gnu@sun.uucp (John Gilmore) (07/17/85)
Bill Crews of Cyb Systems said: > My most heavily-used language before learning C was PL/I, which looks > much like C *structurally*, BUT without the side effects such as imbedded > assignments that C has. I'm not sure what "side effects" C has that PL/I doesn't have. It's certainly true that you can call a function from anywhere in an expression, and the function can have arbitrary side effects. As I recall, PL/I was one of the first languages IBM tried to design for optimization, and there were very tight reins on what you could assume about order of evaluation of expressions. C is probably a bit looser, but it's been long enough that I can't recall the difference without a manual. C does have a few builtin functions that produce side effects, but PL/I had pass-by-reference, which means any user-written function can do that to its arguments.