high-level’ languages look distinctly low-level from our much later perspective; some assemblers support fancy subroutine and macro facilities that give them a high-level feel.

Glennie’s Autocode is from 1952 and depending on where the compiler/assembler line is drawn might be considered a contender for the first compiler. The team led by Grace Hopper produced A-0, a fancy link-loader, in 1952; they called it a compiler, but today we would not consider it to be one.

Talking of Grace Hopper, from a biography of her technical contributions she sounds like a person who could be technical but chose to be management.

Fortran and Cobol hog the limelight of early compiler history.

Work on the first Fortran compiler started in the summer of 1954 and was completed 2.5 years later, say the beginning of 1957. A very solid claim to being the first compiler (assuming Autocode and A-0 are not considered to be compilers).

Compilers were created for Algol 58 in 1958 (a long dead language implemented in Germany with the war still fresh in people’s minds; not a recipe for wide publicity) and 1960 (perhaps the first one-man-band implemented compiler; written by Knuth, an American, but still a long dead language). The 1958 implementation sounds like it has a good claim to being the second compiler after the Fortran compiler.

In December 1960 there were at least two Cobol compilers in existence (one of which was created by a team containing Grace Hopper in a management capacity). I think the glory attached to early Cobol compiler work is the result of having a female lead involved in the development team of one of these compilers. Why isn’t the other Cobol compiler ever mentioned? Why is the Algol 58 compiler implementation that occurred before the Cobol compiler ever mentioned?

What were the early books on compiler writing?

“Algol 60 Implementation” by Russell and Randell (from 1964) still appears surprisingly modern.

Principles of Compiler Design, the “Dragon book”, came out in 1977 and was about the only easily obtainable compiler book for many years. The first half dealt with the theory of parser generators (the audience was CS undergraduates and parser generation used to be a very trendy topic with umpteen PhD thesis written about it); the book morphed into Compilers: Principles, Techniques, and Tools. Old-timers will reminisce about how their copy of the book has a green dragon on the front, rather than the red dragon on later, trendier (with less parser theory and more code generation) editions.