Re:Mistakes with Rust smart pointers: when Deref goes wrong
by mananaysiempre on Monday July 10, 2023 @07:54AM
(#36665074)
Object Pascal strikes again: if a: ^record ... end is a pointer to a record, then a^ is the pointed-to record as a value and a^.b is the way you access a field of it.
Incidentally, the authors of Go were asked why they didn’t use a postfix dereference when Sethi noted[1] back in 1981 that C syntax would have been simpler that way, was quoted in Ritchie’s 1993 retrospective[2] on that point, and even their own blog post on declaration syntax pointed out that possibility[3], but IIRC the answer amounted to “but then we wouldn’t have gotten those sweet, sweet C-bandwagon popularity points”.
(I also cannot help calling out “Language X” here: One nice approach that nevertheless basically forces implicit dereferencing is that of Algon-68, where all values are constant values; the way to declare a mutable variable is to declare a pointer—a constant value—to a mutable cell; and the way to make the whole thing bearable is to have the compiler infer the minimum possible amount of dereferencing in an expression from the types of the values involved. Then of course it becomes impossible to infer the types, so the ML family goes with the inconvenient dereferencing, and you end up not really using a lot of mutability in ML.)
Incidentally, the authors of Go were asked why they didn’t use a postfix dereference when Sethi noted[1] back in 1981 that C syntax would have been simpler that way, was quoted in Ritchie’s 1993 retrospective[2] on that point, and even their own blog post on declaration syntax pointed out that possibility[3], but IIRC the answer amounted to “but then we wouldn’t have gotten those sweet, sweet C-bandwagon popularity points”.
(I also cannot help calling out “Language X” here: One nice approach that nevertheless basically forces implicit dereferencing is that of Algon-68, where all values are constant values; the way to declare a mutable variable is to declare a pointer—a constant value—to a mutable cell; and the way to make the whole thing bearable is to have the compiler infer the minimum possible amount of dereferencing in an expression from the types of the values involved. Then of course it becomes impossible to infer the types, so the ML family goes with the inconvenient dereferencing, and you end up not really using a lot of mutability in ML.)
[1] https://dx.doi.org/10.1002/spe.4380110606
[2] https://dx.doi.org/10.1145/154766.155580
[3] https://go.dev/blog/declaration-syntax