luast-util-scope

Scope analysis for luast trees — identify local and global identifiers.

What is this?

This package walks a luast syntax tree and determines which identifiers are local and which are global. It understands all Lua scoping rules: local declarations, function parameters, for loop variables, and nested block scopes.

Install

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

Use

import luaparse from '@friday-friday/luaparse'
import {analyzeScope} from '@friday-friday/luast-util-scope'

const tree = luaparse.parse('local x = 1; print(x)', {ast: 'luast'})
const scope = analyzeScope(tree)

console.log(scope.globals)
// => [{type: 'identifier', name: 'print', …}]

console.log(scope.isLocal(tree.body[1].expression.base))
// => false (print is global)

API

analyzeScope(tree)

Analyze scopes in a luast Root tree.

Returns a ScopeInfo object:

• globals — array of Identifier nodes that are global
• isLocal(node) — returns true if the given Identifier node is local

Related

• @friday-friday/luast — tree specification and types
• @friday-friday/luast-util-visit — tree visitor
• @friday-friday/luaparse — Lua parser

License

MIT