Struct egg::AstDepth

pub struct AstDepth;

A simple CostFunction that counts maximum ast depth.

let e: RecExpr<SymbolLang> = "(do_it foo bar baz)".parse().unwrap();
assert_eq!(AstDepth.cost_rec(&e), 2);

Trait Implementations

impl<L: Language> CostFunction<L> for AstDepth

type Cost = usize

The Cost type. It only requires PartialOrd so you can use floating point types, but failed comparisons (NaNs) will result in a panic.

fn cost<C>(&mut self, enode: &L, costs: C) -> Self::Cost where
    C: FnMut(Id) -> Self::Cost, 

Calculates the cost of an enode whose children are Costs.

fn cost_rec(&mut self, expr: &RecExpr<L>) -> Self::Cost

Calculates the total cost of a RecExpr.

impl Debug for AstDepth

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

Formats the value using the given formatter.