Trait TreeWalker

pub trait TreeWalker: Sized {
    type Arena;

    // Required methods
    fn apply_children<F: FnMut(&Self, &Self::Arena) -> PolarsResult<VisitRecursion>>(
        &self,
        op: &mut F,
        arena: &Self::Arena,
    ) -> PolarsResult<VisitRecursion>;
    fn map_children<F: FnMut(Self, &mut Self::Arena) -> PolarsResult<Self>>(
        self,
        op: &mut F,
        arena: &mut Self::Arena,
    ) -> PolarsResult<Self>;

    // Provided methods
    fn visit<V: Visitor<Node = Self, Arena = Self::Arena>>(
        &self,
        visitor: &mut V,
        arena: &Self::Arena,
    ) -> PolarsResult<VisitRecursion> { ... }
    fn rewrite<R: RewritingVisitor<Node = Self, Arena = Self::Arena>>(
        self,
        rewriter: &mut R,
        arena: &mut Self::Arena,
    ) -> PolarsResult<Self> { ... }
}

An implementor of this trait decides how and in which order its nodes get traversed Implemented for crate::dsl::Expr and AexprNode.

Required Associated Types

type Arena

Required Methods

fn apply_children<F: FnMut(&Self, &Self::Arena) -> PolarsResult<VisitRecursion>>( &self, op: &mut F, arena: &Self::Arena, ) -> PolarsResult<VisitRecursion>

fn map_children<F: FnMut(Self, &mut Self::Arena) -> PolarsResult<Self>>( self, op: &mut F, arena: &mut Self::Arena, ) -> PolarsResult<Self>

Provided Methods

fn visit<V: Visitor<Node = Self, Arena = Self::Arena>>( &self, visitor: &mut V, arena: &Self::Arena, ) -> PolarsResult<VisitRecursion>

Walks all nodes in depth-first-order.

fn rewrite<R: RewritingVisitor<Node = Self, Arena = Self::Arena>>( self, rewriter: &mut R, arena: &mut Self::Arena, ) -> PolarsResult<Self>

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl TreeWalker for Expr

type Arena = ()

impl TreeWalker for AexprNode

type Arena = Arena<AExpr>

impl TreeWalker for IRNode

type Arena = (Arena<IR>, Arena<AExpr>)