traverse walk()

Walks an object tree non-recursively, visiting all values with customizable processors.

Introduction

This is the foundation traversal module used by clone, assemble, deref, and preprocess. It uses a stack-based approach to avoid recursion limits and handles circular references.

import walk from 'deep6/traverse/walk.js';

const result = [];
walk(
  {a: 1, b: {c: 2}},
  {
    processOther: (v, ctx) => result.push(v),
    circular: true
  }
);
// result contains all primitive values

API

walk(o [, options])

Arguments:

• o — a required object to traverse. It can be anything.
• options — an optional object. The following optional properties are recognized:
  • processObject — a function called for each object encountered.
  • processOther — a function called for non-object values.
  • processCircular — a function called when circular references are detected.
  • registry — a flat array of Constructor/handler pairs: [Type1, handler1, Type2, handler2, ...]. Extend with registry.push(Type, handler).
  • filters — an array of predicate functions. Return true to indicate the value was handled.
  • circular — a boolean flag to enable circular reference detection.
  • symbols — a boolean flag to include symbol properties.
  • allProps — a boolean flag to include non-enumerable properties.
  • context — a custom context object passed to processors.

Exports

• Circular — marker class for circular references.
• Command — deferred processing command class.
• processOther — default non-object processor.
• processCircular — default circular reference processor.
• processMap(fn, fnSeen) — creates a Map processor.
• postMapCircular — handles circular references in Maps.
• buildNewMap — builds a new Map from processed values.
• replaceObject — replaces values in stack with an object.
• processObject(fn, fnSeen) — creates an Object processor.
• postObjectCircular — handles circular references in Objects.
• getObjectData — extracts property descriptors and keys.
• buildNewObject — builds a new object from processed values.
• processVariable — processor for Variable instances.
• processCommand — processor for Command objects.
• setObject — sets up circular reference handling.
• registry — default registry of type handlers.
• filters — default filter functions.