Struct rowan::GreenNodeBuilder

pub struct GreenNodeBuilder<'cache> { /* fields omitted */ }

A builder for a green tree.

Implementations

impl GreenNodeBuilder<'_>

pub fn new() -> GreenNodeBuilder<'static>

Creates new builder.

pub fn with_cache(cache: &mut NodeCache) -> GreenNodeBuilder<'_>

Reusing NodeCache between different GreenNodeBuilders saves memory. It allows to structurally share underlying trees.

pub fn token(&mut self, kind: SyntaxKind, text: &str)

Adds new token to the current branch.

pub fn start_node(&mut self, kind: SyntaxKind)

Start new node and make it current.

pub fn finish_node(&mut self)

Finish current branch and restore previous branch as current.

pub fn checkpoint(&self) -> Checkpoint

Prepare for maybe wrapping the next node. The way wrapping works is that you first of all get a checkpoint, then you place all tokens you want to wrap, and then maybe call start_node_at. Example:

let checkpoint = builder.checkpoint();
parser.parse_expr();
if parser.peek() == Some(PLUS) {
  // 1 + 2 = Add(1, 2)
  builder.start_node_at(checkpoint, OPERATION);
  parser.parse_expr();
  builder.finish_node();
}

pub fn start_node_at(&mut self, checkpoint: Checkpoint, kind: SyntaxKind)

Wrap the previous branch marked by checkpoint in a new branch and make it current.

pub fn finish(self) -> GreenNode

Complete tree building. Make sure that start_node_at and finish_node calls are paired!

Trait Implementations

impl<'cache> Debug for GreenNodeBuilder<'cache>

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

Formats the value using the given formatter.

impl<'cache> Default for GreenNodeBuilder<'cache>

fn default() -> GreenNodeBuilder<'cache>

Returns the “default value” for a type.