Struct rowan::GreenNodeBuilder

pub struct GreenNodeBuilder<T: Types> { /* private fields */ }

A builder for a green tree.

Implementations

impl<T: Types> GreenNodeBuilder<T>

pub fn new() -> Self

Creates new builder.

pub fn leaf(&mut self, kind: T::Kind, text: SmolStr)

Adds new leaf to the current branch.

pub fn start_internal(&mut self, kind: T::Kind)

Start new branch and make it current.

pub fn finish_internal(&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_internal_at. Example:

let checkpoint = builder.checkpoint();
self.parse_expr();
if self.peek() == Some(Token::Plus) {
  // 1 + 2 = Add(1, 2)
  builder.start_internal_at(checkpoint, Token::Operation);
  self.parse_expr();
  builder.finish_internal();
}

pub fn start_internal_at(&mut self, checkpoint: Checkpoint, kind: T::Kind)

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

pub fn finish(self) -> GreenNode<T>

Complete tree building. Make sure that start_internal and finish_internal calls are paired!

Trait Implementations

impl<T: Debug + Types> Debug for GreenNodeBuilder<T>where
    T::Kind: Debug,

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

Formats the value using the given formatter.