Re:Understand Go pointers
by int_19h on Wednesday April 26, 2017 @11:08PM
(#14208895)
I can't help but wonder if the reason why Pascal pointers feel less complicated because they're more constrained, or because of the syntax, or both.
On the constrained part of things, there's no pointer arithmetic, and in Standard Pascal, there's no "address of" operator at all - a pointer can only point at dynamically allocated memory block, not at global or local variable, or some memory location inside another block. Consequently, there's also no pointer arithmetic. This is sufficient to make linked lists and other similar data structures, but also makes the concept much more opaque compared to C (i.e. it's less obvious that it's really a numeric address).
On the syntax part, I think the big problem with C is that the moment you start dealing with pointers, the arcane rules for declarator precedence are in play. Pascal, OTOH, has a very regular type syntax, which in case of pointers is also easier to read - you just read ^ as "pointer to", and so ^integer is "pointer to integer". Same thing for dereferencing - again it's ^, but there you read ^ as "points to", and so a dereference like x^ becomes "what x points to". And there's also no confusion with any other operator, since ^ is reserved for pointers alone, and it has a fairly obvious mnemonic to it.
On the constrained part of things, there's no pointer arithmetic, and in Standard Pascal, there's no "address of" operator at all - a pointer can only point at dynamically allocated memory block, not at global or local variable, or some memory location inside another block. Consequently, there's also no pointer arithmetic. This is sufficient to make linked lists and other similar data structures, but also makes the concept much more opaque compared to C (i.e. it's less obvious that it's really a numeric address).
On the syntax part, I think the big problem with C is that the moment you start dealing with pointers, the arcane rules for declarator precedence are in play. Pascal, OTOH, has a very regular type syntax, which in case of pointers is also easier to read - you just read ^ as "pointer to", and so ^integer is "pointer to integer". Same thing for dereferencing - again it's ^, but there you read ^ as "points to", and so a dereference like x^ becomes "what x points to". And there's also no confusion with any other operator, since ^ is reserved for pointers alone, and it has a fairly obvious mnemonic to it.