From: Doug McIlroy Date: Fri, 07 Dec 2018 22:54:17 -0500 To: tuhs@tuhs.org Subject: Re: [TUHS] C comments Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Very little in language design is so contentious as comment conventions. C borrowed the PL/I convention, which had the virtue of being useful for both in-line and interlinear comments, and did not necessitate marking every line of a long comment. Nobody in the Unix lab had had much experience with the convention, despite having worked on Multics for which PL/I was the implementation language. And how did PL/I get the convention? It was proposed by Paul Rogoway at the first NPL (as it was then called) design-committee meeting that I attended. Apparently the topic had been debated for some while before and people were tired of the subject. Paul was more firmly committed to his new idea than others were to old options, so it carried more or less by default. Besides, there was a much more interesting topic on the agenda. Between the previous meeting and that one, George Radin had revamped the entire NPL proposal from mainly Fortran-like syntax to Algol-like. That was heady enough stuff to divert people's attention from comments. As for inexperiece. The comment conventions of previous languages had not fostered the practice of commenting out code. So that idea, which is the main impetus for nesting comments, was not in anybody's mind at the time. Had it been, nesting might well have carried the day. It probably could have been changed before 1980, but thereafter there were too many C compilers. Then standards introduced even more conservatism. Perhaps Ken can remember whether the notion was ever seriously considered. Doug