Struct regex_syntax::ast::visitor::HeapVisitor

struct HeapVisitor<'a> {
    stack: Vec<(&'a Ast, Frame<'a>)>,
    stack_class: Vec<(ClassInduct<'a>, ClassFrame<'a>)>,
}

HeapVisitor visits every item in an Ast recursively using constant stack size and a heap size proportional to the size of the Ast.

Fields

stack: Vec<(&'a Ast, Frame<'a>)>

A stack of Ast nodes. This is roughly analogous to the call stack used in a typical recursive visitor.

stack_class: Vec<(ClassInduct<'a>, ClassFrame<'a>)>

Similar to the Ast stack above, but is used only for character classes. In particular, character classes embed their own mini recursive syntax.

Implementations

impl<'a> HeapVisitor<'a>

fn new() -> HeapVisitor<'a>

fn visit<V: Visitor>( &mut self, ast: &'a Ast, visitor: V, ) -> Result<V::Output, V::Err>

fn induct<V: Visitor>( &mut self, ast: &'a Ast, visitor: &mut V, ) -> Result<Option<Frame<'a>>, V::Err>

Build a stack frame for the given AST if one is needed (which occurs if and only if there are child nodes in the AST). Otherwise, return None.

If this visits a class, then the underlying visitor implementation may return an error which will be passed on here.

fn pop(&self, induct: Frame<'a>) -> Option<Frame<'a>>

Pops the given frame. If the frame has an additional inductive step, then return it, otherwise return None.

fn visit_class<V: Visitor>( &mut self, ast: &'a ClassBracketed, visitor: &mut V, ) -> Result<(), V::Err>

fn visit_class_pre<V: Visitor>( &self, ast: &ClassInduct<'a>, visitor: &mut V, ) -> Result<(), V::Err>

Call the appropriate Visitor methods given an inductive step.

fn visit_class_post<V: Visitor>( &self, ast: &ClassInduct<'a>, visitor: &mut V, ) -> Result<(), V::Err>

Call the appropriate Visitor methods given an inductive step.

fn induct_class(&self, ast: &ClassInduct<'a>) -> Option<ClassFrame<'a>>

Build a stack frame for the given class node if one is needed (which occurs if and only if there are child nodes). Otherwise, return None.

fn pop_class(&self, induct: ClassFrame<'a>) -> Option<ClassFrame<'a>>

Pops the given frame. If the frame has an additional inductive step, then return it, otherwise return None.