Struct ChildList 

pub struct ChildList<Id>
where
    Id: Copy + Default,
{ /* private fields */ }

子节点容器：≤3 个孩子零堆分配（AST 绝大多数节点—— Binary/Assign=2、Member/MethodRef=1、VarDecl≤1、Literal=0…… 大语料 malloc 采样的剩余大头是每节点一次 Vec 堆分配）； ≥4 溢出到堆。Block/Call 大参数列表溢出属预期路径。

Id 需 Copy + Default（Default 作为空槽哨兵值；语言侧通常用 u32::MAX 之类的非法下标 newtype）。

Implementations

impl<Id> ChildList<Id>

where Id: Copy + Default,

pub fn new() -> ChildList<Id>

pub fn from_vec(v: Vec<Id>) -> ChildList<Id>

pub fn as_slice(&self) -> &[Id]

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn set(&mut self, index: usize, new: Id)

按索引替换（保持同一形态）。

pub fn remove(&mut self, index: usize)

移除一个孩子（内联区左移；堆走 Vec::remove）。

pub fn splice(&mut self, index: usize, remove: usize, insert: Vec<Id>)

区间替换（Splice 语义：删 [index, index+remove) 插 insert）。

Trait Implementations

impl<Id> Clone for ChildList<Id>

where Id: Clone + Copy + Default,

fn clone(&self) -> ChildList<Id>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<Id> Debug for ChildList<Id>

where Id: Debug + Copy + Default,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<Id> Default for ChildList<Id>

where Id: Copy + Default,

fn default() -> ChildList<Id>

Returns the “default value” for a type.

impl<Id> PartialEq for ChildList<Id>

where Id: Copy + Default + PartialEq,

fn eq(&self, other: &ChildList<Id>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.