Struct TopDownBuilder

pub struct TopDownBuilder { /* private fields */ }

A builder for creating parse trees by a top-down walk over the tree nodes. Each start_internal call must be paired with a finish_internal call. Nodes created within a pair of start_internal / finish_internal calls become children of the internal node.

Implementations

impl TopDownBuilder

pub fn new() -> TopDownBuilder

Create a new builder.

pub fn finish(self) -> ParseTree

Completes the building process and yields a ParseTree. Panics if there's unmatched start_internal` calls.

pub fn leaf(&mut self, symbol: Symbol, len: TextUnit)

Creates a new leaf node.

pub fn start_internal(&mut self, symbol: Symbol)

Start a new internal node.

pub fn finish_internal(&mut self)

Complete an internal node. Panics if there’s no matching start_internal call.

Trait Implementations

impl Debug for TopDownBuilder

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

Formats the value using the given formatter.

impl Default for TopDownBuilder

fn default() -> TopDownBuilder

Returns the “default value” for a type.