Comment by tsimionescu
10 months ago
> C++ really took failure modes to the next level. My favorites is "a = b/*c;" Is that "a equals b divided by value pointed at by c" or "a equals b" with a comment?
That is a really bizarre comment, especially including a comment that is perfectly valid K&R C, and just as "ambiguous" in that. The answer is of course that it is an assignment of the value b to a variable called a, followed by a comment. "/*" is always the start of a block comment.
Since C99 (and since forever in C++) there is also the new style comment, //, for commenting out the rest of the line, and this in fact broke certain older C programs (`a = b//* my comment*/ c;` used to mean a = b / c; in C89, and means `a = b` in C++ or C99).
Well, it is kinda weird to take what would otherwise be perfectly legitimate and meaningful syntax and make it a comment. E.g. Pascal uses (* *) instead, and there's no other construct in the language where those can legitimately appear in this order.
Sure, but it's still a choice that C made, long before C++, so it's bizarre to see it in reference to how much worse C++ is.
As for the actual syntax itself, I do wonder why they didn't use ## or #{ }# or something similar, since # was only being used for the preprocessor, whereas / and * were much more common.
/* */ is a PL/I thing that somehow ended up in B. I suspect that Ritchie just wanted multiline comments (which BCPL didn't have - it only had // line comments), and just grabbed the syntax from another language he was familiar with without much consideration.
Or maybe he just didn't care about having to use whitespace to disambiguate. The other piece of similarly ambiguous syntax in B is the compound assignment, which was =+ =- =* =/ rather than the more familiar C-style += etc. So a=+a and a= +a would have different meaning.