The Shape of Code

In popular mythology, Grace Hopper is a programmer who wrote one of the first compilers. I think the reality is that Hopper did some programming, but quickly moved into management; a common career path for freshly minted PhDs and older people entering computing (Hopper was in her 40s when she started); her compiler management work occurred well after many other compilers had been written.

What is the evidence?

Hopper is closely associated with Cobol. There is a lot of evidence for at least 28 compilers in 1957, well before the first Cobol compiler (can a compiler written after the first 28 be called one of the first?)

The A-0 tool, which Hopper worked on as a programmer in 1951-52, has been called a compiler. However, the definition of Compile used sounds like today’s assembler and the definition of Assemble used sounds like today’s link-loader (also see: section 7 of Digital Computers – Advanced Coding Techniques for Hopper’s description of what A-2, a later version, did).

The ACM’s First Glossary of Programming Terminology, produced by a committee chaired by Hopper in June 1954.

Routine – a set of coded instructions arranged in proper sequence to direct the computer to perform a desired operation or series of operations. See also Subroutine.

Compiler (Compiling Routine) – an executive routine which, before the desired computation is started, translates a program expressed in pseudo-code into machine code (or into another pseudo-code for further translation by an interpreter). In accomplishing the translation, the compiler may be required to:

…

Assemble – to integrate the subroutines (supplied, selected, or generated) into the main routine, i.e., to:

    Adapt – to specialize to the task at hand by means of preset parameters.

    Orient – to change relative and symbolic addresses to absolute form.

    Incorporate – to place in storage.

Hopper’s name is associated with work on the MATH-MATIC and ARITH-MATIC Systems, but her name does not appear in the list of people who wrote the manual in 1957. A programmer working on these systems is likely to have been involved in producing the manual.

After the A-0 work, all of Hopper’s papers relate to talks she gave, committees she sat on and teams she led, i.e., the profile of a manager.