Crate facet_path

Expand description

Path tracking for navigating Facet type structures.

This crate provides lightweight path tracking that records navigation steps through a Facet type hierarchy. When an error occurs during serialization or deserialization, the path can be used to produce helpful error messages showing exactly where in the data structure the problem occurred.

§Features

Lightweight PathStep enum that stores indices, not strings
Reconstruct human-readable paths by replaying steps against a Shape
Optional pretty feature for rich error rendering with facet-pretty

§Usage

use facet::Facet;
use facet_path::{Path, PathStep};

#[derive(Facet)]
struct Outer {
    items: Vec<Inner>,
}

#[derive(Facet)]
struct Inner {
    name: String,
    value: u32,
}

// Build a path during traversal
let mut path = Path::new(<Outer as Facet>::SHAPE);
path.push(PathStep::Field(0));      // "items"
path.push(PathStep::Index(2));       // [2]
path.push(PathStep::Field(0));      // "name"

// Format the path as a human-readable string
let formatted = path.format();
assert_eq!(formatted, "items[2].name");