parse

Documentation

Overview

Package parse implements lexical analysis and parsing for Lua source code.

The package provides two main components:

Scanner (lexer): Tokenizes Lua source into a stream of tokens. Handles all Lua lexical elements including identifiers, keywords, numbers (decimal and hex), strings (single/double quoted and multiline), operators, and comments. Also supports type annotation syntax extensions.

Parser: Consumes the token stream and produces an AST. Generated by goyacc from parser.go.y, it implements recursive descent parsing for Lua's grammar including statements, expressions, and type annotations.

Key entry points:

Parse(reader, name) - parse from io.Reader
ParseString(source, name) - parse from string with enhanced error messages

Errors include position information and can render Rust-style diagnostics with source context when the original source is available.

Index

• Constants
• func FriendlyTokenName(c int) string
• func Parse(reader io.Reader, name string) (chunk []ast.Stmt, err error)
• func ParseString(source, name string) (chunk []ast.Stmt, err error)
• func TokenName(c int) string
• type Error
  • func (e *Error) Error() string
  • func (e *Error) Render() string
  • func (e *Error) String() string
• type Lexer
  • func (lx *Lexer) Error(message string)
  • func (lx *Lexer) Lex(lval *yySymType) int
  • func (lx *Lexer) TokenError(tok ast.Token, message string)
• type Scanner
  • func NewScanner(reader io.Reader, source string) *Scanner
  • func (sc *Scanner) Error(tok string, msg string) *Error
  • func (sc *Scanner) Newline(ch int)
  • func (sc *Scanner) Next() int
  • func (sc *Scanner) Peek() int
  • func (sc *Scanner) Scan(lexer *Lexer) (ast.Token, error)
  • func (sc *Scanner) TokenError(tok ast.Token, msg string) *Error

Constants

const EOF = -1

const T2Colon = 57384

const T2Comma = 57382

const T3Comma = 57383

const TAnd = 57346

const TArrow = 57392

const TAs = 57371

const TAsserts = 57372

const TBang = 57394

const TBreak = 57347

const TDo = 57348

const TElse = 57349

const TElseIf = 57350

const TEnd = 57351

const TEqeq = 57378

const TExtends = 57376

const TFalse = 57352

const TFor = 57353

const TFun = 57377

const TFunction = 57354

const TGoto = 57367

const TGte = 57381

const TIdent = 57386

const TIdiv = 57391

const TIf = 57355

const TIn = 57356

const TInterface = 57369

const TIs = 57373

const TKeyof = 57375

const TLabel = 57385

const TLocal = 57357

const TLte = 57380

const TNeq = 57379

const TNil = 57358

const TNot = 57359

const TNumber = 57387

const TOr = 57360

const TQuestion = 57393

const TQuestionColon = 57395

const TReadonly = 57370

const TRepeat = 57362

const TReturn = 57361

const TShl = 57389

const TShr = 57390

const TString = 57388

const TThen = 57363

const TTrue = 57364

const TType = 57368

const TTypeof = 57374

const TUntil = 57365

const TWhile = 57366

const UNARY = 57396

Functions

func FriendlyTokenName

func FriendlyTokenName(c int) string

FriendlyTokenName converts a token type to a human-readable name for error messages.

func Parse

func Parse(reader io.Reader, name string) (chunk []ast.Stmt, err error)

Parse reads Lua source from reader and returns the parsed statement list.

func ParseString

func ParseString(source, name string) (chunk []ast.Stmt, err error)

ParseString parses Lua source from a string. Errors include source context for enhanced diagnostic rendering.

func TokenName

func TokenName(c int) string

Types

type Error

type Error struct {
	Pos     ast.Position
	Message string
	Token   string
	Source  string
}

Error represents a parse error with source location. When Source is set, Render() produces Rust-style diagnostics with context.

func (*Error) Error

func (e *Error) Error() string

func (*Error) Render

func (e *Error) Render() string

Render formats the error with source context showing the offending line and position.

func (*Error) String

func (e *Error) String() string

type Lexer

type Lexer struct {
	Stmts         []ast.Stmt
	PNewLine      bool
	Token         ast.Token
	PrevTokenType int
	PendingGT     *ast.Token // Pending '>' from split '>>'
	// contains filtered or unexported fields
}

Lexer implements the yyLexer interface for goyacc.

func (*Lexer) Error

func (lx *Lexer) Error(message string)

func (*Lexer) Lex

func (lx *Lexer) Lex(lval *yySymType) int

func (*Lexer) TokenError

func (lx *Lexer) TokenError(tok ast.Token, message string)

type Scanner

type Scanner struct {
	Pos ast.Position
	// contains filtered or unexported fields
}

Scanner tokenizes Lua source code into a stream of tokens.

func NewScanner

func NewScanner(reader io.Reader, source string) *Scanner

NewScanner creates a scanner for the given input with the specified source name.

func (*Scanner) Error

func (sc *Scanner) Error(tok string, msg string) *Error

func (*Scanner) Newline

func (sc *Scanner) Newline(ch int)

func (*Scanner) Next

func (sc *Scanner) Next() int

func (*Scanner) Peek

func (sc *Scanner) Peek() int

func (*Scanner) Scan

func (sc *Scanner) Scan(lexer *Lexer) (ast.Token, error)

Scan reads and returns the next token from the input.

func (*Scanner) TokenError

func (sc *Scanner) TokenError(tok ast.Token, msg string) *Error