luast-util-visit

Tree visitor for luast — walk Lua ASTs using the child-field registry.

What is this?

This package provides a visit function for traversing luast syntax trees. It is aware of the named child fields defined in @friday-friday/luast and supports filtering by node type, plus SKIP, REMOVE, and EXIT control flow actions.

Install

npm install @friday-friday/luast-util-visit

Use

import {visit, SKIP, REMOVE, EXIT} from '@friday-friday/luast-util-visit'

visit(tree, (node, parent, field, index) => {
  console.log(node.type)
})

// Filter by type
visit(tree, 'identifier', (node) => {
  console.log(node.name)
})

API

visit(tree, visitor)

Walk the tree depth-first, calling visitor(node, parent, field, index) on every node.

visit(tree, type, visitor)

Walk the tree but only call visitor on nodes matching type.

Visitor actions

• SKIP — do not visit children of this node
• REMOVE — remove the node from its parent
• EXIT — stop traversal immediately

Types

• Visitor — (node, parent, field, index) => VisitorAction
• VisitorAction — typeof SKIP | typeof REMOVE | typeof EXIT | void

Related

• @friday-friday/luast — tree specification and types
• @friday-friday/luast-util-scope — scope analysis
• @friday-friday/luaparse — Lua parser

License

MIT