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use std::{mem::size_of, sync::Arc};
use crate::{SmolStr, TextUnit, SyntaxKind};
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct GreenNode {
kind: SyntaxKind,
text_len: TextUnit,
children: Arc<[GreenElement]>,
}
impl GreenNode {
#[inline]
pub fn new(kind: SyntaxKind, children: Box<[GreenElement]>) -> GreenNode {
let text_len = children.iter().map(|x| x.text_len()).sum::<TextUnit>();
GreenNode { kind, text_len, children: children.into() }
}
#[inline]
pub fn kind(&self) -> SyntaxKind {
self.kind
}
#[inline]
pub fn text_len(&self) -> TextUnit {
self.text_len
}
#[inline]
pub fn children(&self) -> &[GreenElement] {
&self.children
}
pub(crate) fn get_child(&self, index: GreenIndex) -> Option<&GreenElement> {
self.children.get(index.0 as usize)
}
pub(crate) fn memory_size_of_subtree(&self) -> usize {
let mut res = size_of::<Self>();
self.children().iter().for_each(|el| match el {
GreenElement::Token(token) => {
res += size_of::<GreenToken>();
if token.text.is_heap_allocated() {
res += token.text.len();
}
}
GreenElement::Node(node) => res += node.memory_size_of_subtree(),
});
res
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub(crate) struct GreenIndex(pub(crate) u32);
impl GreenIndex {
pub(crate) fn next(self) -> GreenIndex {
GreenIndex(self.0 + 1)
}
pub(crate) fn prev(self) -> GreenIndex {
GreenIndex(self.0.wrapping_sub(1))
}
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct GreenToken {
kind: SyntaxKind,
text: SmolStr,
}
impl GreenToken {
#[inline]
pub fn new(kind: SyntaxKind, text: SmolStr) -> GreenToken {
GreenToken { kind, text }
}
#[inline]
pub fn kind(&self) -> SyntaxKind {
self.kind
}
#[inline]
pub fn text(&self) -> &SmolStr {
&self.text
}
#[inline]
pub fn text_len(&self) -> TextUnit {
TextUnit::from_usize(self.text.len())
}
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum GreenElement {
Node(GreenNode),
Token(GreenToken),
}
impl From<GreenNode> for GreenElement {
#[inline]
fn from(node: GreenNode) -> GreenElement {
GreenElement::Node(node)
}
}
impl From<GreenToken> for GreenElement {
#[inline]
fn from(token: GreenToken) -> GreenElement {
GreenElement::Token(token)
}
}
impl GreenElement {
#[inline]
pub fn kind(&self) -> SyntaxKind {
match self {
GreenElement::Node(it) => it.kind(),
GreenElement::Token(it) => it.kind(),
}
}
#[inline]
pub fn text_len(&self) -> TextUnit {
match self {
GreenElement::Node(it) => it.text_len(),
GreenElement::Token(it) => it.text_len(),
}
}
}
#[derive(Clone, Copy, Debug)]
pub struct Checkpoint(usize);
#[derive(Default, Debug)]
pub struct GreenNodeBuilder {
cache: rustc_hash::FxHashSet<GreenNode>,
parents: Vec<(SyntaxKind, usize)>,
children: Vec<GreenElement>,
}
impl GreenNodeBuilder {
#[inline]
pub fn new() -> GreenNodeBuilder {
GreenNodeBuilder::default()
}
#[inline]
pub fn token(&mut self, kind: SyntaxKind, text: SmolStr) {
let token = GreenToken { kind, text };
self.children.push(token.into());
}
#[inline]
pub fn start_node(&mut self, kind: SyntaxKind) {
let len = self.children.len();
self.parents.push((kind, len));
}
#[inline]
pub fn finish_node(&mut self) {
let (kind, first_child) = self.parents.pop().unwrap();
let children: Vec<_> = self.children.drain(first_child..).collect();
let mut node = GreenNode::new(kind, children.into_boxed_slice());
if node.children.len() <= 3 {
match self.cache.get(&node) {
Some(existing) => node = existing.clone(),
None => assert!(self.cache.insert(node.clone())),
}
}
self.children.push(node.into());
}
#[inline]
pub fn checkpoint(&self) -> Checkpoint {
Checkpoint(self.children.len())
}
#[inline]
pub fn start_node_at(&mut self, checkpoint: Checkpoint, kind: SyntaxKind) {
let Checkpoint(checkpoint) = checkpoint;
assert!(
checkpoint <= self.children.len(),
"checkpoint no longer valid, was finish_internal called early?"
);
if let Some(&(_, first_child)) = self.parents.last() {
assert!(
checkpoint >= first_child,
"checkpoint no longer valid, was an unmatched start_internal called?"
);
}
self.parents.push((kind, checkpoint));
}
#[inline]
pub fn finish(mut self) -> GreenNode {
assert_eq!(self.children.len(), 1);
match self.children.pop().unwrap() {
GreenElement::Node(node) => node,
GreenElement::Token(_) => panic!(),
}
}
}