Struct SoaAst 

pub struct SoaAst {
    pub tags: Vec<NodeTag>,
    pub data: Vec<NodeData>,
    pub extra: Vec<u32>,
    pub items: Vec<NodeIndex>,
}

Struct-of-Arrays AST representation.

This is the new SOA-based AST that will replace the tree-based Ast. During migration (Phases 2-3), both representations will coexist.

Design principles:

• All nodes stored in parallel arrays (tags, data, extra)
• Nodes reference children by index, not pointers
• Single allocation for entire AST (better cache locality)
• Cheap cloning (just clone Arc, not deep copy)

See docs/designs/soa-ast-layout.md for full design.

Fields

tags: Vec<NodeTag>

Node tags (what kind of node is at each index).

Index i contains the tag for node NodeIndex(i). Length of this vec == number of nodes in the AST.

data: Vec<NodeData>

Node data (main_token + lhs + rhs for each node).

Parallel array to tags - tags[i] and data[i] together describe node i.

extra: Vec<u32>

Extra data storage for nodes with >2 children.

Nodes that can’t fit their data in lhs+rhs store additional data here. The lhs or rhs field contains an index into this array.

Layout is node-type specific - see NodeTag documentation.

items: Vec<NodeIndex>

Root nodes (top-level items in the source file).

These are the entry points for traversing the AST. Each element is a NodeIndex pointing to a Function, StructDecl, etc.

Implementations

impl SoaAst

pub fn new() -> Self

Create a new empty SOA AST.

pub fn with_capacity(nodes: usize, extra: usize) -> Self

Create a new SOA AST with pre-allocated capacity.

pub fn node_tag(&self, idx: NodeIndex) -> NodeTag

Get the tag for a node.

pub fn node_data(&self, idx: NodeIndex) -> NodeData

Get the data for a node.

pub fn main_token(&self, idx: NodeIndex) -> u32

Get the main token for a node.

pub fn node_count(&self) -> usize

Get the number of nodes in the AST.

pub fn extra_slice(&self, start: usize, len: usize) -> &[u32]

Get a slice of the extra data array.

pub fn int_value(&self, idx: NodeIndex) -> u64

Get the value of an integer literal.

pub fn bool_value(&self, idx: NodeIndex) -> bool

Get the boolean value of a boolean literal.

pub fn string_spur(&self, idx: NodeIndex) -> Spur

Get the string spur of a string literal.

pub fn ident_spur(&self, idx: NodeIndex) -> Spur

Get the identifier spur.

pub fn binary_operands(&self, idx: NodeIndex) -> (NodeIndex, NodeIndex)

Get the operands of a binary expression.

pub fn unary_operand(&self, idx: NodeIndex) -> NodeIndex

Get the operand of a unary expression.

pub fn unary_op(&self, idx: NodeIndex) -> UnaryOp

Get the operator kind of a unary expression.

Trait Implementations

impl Clone for SoaAst

fn clone(&self) -> SoaAst

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SoaAst

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

Formats the value using the given formatter.

impl Default for SoaAst

fn default() -> Self

Returns the “default value” for a type.