538 lines
11 KiB
Go
538 lines
11 KiB
Go
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package parse
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import (
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"bufio"
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"bytes"
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"fmt"
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"github.com/yuin/gopher-lua/ast"
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"io"
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"reflect"
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"strconv"
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"strings"
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)
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const EOF = -1
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const whitespace1 = 1<<'\t' | 1<<' '
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const whitespace2 = 1<<'\t' | 1<<'\n' | 1<<'\r' | 1<<' '
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type Error struct {
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Pos ast.Position
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Message string
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Token string
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}
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func (e *Error) Error() string {
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pos := e.Pos
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if pos.Line == EOF {
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return fmt.Sprintf("%v at EOF: %s\n", pos.Source, e.Message)
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} else {
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return fmt.Sprintf("%v line:%d(column:%d) near '%v': %s\n", pos.Source, pos.Line, pos.Column, e.Token, e.Message)
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}
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}
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func writeChar(buf *bytes.Buffer, c int) { buf.WriteByte(byte(c)) }
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func isDecimal(ch int) bool { return '0' <= ch && ch <= '9' }
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func isIdent(ch int, pos int) bool {
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return ch == '_' || 'A' <= ch && ch <= 'Z' || 'a' <= ch && ch <= 'z' || isDecimal(ch) && pos > 0
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}
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func isDigit(ch int) bool {
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return '0' <= ch && ch <= '9' || 'a' <= ch && ch <= 'f' || 'A' <= ch && ch <= 'F'
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}
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type Scanner struct {
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Pos ast.Position
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reader *bufio.Reader
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}
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func NewScanner(reader io.Reader, source string) *Scanner {
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return &Scanner{
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Pos: ast.Position{source, 1, 0},
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reader: bufio.NewReaderSize(reader, 4096),
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}
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}
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func (sc *Scanner) Error(tok string, msg string) *Error { return &Error{sc.Pos, msg, tok} }
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func (sc *Scanner) TokenError(tok ast.Token, msg string) *Error { return &Error{tok.Pos, msg, tok.Str} }
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func (sc *Scanner) readNext() int {
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ch, err := sc.reader.ReadByte()
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if err == io.EOF {
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return EOF
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}
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return int(ch)
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}
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func (sc *Scanner) Newline(ch int) {
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if ch < 0 {
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return
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}
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sc.Pos.Line += 1
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sc.Pos.Column = 0
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next := sc.Peek()
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if ch == '\n' && next == '\r' || ch == '\r' && next == '\n' {
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sc.reader.ReadByte()
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}
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}
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func (sc *Scanner) Next() int {
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ch := sc.readNext()
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switch ch {
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case '\n', '\r':
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sc.Newline(ch)
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ch = int('\n')
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case EOF:
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sc.Pos.Line = EOF
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sc.Pos.Column = 0
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default:
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sc.Pos.Column++
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}
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return ch
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}
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func (sc *Scanner) Peek() int {
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ch := sc.readNext()
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if ch != EOF {
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sc.reader.UnreadByte()
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}
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return ch
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}
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func (sc *Scanner) skipWhiteSpace(whitespace int64) int {
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ch := sc.Next()
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for ; whitespace&(1<<uint(ch)) != 0; ch = sc.Next() {
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}
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return ch
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}
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func (sc *Scanner) skipComments(ch int) error {
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// multiline comment
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if sc.Peek() == '[' {
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ch = sc.Next()
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if sc.Peek() == '[' || sc.Peek() == '=' {
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var buf bytes.Buffer
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if err := sc.scanMultilineString(sc.Next(), &buf); err != nil {
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return sc.Error(buf.String(), "invalid multiline comment")
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}
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return nil
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}
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}
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for {
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if ch == '\n' || ch == '\r' || ch < 0 {
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break
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}
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ch = sc.Next()
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}
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return nil
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}
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func (sc *Scanner) scanIdent(ch int, buf *bytes.Buffer) error {
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writeChar(buf, ch)
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for isIdent(sc.Peek(), 1) {
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writeChar(buf, sc.Next())
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}
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return nil
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}
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func (sc *Scanner) scanDecimal(ch int, buf *bytes.Buffer) error {
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writeChar(buf, ch)
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for isDecimal(sc.Peek()) {
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writeChar(buf, sc.Next())
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}
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return nil
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}
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func (sc *Scanner) scanNumber(ch int, buf *bytes.Buffer) error {
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if ch == '0' { // octal
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if sc.Peek() == 'x' || sc.Peek() == 'X' {
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writeChar(buf, ch)
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writeChar(buf, sc.Next())
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hasvalue := false
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for isDigit(sc.Peek()) {
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writeChar(buf, sc.Next())
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hasvalue = true
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}
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if !hasvalue {
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return sc.Error(buf.String(), "illegal hexadecimal number")
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}
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return nil
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} else if sc.Peek() != '.' && isDecimal(sc.Peek()) {
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ch = sc.Next()
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}
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}
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sc.scanDecimal(ch, buf)
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if sc.Peek() == '.' {
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sc.scanDecimal(sc.Next(), buf)
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}
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if ch = sc.Peek(); ch == 'e' || ch == 'E' {
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writeChar(buf, sc.Next())
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if ch = sc.Peek(); ch == '-' || ch == '+' {
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writeChar(buf, sc.Next())
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}
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sc.scanDecimal(sc.Next(), buf)
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}
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return nil
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}
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func (sc *Scanner) scanString(quote int, buf *bytes.Buffer) error {
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ch := sc.Next()
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for ch != quote {
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if ch == '\n' || ch == '\r' || ch < 0 {
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return sc.Error(buf.String(), "unterminated string")
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}
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if ch == '\\' {
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if err := sc.scanEscape(ch, buf); err != nil {
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return err
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}
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} else {
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writeChar(buf, ch)
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}
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ch = sc.Next()
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}
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return nil
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}
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func (sc *Scanner) scanEscape(ch int, buf *bytes.Buffer) error {
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ch = sc.Next()
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switch ch {
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case 'a':
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buf.WriteByte('\a')
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case 'b':
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buf.WriteByte('\b')
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case 'f':
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buf.WriteByte('\f')
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case 'n':
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buf.WriteByte('\n')
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case 'r':
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buf.WriteByte('\r')
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case 't':
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buf.WriteByte('\t')
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case 'v':
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buf.WriteByte('\v')
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case '\\':
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buf.WriteByte('\\')
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case '"':
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buf.WriteByte('"')
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case '\'':
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buf.WriteByte('\'')
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case '\n':
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buf.WriteByte('\n')
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case '\r':
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buf.WriteByte('\n')
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sc.Newline('\r')
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default:
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if '0' <= ch && ch <= '9' {
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bytes := []byte{byte(ch)}
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for i := 0; i < 2 && isDecimal(sc.Peek()); i++ {
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bytes = append(bytes, byte(sc.Next()))
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}
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val, _ := strconv.ParseInt(string(bytes), 10, 32)
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writeChar(buf, int(val))
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} else {
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buf.WriteByte('\\')
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writeChar(buf, ch)
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return sc.Error(buf.String(), "Invalid escape sequence")
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}
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}
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return nil
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}
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func (sc *Scanner) countSep(ch int) (int, int) {
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count := 0
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for ; ch == '='; count = count + 1 {
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ch = sc.Next()
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}
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return count, ch
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}
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func (sc *Scanner) scanMultilineString(ch int, buf *bytes.Buffer) error {
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var count1, count2 int
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count1, ch = sc.countSep(ch)
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if ch != '[' {
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return sc.Error(string(ch), "invalid multiline string")
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}
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ch = sc.Next()
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if ch == '\n' || ch == '\r' {
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ch = sc.Next()
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}
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for {
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if ch < 0 {
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return sc.Error(buf.String(), "unterminated multiline string")
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} else if ch == ']' {
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count2, ch = sc.countSep(sc.Next())
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if count1 == count2 && ch == ']' {
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goto finally
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}
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buf.WriteByte(']')
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buf.WriteString(strings.Repeat("=", count2))
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continue
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}
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writeChar(buf, ch)
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ch = sc.Next()
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}
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finally:
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return nil
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}
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var reservedWords = map[string]int{
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"and": TAnd, "break": TBreak, "do": TDo, "else": TElse, "elseif": TElseIf,
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"end": TEnd, "false": TFalse, "for": TFor, "function": TFunction,
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"if": TIf, "in": TIn, "local": TLocal, "nil": TNil, "not": TNot, "or": TOr,
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"return": TReturn, "repeat": TRepeat, "then": TThen, "true": TTrue,
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"until": TUntil, "while": TWhile}
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func (sc *Scanner) Scan(lexer *Lexer) (ast.Token, error) {
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redo:
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var err error
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tok := ast.Token{}
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newline := false
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ch := sc.skipWhiteSpace(whitespace1)
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if ch == '\n' || ch == '\r' {
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newline = true
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ch = sc.skipWhiteSpace(whitespace2)
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}
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if ch == '(' && lexer.PrevTokenType == ')' {
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lexer.PNewLine = newline
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} else {
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lexer.PNewLine = false
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}
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var _buf bytes.Buffer
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buf := &_buf
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tok.Pos = sc.Pos
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switch {
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case isIdent(ch, 0):
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tok.Type = TIdent
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err = sc.scanIdent(ch, buf)
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tok.Str = buf.String()
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if err != nil {
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goto finally
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}
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if typ, ok := reservedWords[tok.Str]; ok {
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tok.Type = typ
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}
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case isDecimal(ch):
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tok.Type = TNumber
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err = sc.scanNumber(ch, buf)
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tok.Str = buf.String()
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default:
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switch ch {
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case EOF:
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tok.Type = EOF
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case '-':
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if sc.Peek() == '-' {
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err = sc.skipComments(sc.Next())
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if err != nil {
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goto finally
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}
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goto redo
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} else {
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tok.Type = ch
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tok.Str = string(ch)
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}
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case '"', '\'':
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tok.Type = TString
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err = sc.scanString(ch, buf)
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tok.Str = buf.String()
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case '[':
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if c := sc.Peek(); c == '[' || c == '=' {
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tok.Type = TString
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err = sc.scanMultilineString(sc.Next(), buf)
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tok.Str = buf.String()
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} else {
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tok.Type = ch
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tok.Str = string(ch)
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}
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case '=':
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if sc.Peek() == '=' {
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tok.Type = TEqeq
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tok.Str = "=="
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sc.Next()
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} else {
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tok.Type = ch
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tok.Str = string(ch)
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}
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case '~':
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if sc.Peek() == '=' {
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tok.Type = TNeq
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tok.Str = "~="
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sc.Next()
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} else {
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err = sc.Error("~", "Invalid '~' token")
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}
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case '<':
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if sc.Peek() == '=' {
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tok.Type = TLte
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tok.Str = "<="
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sc.Next()
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} else {
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tok.Type = ch
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tok.Str = string(ch)
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}
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case '>':
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if sc.Peek() == '=' {
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tok.Type = TGte
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tok.Str = ">="
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sc.Next()
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} else {
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tok.Type = ch
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tok.Str = string(ch)
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}
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case '.':
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ch2 := sc.Peek()
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switch {
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case isDecimal(ch2):
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tok.Type = TNumber
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err = sc.scanNumber(ch, buf)
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tok.Str = buf.String()
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case ch2 == '.':
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|
|
writeChar(buf, ch)
|
||
|
|
writeChar(buf, sc.Next())
|
||
|
|
if sc.Peek() == '.' {
|
||
|
|
writeChar(buf, sc.Next())
|
||
|
|
tok.Type = T3Comma
|
||
|
|
} else {
|
||
|
|
tok.Type = T2Comma
|
||
|
|
}
|
||
|
|
default:
|
||
|
|
tok.Type = '.'
|
||
|
|
}
|
||
|
|
tok.Str = buf.String()
|
||
|
|
case '+', '*', '/', '%', '^', '#', '(', ')', '{', '}', ']', ';', ':', ',':
|
||
|
|
tok.Type = ch
|
||
|
|
tok.Str = string(ch)
|
||
|
|
default:
|
||
|
|
writeChar(buf, ch)
|
||
|
|
err = sc.Error(buf.String(), "Invalid token")
|
||
|
|
goto finally
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
finally:
|
||
|
|
tok.Name = TokenName(int(tok.Type))
|
||
|
|
return tok, err
|
||
|
|
}
|
||
|
|
|
||
|
|
// yacc interface {{{
|
||
|
|
|
||
|
|
type Lexer struct {
|
||
|
|
scanner *Scanner
|
||
|
|
Stmts []ast.Stmt
|
||
|
|
PNewLine bool
|
||
|
|
Token ast.Token
|
||
|
|
PrevTokenType int
|
||
|
|
}
|
||
|
|
|
||
|
|
func (lx *Lexer) Lex(lval *yySymType) int {
|
||
|
|
lx.PrevTokenType = lx.Token.Type
|
||
|
|
tok, err := lx.scanner.Scan(lx)
|
||
|
|
if err != nil {
|
||
|
|
panic(err)
|
||
|
|
}
|
||
|
|
if tok.Type < 0 {
|
||
|
|
return 0
|
||
|
|
}
|
||
|
|
lval.token = tok
|
||
|
|
lx.Token = tok
|
||
|
|
return int(tok.Type)
|
||
|
|
}
|
||
|
|
|
||
|
|
func (lx *Lexer) Error(message string) {
|
||
|
|
panic(lx.scanner.Error(lx.Token.Str, message))
|
||
|
|
}
|
||
|
|
|
||
|
|
func (lx *Lexer) TokenError(tok ast.Token, message string) {
|
||
|
|
panic(lx.scanner.TokenError(tok, message))
|
||
|
|
}
|
||
|
|
|
||
|
|
func Parse(reader io.Reader, name string) (chunk []ast.Stmt, err error) {
|
||
|
|
lexer := &Lexer{NewScanner(reader, name), nil, false, ast.Token{Str: ""}, TNil}
|
||
|
|
chunk = nil
|
||
|
|
defer func() {
|
||
|
|
if e := recover(); e != nil {
|
||
|
|
err, _ = e.(error)
|
||
|
|
}
|
||
|
|
}()
|
||
|
|
yyParse(lexer)
|
||
|
|
chunk = lexer.Stmts
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
// }}}
|
||
|
|
|
||
|
|
// Dump {{{
|
||
|
|
|
||
|
|
func isInlineDumpNode(rv reflect.Value) bool {
|
||
|
|
switch rv.Kind() {
|
||
|
|
case reflect.Struct, reflect.Slice, reflect.Interface, reflect.Ptr:
|
||
|
|
return false
|
||
|
|
default:
|
||
|
|
return true
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func dump(node interface{}, level int, s string) string {
|
||
|
|
rt := reflect.TypeOf(node)
|
||
|
|
if fmt.Sprint(rt) == "<nil>" {
|
||
|
|
return strings.Repeat(s, level) + "<nil>"
|
||
|
|
}
|
||
|
|
|
||
|
|
rv := reflect.ValueOf(node)
|
||
|
|
buf := []string{}
|
||
|
|
switch rt.Kind() {
|
||
|
|
case reflect.Slice:
|
||
|
|
if rv.Len() == 0 {
|
||
|
|
return strings.Repeat(s, level) + "<empty>"
|
||
|
|
}
|
||
|
|
for i := 0; i < rv.Len(); i++ {
|
||
|
|
buf = append(buf, dump(rv.Index(i).Interface(), level, s))
|
||
|
|
}
|
||
|
|
case reflect.Ptr:
|
||
|
|
vt := rv.Elem()
|
||
|
|
tt := rt.Elem()
|
||
|
|
indicies := []int{}
|
||
|
|
for i := 0; i < tt.NumField(); i++ {
|
||
|
|
if strings.Index(tt.Field(i).Name, "Base") > -1 {
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
indicies = append(indicies, i)
|
||
|
|
}
|
||
|
|
switch {
|
||
|
|
case len(indicies) == 0:
|
||
|
|
return strings.Repeat(s, level) + "<empty>"
|
||
|
|
case len(indicies) == 1 && isInlineDumpNode(vt.Field(indicies[0])):
|
||
|
|
for _, i := range indicies {
|
||
|
|
buf = append(buf, strings.Repeat(s, level)+"- Node$"+tt.Name()+": "+dump(vt.Field(i).Interface(), 0, s))
|
||
|
|
}
|
||
|
|
default:
|
||
|
|
buf = append(buf, strings.Repeat(s, level)+"- Node$"+tt.Name())
|
||
|
|
for _, i := range indicies {
|
||
|
|
if isInlineDumpNode(vt.Field(i)) {
|
||
|
|
inf := dump(vt.Field(i).Interface(), 0, s)
|
||
|
|
buf = append(buf, strings.Repeat(s, level+1)+tt.Field(i).Name+": "+inf)
|
||
|
|
} else {
|
||
|
|
buf = append(buf, strings.Repeat(s, level+1)+tt.Field(i).Name+": ")
|
||
|
|
buf = append(buf, dump(vt.Field(i).Interface(), level+2, s))
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
default:
|
||
|
|
buf = append(buf, strings.Repeat(s, level)+fmt.Sprint(node))
|
||
|
|
}
|
||
|
|
return strings.Join(buf, "\n")
|
||
|
|
}
|
||
|
|
|
||
|
|
func Dump(chunk []ast.Stmt) string {
|
||
|
|
return dump(chunk, 0, " ")
|
||
|
|
}
|
||
|
|
|
||
|
|
// }}
|