luast

Lua Abstract Syntax Tree format — unist-compliant tree specification and TypeScript types.

What is this?

This package provides the TypeScript type definitions and runtime utilities for the luast syntax tree format. luast is to Lua what esast is to ECMAScript: a language-specific AST that follows the unist specification.

Install

npm install @friday-friday/luast

Use

import type {Root, Identifier, Statement} from '@friday-friday/luast'
import {childFields, forEachChild, isStatement} from '@friday-friday/luast'

API

Types

All node types are exported as TypeScript type aliases:

• Root — top-level node (root)
• Statements — labelStatement, breakStatement, gotoStatement, returnStatement, ifStatement, whileStatement, doStatement, repeatStatement, localStatement, assignmentStatement, callStatement, functionDeclaration, forNumericStatement, forGenericStatement
• Clauses — ifClause, elseifClause, elseClause
• Expressions — identifier, binaryExpression, logicalExpression, unaryExpression, memberExpression, indexExpression, callExpression, tableCallExpression, stringCallExpression, tableConstructor
• Literals — stringLiteral, numericLiteral, booleanLiteral, nilLiteral, varargLiteral
• Table fields — tableKey, tableKeyString, tableValue
• Comment — comment
• Unions — Statement, Clause, Expression, TableField, LuastContent, LuastAnyNode, LuastNode

Child-field registry

• childFields — maps each node type to its ordered child field names
• arrayFields — maps node types to fields that contain arrays
• nullableFields — maps node types to fields that may be null
• getChildFields(node) — get child fields for a node
• forEachChild(node, callback) — iterate child nodes
• isArrayField(type, field) — check if a field is an array
• isNullableField(type, field) — check if a field is nullable

Type guards

• isStatement(node), isExpression(node), isClause(node), isTableField(node), isComment(node), isRoot(node)

Related

• @friday-friday/luast-util-visit — tree visitor
• @friday-friday/luast-util-scope — scope analysis
• @friday-friday/luast-util-from-luaparse — legacy AST converter
• @friday-friday/unified-lua — unified plugin
• @friday-friday/luaparse — Lua parser

License

MIT