Question about the let statement

> why do I need a var seq (hidden pointer to a variable on the stack) in order > to change its items? You don't, `var openArray` does what you're asking for.

Question about the let statement

the reason is, because other parts of the object aren't stored on the heap (length and depending on the runtime also capacity iirc). Another reason is that seqs behave exactly like regular non heap objects in that they have copy instead of reference semantics. So the internal pointer of a seq i

Question about the let statement

For `seq`, two levels of mutability (pointer and item) are mixed in one (either both mutable, or both immutable). For `ptr` and `ref`, a level of mutability is not implemented, as the object pointed to is always considered mutable.

Question about the let statement

For me the behavior of `ptr` is more correct than that of `seq`. I could never understand that, if the items of a `seq` are stored on the heap, why do I need a `var seq` (hidden pointer to a variable on the stack) in order to change its items?

Question about the let statement

Pointers are inconsistent with `seq` just like `int` (many values) is "inconsistent" with `bool` (only two values). An inconsistency usually goes beyond "I connected two different things in my head and they are different, ergo inconsistent". There is also `var openArray` (mutable, not appendable

Question about the let statement

If viewing pointers as values, it's easy to understand this behavior, and I believe it's correct. However most people don't understand it that way. Nim only distinguishs between `ptr T` (immutable pointer) and `var ptr T` (mutable pointer), but not `var ptr T` (mutable pointer to an object) and

Question about the let statement

Inside a "strict" func the mutations via pointers are forbidden.

Question about the let statement

If a `ref`/`ptr` is declared with `let`, then the pointer/reference is itself immutable (meaning it cannot point to somewhere else), however the variable it points to is still mutable, as the variable pointed to is not a part of the `let` variable. let p: ptr int = nil var a: i

Question about the let statement

Thanks, that sounds reasonable.

Question about the let statement

Mutability is allowed for `let` values if they are behind `ref`/`ptr`. In neo, Vector/Matrix are both `ref object`s, and their `[]=` does not require that they are `var Vector`/`var Matrix` (which they could, in which case this code would not compile).

Question about the let statement

As I understand the let keyword introduces an immutable variable, so you can't change it after initialization. So for example let x = @[1,2,3] x[0] = 5 Run wouldn't work. Yesterday I discovered the library neo, which can be used to create matrices and vectors. B