Were There Programming Languages Before Compilers? [closed]

Question

Obviously there must have been a programming language to write a compiler for, but did people used to write in say COBOL (or whatever) and then hand compile it to assembly or was it all written in assembly until someone thought of a higher language? Thanks, ell.

Answer 1

The notion of programming languages and compilers evolved hand-in-hand. Grace Hopper is generally credited with having developed the first compiler:

In 1952, Hopper completed her first compiler (for Sperry-Rand computer), known as the A-0 System. As she said later, she did this, because she was lazy and hoped that the programmer may return to being a mathematician.

The A-0 System actually was a set of instructions that could translate symbolic mathematical code into machine language. In producing A-0, Hopper took all the subroutines she had been collecting over the years and put them on a tape. Each routine was given a call number, so that it the machine could find it on the tape. As described by Hopper—“All I had to do was to write down a set of call numbers, let the computer find them on the tape, bring them over and do the additions. This was the first compiler.”

Source: http://history-computer.com/ModernComputer/Software/FirstCompiler.html

As stated on Wikipedia, “The A-0 functioned more as a loader or linker than the modern notion of a compiler.” (It kind of literally compiled together subroutines, hence the name.) I don't have any more detailed references on hand at the moment, but you can imagine that the input that A-0 and similar programs could process evolved incrementally to be more complex—more like what is now called a “high-level programming language”—with compilers taking on more of their modern function as translators and not mere compilers of code (but the name stuck).

You can probably find more details in the transcript of the keynote address that Hopper gave at the first “History of Programming Languages” conference, as published in the HOPL I conference proceedings. If I remember well, she describes there how things evolved from A-0 to her later work that also inspired COBOL; but I didn't re-read the article yet myself.

It's interesting and amusing to note that Hopper says she encountered resistance to the idea of a program that wrote programs:

“I had a running compiler, and nobody would touch it because, they carefully told me, computers could only do arithmetic; they could not do programs.”

Source: http://www.computinghistory.org.uk/det/5487/Grace%20Hopper%20completes%20the%20A-0%20Compiler