Struct Node 

pub struct Node {
    pub head: Head,
    pub args: Vec<Node>,
    pub applied: bool,
    pub meta: Meta,
}

Fields

head: Head

args: Vec<Node>

applied: bool

Whether this node was written as an application.

§2.2’s model has args: list[Node], which leaves (params) and params indistinguishable — and an empty parameter list is not the same thing as a reference to a variable called params. Elixir solves this by giving a variable nil args where a call has a list; this is the same distinction with a cheaper representation.

meta: Meta

Implementations

impl Node

pub fn sym(name: impl AsRef<str>, span: Span) -> Node

pub fn symbol(sym: Symbol, span: Span) -> Node

pub fn lit(lit: Lit, span: Span) -> Node

pub fn form(head: impl AsRef<str>, args: Vec<Node>, span: Span) -> Node

pub fn form_sym(head: Symbol, args: Vec<Node>, span: Span) -> Node

pub fn span(&self) -> Span

pub fn head_sym(&self) -> Option<&Symbol>

pub fn head_name(&self) -> Option<&str>

pub fn as_lit(&self) -> Option<&Lit>

pub fn as_str_lit(&self) -> Option<&str>

pub fn as_keyword(&self) -> Option<&str>

pub fn as_var(&self) -> Option<&Symbol>

A bare identifier: symbol head, not applied.

pub fn is_form(&self, head: &str) -> bool

An application with this exact head name — (params) counts, a bare params does not.

pub fn has_head(&self, head: &str) -> bool

(head ...) or a bare head.

pub fn arg(&self, i: usize) -> Option<&Node>

pub fn structurally_eq(&self, other: &Node) -> bool

Structural equality ignoring spans and expansion chains — what tests and the round-trip property compare, since formatting is explicitly not part of a Node’s identity.

pub fn map_symbols(&self, f: &mut impl FnMut(&Symbol) -> Symbol) -> Node

Rewrite every symbol in the tree. The expander’s workhorse.

pub fn add_scope(&self, s: Scope) -> Node

Add a scope to every symbol in the tree.

pub fn flip_scope(&self, s: Scope) -> Node

Flip a scope on every symbol in the tree (see ScopeSet::flip).

pub fn with_expansion(&self, name: Arc<str>, at: Span) -> Node

Record that this subtree came out of a macro, for §4.5’s expansion chain in diagnostics.

pub fn node_count(&self) -> usize

Trait Implementations

impl Clone for Node

fn clone(&self) -> Node

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Node

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

Formats the value using the given formatter.

impl PartialEq for Node

Structural equality, ignoring spans and expansion chains.

Salsa needs Eq to decide whether a re-executed query actually produced a different value, and formatting is explicitly not part of a Node’s identity (§2.2) — so equality is exactly Node::structurally_eq, and a re-parse that moved a span does not invalidate anything downstream.

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Node