在 rust 社区的慷慨帮助下,我设法获得了使用托管指针组装的拓扑数据结构的基础。这很好地结合在一起,总的来说,我对 Rust 感到非常兴奋。然后我读了这篇文章(这似乎是一个合理的计划),它启发了我回溯并尝试尽可能只使用拥有的指针重新组装它。
这是使用托管指针的工作版本:
struct Dart<T> {
alpha: ~[@mut Dart<T>],
embed: ~[@mut T],
tagged: bool
}
impl<T> Dart<T> {
pub fn new(dim: uint) -> @mut Dart<T> {
let mut dart = @mut Dart{alpha: ~[], embed: ~[], tagged: false};
dart.alpha = vec::from_elem(dim, dart);
return dart;
}
pub fn get_dim(&self) -> uint {
return self.alpha.len();
}
pub fn traverse(@mut self, invs: &[uint], f: &fn(&Dart<T>)) {
let dim = self.get_dim();
for invs.each |i| {if *i >= dim {return}}; //test bounds on invs vec
if invs.len() == 2 {
let spread:int = int::abs(invs[1] as int - invs[0] as int);
if spread == 1 { //simple loop
let mut dart = self;
let mut i = invs[0];
while !dart.tagged {
dart.tagged = true;
f(dart);
dart = dart.alpha[i];
if i == invs[0] {i = invs[1];}
else {i == invs[0];}
} }
// else if spread == 2 { // max 4 cells traversed
// }
}
else {
let mut stack = ~[self];
self.tagged = true;
while !stack.is_empty() {
let mut dart = stack.pop();
f(dart);
for invs.each |i| {
if !dart.alpha[*i].tagged {
dart.alpha[*i].tagged = true;
stack.push(dart);
} } } } } }
在追逐生命周期错误几个小时后,我得出的结论是,由于循环性质(没有像我被警告的那样打结),拥有指针甚至可能无法做到这一点。我在这方面的微弱尝试如下。我的问题是,这种结构是否可以在不借助托管指针的情况下实现?如果不是,上面的代码是否被认为是合理的“生锈”?(惯用的锈)。谢谢。
struct GMap<'self,T> {
dim: uint,
darts: ~[~Dart<'self,T>]
}
struct Dart<'self,T> {
alpha: ~[&'self mut Dart<'self, T>],
embed: ~[&'self mut T],
tagged: bool
}
impl<'self, T> GMap<'self, T> {
pub fn new_dart(&'self mut self) {
let mut dart = ~Dart{alpha: ~[], embed: ~[], tagged: false};
let dartRef: &'self mut Dart<'self, T> = dart;
dartRef.alpha = vec::from_elem(self.dim, copy dartRef);
self.darts.push(dart);
}
}